Geophysical Monitoring 

for Climatic Change 

No. 8 

Su rv Reporl 1979 

U.S. DEPARTMENT 

OF COMMERCE 

NATIONAL 

OCEANIC AND 

ATMOSPHERIC 

ADMINISTRATION 

ENVIRONMENTAL 

RESEARCH 

LABORATORIES 

~ • 

• 

4;~ ... '\ (e 

• 

· l 
Geophysical Monitoring 

for Climatic Change 

NO.8 

Summary Report 1979 

Gary A. Herbert, Editor 

December 1980 

Boulder, Colorado 

U.S. DEPARTMENT OF COMMERCE 

Philip M. Klutznick, Secretary 

National Oceanic and Atmospheric Administration 

Richard A. Frank, Administrator 

Environmental Research Laboratories 

Joseph O. Fletcher, Acting Director 
NOTICE 

Mention of a commercial company or product does not constitute an endorsement by NOAA Environmental Research 

Laboratories. Use for publicity or advertising purposes 

of information from this publication concerning proprietary products or the tests of s uch products is not authorized. 

ii 
CONTENTS 

ACRONYMS AND ABBREVIATIONS 

FOREWORD 

1. 

2. 

3. 

4. 

5. 

SumlARY 

OBSERVATORY FACILITIES 

2.1 Mauna Loa, Hawaii 

2.2 Point Barrow, Alaska 

2.3 Samoa 

2.4 South Pole 

CONTINUING GMCC PROGRAMS 

3.1 

3.2 

3.3 

3.4 

3.5 

3 . 6 

3.7 

3.8 

3.9 

3 . 10 

3.11 

3.12 

Carbon Dioxide 

Total OZone 

Ozone Vertical Distribution 

Surface Ozone 

Stratospheric Water Vapor 

Halocarbons and N2 0 

Surface Aerosols 

Solar Radiation Measurements 

Meteorological Measurements 

Precipitation Chemistry 

Meteorological Trajectories 

Data ~Ianagement 

GMCC SPECIAL PROJECTS 

4 . 1 

4.2 

4.3 

4.4 

4.5 

4.6 

4 . 7 

Optical Effects of Aerosols on Umkehr Measurement 

Disparities in Ozone Measurement 

Selection of CO 2 Values from Whole Air Samples 

North Carolina Turbidity Data 

Barrow CO 2 , Aerosol, and Ozone Dependence on Air Trajectories 

GMCC and SIO CO 2 Measurements at Mauna Loa 

Signatures in Atmospheric Transmission Variations at Mauna Loa 

COOPERATIVE PROGRAMS 

5.1 

5.2 

5.3 

5.4 

5.5 

5.6 

5.7 

5.8 

Air Chemistry Studies at Barrow (URI) 

Soot in the Arctic (Univ. of Calif.) 

Chemical Composition of Atmospheric Aerosols (Univ. of Md.) 

Nuclear Fallout and High Volume Aerosol Collections (DOEjEML) 

Attenuation of Solar Radiation by Atmospheric Particles 

at MLO (Ctr. Environ. & Man) 

MLO Solar Spectral Irradiance Program (Univ. of Alaska) 

UV Erythema Global Measuring Network (Temple Univ.) 

Ozone and Solar Radiometry (San Diego St. Univ . ) 

iii 

Page 

iv 

v 

1 

2 

2 

7 

9 

11 

16 

16 

23 

26 

26 

31 

31 

35 

41 

51 

56 

58 

60 

65 

65 

68 

69 

73 

75 

76 

78 

82 

82 

84 

88 

94 

95 

98 

99 

99 
5.9 

5.10 

5.11 

5.12 

5.13 

5.14 

Satellite Determination of Ozone (NOAA-NWS) 

Daily Sunspot Count (Dept. Commerce/EDIS) 

Precipitation Chemistry at S~10 and HLO (DOE/HIL) 

Drifting Snow at BRW (Univ. of Alaska) 

Recalibration of Pollak Counter at 680-mb (SUNYA) 

Heasurement of S02 and TSP at MLO (Dept. of Health, 

101 

101 

103 

104 

105 

Hawaii) 108 

6. INTERNATIONAL ACTIVITIES 109 

7. PUBLICATIONS AND PRESENTATIONS III 

8. REFERENCES 115 

9. G~ICC STAFF 119 

AFGL 

APCL 

ARL 

BRW 

CAF 

CSRID 

DOE 

EDIS 

EHL 

EPA 

G.E. 

ICDA& 

LBL 

LST 

HLO 

HPI 

NARL 

NIP 

NOAA 

NRC 

NSF 

NWS 

OGC 

SID 

SHO 

SPO 

SRL 

SUNYA 

URI 

WHO 

ACRONYNS AND ABBREVIATIONS 

Air Force Geophysical Laboratory, Hanscom Air Force Base, Mass. 

Atmospheric Physics and Chemistry Laboratory, Boulder, Colo. (NOAA) 

Air Resources Laboratories, Washington, D.C. (NOAA) 

Barrow Observatory, Barrow, Alaska (GMCC) 

Clean Air Facility, South Pole Observatory, Antarctica (GMCC) 

Commonwealth Scientific and Industrial Research Organization, Australia 

U.S. Department of Energy 

Environmental Data and Information Service, Washington, D.C. (NOAA) 

Environmental Measurements Laboratory, U.S. Department of Energy, 

New York, N.Y. 

Environmental Protection Agency 

General Electric 

instrument controlled data acquisition system 

Lawrence Berkeley Laboratory 

Local standard time 

Mauna Loa Observatory, ~launa Loa, Hawaii (GMCC) 

Max Planck Institute, ~Iainz, Germany 

Naval Arctic Research Laboratory, Barrow, Alaska 

normal incidence pyrheliometer 

National Oceanic and Atmospheric Administration, U.S. Dept. of 

Commerce 

National Research Council 

National Science Foundation, Washington, D.C. 

National Weather Service, Washington, D.C. (NOAA) 

Oregon Graduate Center, Beaverton, Ore. 

Scripps Institution of Oceanography, La Jolla, Calif. 

Samoa Observatory, American Samoa (GMCC) 

South Pole Observatory, Antarctica (GMCC) 

Smithsonian Institution Radiation Biology Laboratory 

State University of New York at Albany 

University of Rhode Island, Kingston, R.I. 

World Neteorological Organization, Geneva, Switzerland 

iv 
FOREWORD 

The invention of i nstruments and measurement techniques to document the 

courses of meteoro logical elements was not an accomplisrunent sufficient unto 

itself. It was recognized long ago that although the diurnal and seasonal cycles 

of many elements are reasonably predictable in a general sense, in detail and 

precise magnitude they are highly variable and sensitive to local environmental 

circumstances--circurnstances that could compromise the detection of significantly 

representative long term trends . To minimize or stabilize local influences, an 

observatory system was established similar to t he Kew Observatory in Eng l and in 

the 18th century and the Abbe Observatory in Ohio and the Mt. Weather Observatory 

in Virginia. The sites were selected in rural or park-land settings, relatively 

free from drastic local environmental deterioration. However, the intensive 

urbanization in the decades about the turn of this century and the shifting of 

many observing s ites, for economic reasons, to more urbanized locations near 

governmental office buildings downgraded the environments surrounding sites. Many 

observatory sites were shifted to airports in the 1930's to accommodate the expanding aviation industry and to provide information for day-to-day forecasting, but 

such sites had minimal utility for meteorologica l research. 

In the late 1950 's monitoring programs, inspired by the activities connected 

with the International Geophysical Year, intensified attention on atmospheric 

composition (e.g., CO 2 and 0 3 ) . At about this time, the late Dr. Harry Wexler and 

others began to signifi cantly upgrade the Mauna Loa program. But until well into 

the 1960's littl e concern was directed toward long term climatic changes or trends 

except on geologica l time periods or by temporary and spatially limited aberrations 

caused by natural phenomena such as volcanic eruptions. Then three developments 

pointed out that not only was an i mportant climatic change perhaps in progress, 

but also that human activities could be contributing factors: 

(1) Data were published indicating a world-wide downward trend in surface 

air temperature, at least in the Northern Hemisphere. This trend in the late 

1930's followed an upward trend that had been persisting from before the turn of 

the century. 

(2) The atmospheric CO 2 l evels on Mauna Loa showed a definite upward annual 

trend. 

(3) Turbidity data indicated that the aerosol loading of the atmosphere 

might be on t he upswing and playing an importanL role in the energy balance of the 

earth-atmosphere system. 

Although questions about the sign and magnitude of factors (1) and (3) were 

hotly debated, the discussions directed attention to the need for reliable long 

term data on human impact on climate and atmospheric composition, and the magnitude of climatic change . 

Concern in the United States crystallized in 1970 with the Study of Man's 

Impact on the Global Environment and an assessment and recommendations for action. 

An Expert Task Group, formed by the World Meteorological Organization, proposed 

guidelines and criteria for establishing a baseline global atmospheric monitoring 

network by national weather services. These recommendations were echoed in 1972 

and 1973 by a tas k group of the International Council of Scientific Unions. 

v 
This Summary Report 1979 describes the Geophysical Monitoring for Climatic 

Change (GMCC) program, which has operated for eight years. The siting of the four 

observatories, the scientific data, and r esulting s tudies meet the fundamenta l 

objectives of global atmospheric monitoring to the greatest ext ent that geographic 

circumstances and human ingenuity can achieve. Particular credit must be given to 

D. H. Pack, whose tireless dedi ca tion and creative inspiration were so instrumental 

in the successful genesis of GMCC. Tribute should also be given to the on-site 

scientific staffs who work in extreme conditions mostly in barren settings devoid 

of any aura of romanticism whi ch their exotic place-names imply. 

Robert A. McCormick 

Former Director of the Meteorology Laboratory 

Air Reso urces Laboratories, NOAA 

vi 
GEOPHYSICAL MONITORING FOR CLIMATIC CHANGE 

NO. 8 

Summary Report 1979 

1. Sill~Y 

The mo st significant cha nge in the GMCC operational program in 1979 was the 

initiation of 10 additional CO 2 flask sampling stations. Flask sampling was 

previously conducted at 3 maritime locations in addition to the 4 GMCC baseline 

stations. Most of the 10 new stations are located at coastal sites in the tropics 

and polar zones. The flask analysis calibration procedure was converted from CO 2-

in-N2 to CO 2 -in-air as of January 1979. 

Continuous measurement of CO 2 and aerosol sca ttering at four wavelengths, 

using a nephelometer , was begun at the South Pole station at the end of 1978 and 

continued throughout 1979. Other meas urement programs operated without serious 

interruption throughout the year. 

Only minor changes and improvements were made to the stations. The main 

concern involved the future of the Barrow station because of the pending shutdown 

of the Naval Arctic Research Laboratory. The staff began locating alternate 

power, repair facilities, and housing. At the Mauna Loa Observatory the main 

concern was the temperature oscillations induced by air conditioner cycling. A 

S-yr lea se agreement was negotiated with the local ch;~f i n Samoa. 

A filter collection system was installed at the Barrow station to make 

possible the determination of the mass of the carbonaceous aeroso ls . The analysis 

is performed by H. Rosen of the University of California. Early results show that 

graphitic carbon makes up a significant part of the arctic haze, and because of 

its optical absorptivity, it may cause a significant contribution to the radiative 

energy budget. 

At MLO a new cooperative measurement program to observe the chemical composition of aerosols was initiated. By considering the times when the flow is free of 

l ocal contamination, changes in sources can be evaluate d. The filter will be 

analyzed by W. H. Zoller of t he University of Maryland. 
2. OBSERVATORY REPORTS 

2.1 Mauna Loa 

2 .1.1 Facilities 

The following modifications to the Mauna Loa facilities were effected in 1979: 

(1) Ultraviolet pyranometer no . 10232 was replaced by no. 12350 on 

31 January. 

(2) Pyrheliometer filter wheel no. 13911 was replaced by no. 13910 on 

26 January. 

(3) Equipment for a cooperative program with W. Zoller, University of 

Maryland, was installed 12 February. 

(4) Pyranometer no. 12560 was replaced by no. 12502 on 11 April. 

(5) The 5/B-in ruby rod in the lidar was replaced by a 3/B-in rod on 

24 April. 

(6) A new main frame for the ICDAS computer was installed in early April. 

(7) A new dew cell was placed in operation on 25 May. 

(B) The nitrogen dioxide analyzer was returned to Boulder in mid-June 

because the program was suspended in April. 

(9) The filter heads and cartridges of the EML directions wind sampling 

equipment were replaced with modified versions in May. 

(10) A special clean bench for changing University of Maryland filters was 

installed on 22 June . 

(11) A millipore deionized water still and an Aerochemetric wet-dry precipitation collector were delivered to MLO in June. 

(12) The central air conditioner at the main observatory was modified in 

July to give more stable temperatures in the building. 

(13) The 3-M copier in the Hilo office was replaced by a Xerox 2600 on 

1 October. 

(14) The polarizing radiometer system, acquired on a 5-yr loan from the 

University of California, Davis, was delivered to MLO on 19 November. 

(15) The gust recorder scale was changed from knots to miles per hour during 

December. 

(16) Room 205 of the Federal Building, Hilo, was assigned to MLO on 

17 December. 

( 17) Special museum display cabinets built for ~lLO by Hilo Community College 

were delivered to room 205 on 21 December. 

2 
(18) Equipment for a cooperative program with T. Ca hill, University of California, Davis, was installed on 29 December . 

2. 1. 2 Programs 

Table 1 lists the programs carried out at MLO during 1979. Brief status 

reports on t he principal programs follow. 

Carbon Dioxide 

The URAS -2 and Applied Physics nondispersive infrared gas ana lyzers used for 

monitoring ca rbon dioxide concentration were operated continuous ly without major 

problems during 1979. 

Pairs of GMCC glass flas ks used for collecting CO 2 air sampl es were exposed 

weekly at MLO and Cape Kwnukahi, and pairs of 5-Q flasks were exposed for SIO on 

alternate weeks at the same l ocations. Two methods were used interchangeably for 

filling flasks at the obse rvatory. The normal method , which used a small, hand 

operated aspirator, was rep l aced on alternate weeks by pumping air into the flasks 

from the air flow system of the URAS-2 analyzer. In the latter method, the measured flask concentra tion could be corroborated by data taken simultaneous ly with 

the analyzer . 

Outgassing from the volcanic caldera at the s ummit of Mauna Loa was recorded 

occasionally i n t he CO 2 measurements. Such outgassing occurred mainly between 

midnight and 8 a .m. local time during a downslope wi nd flow r egime on the mountain. The monthly frequency of occurrence of the outgassing recorded in 1979 was 

as follows: 

No. of days 

Percent of 

days 

J F M A M J J A S o N D 

5 15 12 9 16 13 10 9 10 11 6 5 

16% 43% 39% 30% 52% 43% 32% 29% 33% 35% 20% 16% 

The average frequency (32%), the same as for 1978, is somewhat lower than the 42% 

and 43% that occurred i n 1976 and 1977 after the J uly 1975 eruption of Mauna Loa . 

Atmospheric Ozone 

Total ozone i n the atmosp heric column was measured three times a day, on 

approximately 260 days during 1979. I n addition, a special se ries of total ozone 

measurements was conducted for 2 months during the s ummer. Concentration of ozone 

in air near the surface was monitored continuously with Dasibi a nd ECC ozone 

meters. 

Atmospheric Aerosols 

The aeroso l monitoring programs continued with only minor interruptions 

during the year. The principal parameters of the measurements are volume scattering coefficient of the air and concentration of condensation nuclei in the air. 

3 
Table l.--Summary of monitoring programs at Mauna Loa in 1979 

~lonitoring Program 

Gases 

--ca;:-bon dioxide 

Carbon dioxide 

Surface ozone 

Surface ozone 

Total ozone 

Fluoroca rbons 

Aerosols 

Stratospheric aerosols 

Condensation nu clei 

Conde nsation nuclei 

Optica l properties 

Solar radiation 

Global irradiance 

Ultraviolet irradiance 

Direct beam irradiance 

Direct beam irradiance 

Direct beam irradiance 

Meteorology 

Maximum temperature 

Minimum temperature 

Ambient temperature 

Ambient temperature 

De~ point temperature 

Relative humidity 

Total precipitable ~ater 

Pressure 

Pressure 

Precipitation 

PreCipitation 

Precipitation 

Windspeed 

Wind direction 

Precipitation chemistry 

Acidity of rainwater 

Conductivity of water 

Chemical components 

Cooperative programs 

Carbon dioxide (SIO) 

Carbon monoxide (MP!) 

Surface S02 (EPA) 

Total surface particulates 

(DOE) 

Instrument 

URAS-2 infrared gas analyzer 

Evacuated gLass flasks 

Electrochemical concentration cell 

Dasibi ozone meter 

Dobson spectrophotometer 

Pressurized flasks 

Lidar 

Pollak CN cou nter 

G.E. CN counter 

4-~avelength nephelometer 

4 Eppley pyranometers 

Eppley ultraviolet pyranometer 

Eppley pyrheliometer 

Eppley pyrheliome ter with filters 

Eppley 13-channel pyrheliometer 

Maximum thermometer 

Minimum thermometer 

Thermistor 

Hygrothermograph 

De~ point hygrometer 

Hygrothermograph 

Faskett infrared hygrometer 

Electronic pressure transducer 

Microbarograph 

Rain gage, 8-in 

Rain gage, 8-in 

Rain gage. tipping bucket 

Anemometer 

Wind vane 

pH meter 

Conductivity bridge 

Ion chromatograph 

Infrared analyzer (Applied Physics) 

Evacuated flasks 

Special system 

Chemical bubbler system 

High volume filter 

Sampling 

frequency 

Continuous 

Weekly 

Continuous 

Continuous 

Discrete 

Weekly 

Weekly 

Discrete 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

Discrete 

Continuous 

Da ily 

Daily 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

COlltinuous 

Dail:i 

2 wk 1 

Continuous 

Continuous 

Continuous 

Discrete 

Discrete 

Discrete 

Continuous 

8 mo- I 

C9ntinuous 

Every 12 days 

Continuous 

Total surface particulates High volume filter 

(EPA) 

Every 12 days 

Atmospheric electricity 

(APCL/ NOAA) 

Stratospheric aerosols 

(MGL) 

Ultraviolet radiation 

(Temple Univ.) 

Precipitation collection 

(DOE) 

Precipitation collection 

(EPA) 

PreCipitation co llecti on 

(Oniv. of Paris) 

Precipitation coll ection 

(IAEA, Vienna, Austria) 

Atmospheric aerosols 

(Oniv. of Md.) 

AtmospheriC aerosols 

(Florida State Univ. 

Atmospheric aerosols 

(Oniv. of Calif.) 

Field mill, air conductivity meter, Continuous 

surface antenna 

Twilight photometer Continuous 

Ultraviolet radiometer 

Wet-dry Health & Safety Lab 

collector 

Misco model 93 

Likens funnel collector 

Likens funnel collector 

Nuclepore and qua rtz fi 1 te rs 

Special filters 

Nuciepore filters and impactors 

4 

Continuous 

Continuous 

Continuous 

2 wk- I 

2 wk- I 

Cont inuous 

Continuous 

Night only 

Remarks 

Mountain and seacoast 

3 meas. weekdays; 0 weekends 

694.3 nm, 1 J 

5 meas. weekdays; 0 weekends 

Wavelengths 450, 550, 700, 850 rum 

Cutoff filters at 280, 390, 530, 

695 nm 

Wavelength range 295 to 385 nm 

Wavelength range 280 to 3,000 nm 

Cutoff filters at 280, 530, 630, 

695 nm 

At HLO and Kulani Hauka 

At MLO and Kulani Hauka 

At MLO 

At Kulani Mauka 

Rain~ater collections at 6 sites 

Mountain and seacoast 

Chemical reaction with lIgO 

Dependent on wind direction 

Radiation responsible for s unburning of skin 

Day-night discrimination 

Installed in late December 
Lidar Observations 

In contrast to mo st flLO programs, the lidar program was l ess than successful 

during 1979. It is thought, however, that any clouds of volcanic ash in the 

stratosphere could have been detected had they occurred. The Biomation component 

of the system was returned to the factory for repairs on two occasions, and the 

power output of t he laser was always low and erratic. The operation was so 

marginal that in Septemb er a major refurbishing of the system was deemed necessary 

for reliable operation . Consequently, a new ruby rod was purchased and the old 

one repolished, the Pockels cell was checked a nd repolished, new mirrors were 

purchased, and a new flash lamp was install e d . Because of extensive repairs, the 

system was not in operation during the last 4 months of the year, but measurements 

were expected to begin again early in 1980. 

Solar Radiation 

Solar radiation measurements continued without essential problems throughout 

1979. The 13-channel pyrheliometer was in operation all year, but it is without 

calibration. Efforts to get Eppley Laboratories to refurbish and recalibrate one 

unit for use at flLO were not successful, so at present only relative flux values 

are available for the instrument. 

Meteorological Parameters 

Tempe rature, pressure, wind, and other meteorological parameters were monitored routinely with few problems. A new dew cell for dew point mea surements, 

installed in February, operated the remainder of the year. An occasional ambiguity of lROo in wind direction resulting from a defective winding in one of the 

synchro units of the wind vane was corrected in late December, and at the same 

time the unit of wind speed for the recorder was changed from knots to miles per 

hour. 

Precipitation Chemistry 

The program continued in 1979 with few changes. A Kauai water collection 

site was added to investigate the effects of an island with no active volcano. A 

reverse osmosis deionizing water still was installed to i mprove rainwater analyses 

on the DIONEX chromatograph. Besides improving the quality of the water, the unit 

is semi-automatic, so that clean water is always on hand for solution preparation, 

labware cleaning, and plasticware cleaning. 

Fluorocarbons (Halocarbons) 

This low effort program continued in 1979 without difficulty. Weekly air 

samples taken at the observatory were shipped to the Boulder laboratory for 

analysis. 

Cooperative Programs 

Most cooperative programs listed in table 1 were continued t h rough 1979 

without major difficulties. A modified procedure for the acceptance of cooperative proj e cts was instituted in 1979. Since a written project plan is now required, better control of the experiment and more consistent relations with the 

coope rators are expected. 

5 
Carbon monoxide measurements (MPI): This program was continued until midOctober, when the equipment failed. Repairs were not attempted because the 

German scientists were expecting to replace the outmoded system with a new one 

early in 1980. 

Arosol collections (Fla. State Univ.; Univ . of Md.; Univ. of Calif., Davis) : 

Three types of aerosol collectors were installed by cooperators during 1979. A 

traveling orifice in a small filter device from Florida State University causes 

particles to be laid down in a 5-in-long strea k over a 2-wk period. In a more 

elaborate installation from the University of Maryland, two pumps fitted with 

Nuclepore and quartz filters are operated at night, and a third with a Nuclepore 

filter operates during the day; the time discrimination is an attempt to separate 

out particles from upslope and dOl<mslope wind regimes. The third aerosol collector is a hybrid filter-impactor device from the University of California, Davis. 

The aerosol samples from all installations are analyzed by the respective Principal Investigators for the chemica l composition of the particles. 

A lO-channel photometer and a corona meter were operated for several days in 

April by G. Shaw of the University of Alaska. 

A 1-yr study of the chemistry of precipitation in the vicinity of Kilauea 

Volcano by D. Harding was completed during March 1979. This study was sponsored 

by the National Research Council (NRC) associateship program. 

A second NRC associate, A. Dittenhoefer, began a 1-yr project at MLO on the 

chemistry of aerosols during early December 1979. 

~leasurelllents of sulfur dioxide (EPA): No changes were made in operational 

procedures during 1979. The unit functioned normally during sampling intervals. 

Analytical techniques may be updated at the central laboratory in Honolulu to 

alleviate temperature related problems. 

Collection of atmospheric particulates (EPA): The high volume samples were 

run continuously to collect total particulates. No changes of equipment were made 

during the year, and no particular problems were encountered. 

Precipitation chemistry (EPA): tlonthly precipitation samples were sent to 

the EPA laboratory in North Carolina. 

PrecipiLation chemistry (DOE): The wet-dry fallout samplers operated normally throughout 1979, and samples were mailed monthly to New York. 

Collection of atmospheric particulates (DOE): The only equipment change 

during the year was the provision of a different tyPe of manifold to which the 

filters do not adhere. This greatly simplifies filter changes. One interesting 

observation is that the nighttime filters, used during the predominantly downslope 

flow regime (2100 to 0600 LST) , were generally cleaner than those of the daytime 

upslope flow regime (0600 to 2100). This is the reverse of the prevailing situation during much of 1978 but corresponds to observations in previous years. 

ICDAS Data Acquisition System 

Two significant changes of the ICDAS system were made during 1979. In 

February a modified control program (BOSS 79001) was put into operation, and a new 

carbon dioxide control board was installed. These improvements increased system 

6 
reliability and greatly reduced the possibility of rapid loss of carbon dioxide 

reference gas during computer failure. In April a NOVA 1220 computer chassis with 

a linear power supply was installed, reducing electrical noise and improving 

quality of the analog signals. 

The main problems with the data acquisition system during 1979 were system 

outages caused by sporadic rewinding of the tape and a rash of thunderstorms 

during the fall months that burned out electronic components and caused system 

downtime periods. 

2.2 Barrow 

2.2.1 Facilities 

The lidar observatory wanigan was completed and located in August 1979. 

However, as the winter progressed drifting snow caused by the wanigan's proximity 

to other buildings caused access problems and may force consideration of another 

location. 

The Thomas E. DeFoor Memorial Walkway from the station to the tower, aerosol 

platform, and Dobson dome was completed in September. The walkway, named in honor 

of the former station chief, saves many wet and boggy steps in the summertime. 

Hut 164 at NARL (Naval Arctic Research Laboratory) was obtained for housing 

GMCC staff. Previously, single members lived in the main lab building, at greater 

cost to GMCC. 

Extensive renovation work on the station road was completed in August. A 

binder mixture of gravel and clay was spread to harden and stabilize the road's 

surface, with satisfactory results. 

2.2.2 Programs 

Programs carried out at BRW during 1979 are listed in table 2. 

Several modifications were made to the ICDAS system in 1979. The NOVA 

mainframe was upgraded with a linear power supply and installed in April, and a 

new multiplexer was installed in July . The magnetic tape drive, adapter, and 

associated NOVA control board were exchanged for those from the Boulder prototype 

station to try to cure a spurious tape drive reversal problem that still persists 

on a very intermittent basis. Environmental causes are being investigated. 

A cooperative project to investigate carbonaceous particles in the atmosphere 

was initiated with Lawrence Berkeley Laboratory in October. Filter samples are 

run for 4 days and then sent to LBL for analysis. 

Two programs were terminated in 1979: the NOAA/Aeronomy Lab N0 2 project in 

May and operation of GMCC's ECC ozone meter in June. 

The University of Rhode Island sampling sector controller, which runs URI's 

high volume samplers only when the wind is from the clean sector, was installed in 

December. 

7 
Table 2. --Summary of sampling programs at Barrow in 1979 

Monitoring program 

Gases 

Carbon dioxide 

Surface ozone 

Halocarbons 

Total ozone 

Aerosols 

Condensation nuclei 

Optical properties 

Solar radiation 

Global spectral irradiance 

Direct spectral irradiance 

Turbidity 

Meteorology 

Air temperature 

Relative humidity 

Air pressure 

Wind (speed and direction) 

Ground temperature 

Precipitation chemistry 

pH a nd conductivity 

Cooperative programs 

Total surface particulates 

(DOEjEUI) 

Arctic haz e particulates 

(URI) 

Global radiation 

(SRL) 

CO 2 sampling (510) 

Precipitation gage (Soil 

Conservation Service) 

Carbonaceous particles 

(Lawrenc e Berkeley Lab.) 

Instrument Sampling frequency 

URAS-2T infrared analyzer 

Glass fla sk pairs 

Dasibi ozone me ter 

Flask samples 

Dobson spectrophotometer 

G.E. CN counter 

Pollack counter 

4-wavelength nephelometer 

4 Eppley pyranometers 

with Q1, GG22, OG1 and 

RG8 filte rs 

Eppley normal incidence 

pyrheliometer with filter 

wheel 

Eppley s unpho tome ter 

Thermistor 

Hygrothermograph' 

Dew point hygrometer 

Sling psyc h rometer 

Transducer 

Mi crobarograph 

Mercurial barometer 

Bendix aerovane 

Thermistor 

Wide mouth polyethylene 

collector (sa~ples 

analyzed at 1110) 

Collection of snow on tundra 

(sample s analyzed at I1LO) 

High volume sampler 

High volume samplers 

Radon monitors 

Eppley pyranometers 

Temple Univ. sunburning meter 

Flask samples 

Wyoming shielded pre cipita -

tion gage 

High vo lume sampler 

Surface s now samples 

8 

Continuous 

1 pair wk- 1 

Continuous 

1 pair wk - 1 

3 day-1 

Continuous 

Discrete 

Continuous 

Continuous 

Discrete 

Discrete 

Continuous 

Continuous 

Continuous 

Discrete 

Continuous 

Continuous 

Discrete 

Continuous 

Continuous 

Discrete 

Continuous 

Continuous 

Discrete 

Continuous 

Continuous 

2 sets mo- 1 

2 readings mo- 1 

Continuous 

2 mo- 1 
2.3 Samoa 

2.3.1 Facilities 

No major additions to the Samoa GMCC facility were made during 1979. The 

lease agreement was renegotiated between NOAA and High Chief luli Togi for the 

land on which the GMCC facility is located. N. Stiewig from Research Support 

Services arrived on the island during January and negotiated the new settlement. 

A unique feature of the renegotiation was lump swn advance payment, which was used 

to construct a Samoa style guest house for the luli family in Tula village. 

Construction was begun in November 1979 and completed in early 1980. The structure has been useful and practical for the luli family and Tula village. N. 

Stiewig's role in suggesting this plan and incorporating it in the lease documentation and payment schedule is gratefully acknowledged. Local individuals involved in the renegotiation were High Chief luli Togi, Lt. Governor Tufele Lia, 

who signed the document approving the communal land lease between NOAA and High 

Chief luli (all communal land leases must be approved by the Governor's office and 

the local attorney general's office), L. Richmond, assistant to the Governor, and 

Tauivi Tuinei, attorney for the luli family. This renegotiation is binding for 

the next 5-yr period. 

2.3.2 Programs 

Table 3 lists the programs carried out at SMO during 1979. Status reports on 

the principal programs follow. 

Trace Gases 

Carbon Dioxide: Continuous CO 2 analyzer data were significantly improved in 

February 1979 when the polyethylene sample line system was modified, resulting in 

index values more in agreement with those obtained in hand aspirated flasks exposed in the vicinity of the actual polyethylene line intake. To eliminate recurrence of what appeared to be diffusion effects on the polyethylene line, an aluminum sample line was installed in May 1979 and became the primary sample line. 

Coinciding with the new air line installation, a special CO 2 flask sampling program was initiated to more thoroughly document air line effects. Thus, twice 

weekly flask samplings were begun. A sampling consisted of four flasks, two hand 

aspirated near the air line intake at the point and two using the through-theanalyzer procedure. Long term records of the closure between these two kinds of 

flask pairs should establish integrity of the air intake system data set. 

Surface Ozone: The Samoa ECC sensor was operational all year; however, 

difficulties were experienced with the Dasibi unit that required servicing off the 

island. Data from approximately 3 months of Dasibi operation are missing for the 

year, from early May until early August . 

Total Ozone (Dobson): Regular daily observations were maintained all year. 

CO2 Flask Sampling: Regular weekly samplings were maintained all year plus 

special extra samplings each week for air line checks. 

Halocarbon Sampling: A weekly sampling schedule was maintained all year. 

Cooperative Trace Gas Programs: 

monitoring equipment functioned all 

for monitoring CH., CO, and CO 2 was 

The Oregon Graduate Center (OGC) halocarbon 

year. In addition, a second gas chromatograph 

installed during September 1979. 

9 
Table 3. --Summary of sampling programs at Samoa in 1979 

Monitoring program 

Gases 

Carbon dioxide 

Surfa ce ozone 

Tot a l ozone 

Fluorocarbons 

Aerosols 

Condensation nu c lei 

Scattering properties 

(su rface air) 

Atmospheric t urbidity 

Solar r adiation 

Global s pectral irradiance 

Dire ct spectral irradiance 

~leteorol ogy 

Temperature (air) 

Tempera ture (soil) 

Temperature (dew point) 

Relative humi dity 

Wind (speed and direction) 

Press ur e 

Precipitation chemistry 

pH and conductivity 

Cooperative programs 

CH4 , CO, CO2 (OGC) 

Atmospheric Lifetime 

Experiment fluoro carbon 

program (OGC) 

Rain co llection (DOE/EML) 

Rain coll ection (EPA ) 

Instrwnent Sampling frequency 

URAS-2T NDIR analyzer Continuous 

Evacuated glass flasks Dis crete 

Electrochemical conc entration Continuous 

cell 

Dasibi ozone meter 

Dobson spectrophotometer #42 

Flask sampling 

G.E. CN counter 

Pollak CN counter 

4-wavelength nephelometer 

Volz sunphotometer 

4 Eppley pyranometers with 

quartz, GG22, OG1, RG8 

filters 

Eppley NIP with filter wheel 

(OG1, RG2, RG8) 

Eppley NIP/equatorial mount 

combination 

Thermistor 

Thermograph 

Psychrometer 

~lax. -min. thermometers 

Thermistor 

Thermistor with LiCl dew cell 

Hygrothermograph 

Bendix aerovane 

Transducer (capacitance type) 

~1icrobarograph 

Mercurial barometer 

Orion pH meter 

Beckman conductivity bridge 

Samples sent to MLO for further 

analysis on ion chromatograph 

Carle gas chromatograph 

H-P 5840A gas chromatograph 

Wet-dry collectors 

~1isco collector 

10 

Continuous 

Discrete 

1 wk- 1 

Continuous 

Discrete 

Continuous 

Discrete 

Continuous 

Discrete 

Continuous 

Continuous 

Continuous 

Discrete 

Discrete 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

Dis crete 

Dis cre te 

Discrete 

3 h- 1 

Discrete 

1 h- 1 

Continuous 

Continuous 
Aerosols 

The GtlCC GECNC functioned continuously all year except for a few minor 

breakdowns and repair-maintenance eqisodes. The Pollak functioned properly all 

year also. Major problems developed in the Samoa nephelometer unit, however, and 

it was returned to Boulder in January for checkout and repair. After its return 

in late March, its performance was somewhat better, but deterioration began again 

and a major problem seemed to involve the PM tube cooling system. Therefore, in 

September, the unit was again returned to the United States for modification so 

that PM tube cooling could be eliminated. The unit should be back in operation in 

1980. 

Solar Radiation 

GMCC sensors were online continuously all year. The NIP filter wheel was 

returned to Boulder in March to measure its transmission characteristics and 

returned after tests were comp l eted. GMCC solar radiation program traveling 

standards were received in June, and intercomparisons with SMO GMCC sensors were 

performed. Deterioration of filter domes for the Samoa pyranometers continues to 

be a problem, particularly for the RG8 and OG1 units. 

Meteorology Sensors 

The GMCC Aerovane transmitter synchro was replaced in October after it was 

discovered that the original synchro rotor winding was open. In consequence, wind 

direction signals intermittently differed by 1800 from true wind direction. 

Receipt of replacement bobbens for the LiCl dew cell was delayed, resulting in the 

sensor being offline from August until December, when spare bobbens finally 

arrived. 

Precipitation Collection 

DOE/EML wet-dry collectors: One of the two collectors failed during December. A 2-yr summary of the DOE/EML analysis of Samoa GMCC samples from the wetdry collectors was published during the year, coveri ng the period from April 1976 

through March 1978 (Bogen et a l ., 1980). 

2.4 South Pole 

2.4.1 Facilities 

The GMCC South Pole program continued operation for the 1979 season in the 

new Clean Air Facility (CAF) (diagrams in GMCC Summary Report 1978). No major 

modifications were made to the internal layout. 

The two transformers in the CAF that caused power problems in the previous 

season were replaced with one transformer large enough to handl e all CAF power 

r.equi rements without overheating. 

This year only three sampling stacks were used by the University of Maryland 

for the atmospheric chemistry program.. Since the stacks create a shadow on the 

solar radiation equipment, the unused ones were taken down this December. 

11 
This year the drifting downwind of the building is becoming very noticeable 

and may soon become a problem (see figs . 1 and 2) . The path leading from t he 

station to the stairs is exactly downwind of the stairs and is raised above the 

surrounding snow several feet, mainly because foot traffic packs s now too tightly 

to drift away. During the year the path has gained at least 6 ft in places . 

No problems were encountered with the building itself, and it continues to be 

an excellent location for the program. 

( 

I 

, , 

Figure 1.--Clean Air Facility at sPa. 

Photo was taken in January 1977. 

2 . 4.2 Programs 

Figure 2.--Clean Air Facility at SPO. 

Phot~ was taken in January 1981. 

SPO programs for 1979 are listed in table 4 and briefly described below. 

ICDAS 

The NOVA 1220 and all other ICDAS associated equipment ran continuously a ll 

year without failure . In January a new Wangco tape drive replaced the old one, 

which was stored in the CAF for the year as backup. A new Chronolog clock was 

shipped to sPa, but it had an improper ground connection. This was not discovered 

at the South Pole, and it was returned to Boulder. The old clock ran wel l a ll 

year so this created no problem. The only equipment malfunction was a loose 

attachment between the platen and paper roll on teleprinter, which was repaired 

with Permabond glue. 

Because of cracked batteries the uniterruptabl e power source was not used . 

Since the year had very minimal power downtime, this created no problem. 

Carbon Dioxide 

The URAS-2T was secured for t he year in mid-November 1978. The program 

consisted of exposing pairs of 0.5-~ glass flasks by hand, aspirating t hem on t he 

roof of the CAF. Samples were taken at the rate of one pair per week until 

March, then two pairs per week until November when the URAS was restarted. 

12 
Table 4 .--Summary of sampling programs at South Pole in 1979 

Nonitoring program 

Gases 

Ca rb on dioxide 

Surfa ce ozone 

Total ozone 

FI uoroca rbons 

Ae r osol s 

Condensation nuclei 

Optical prope r ties 

Solar rad iation 

Globa l spectral irradiance 

Direct spec tral irradiance 

et.eorology 

Air tempera ture 

Snow t empera ture 

Pressure 

Wind (speed a nd di r ection) 

At.mosphere moisture 

content 

~Iiscel aneous 

Room temperat.ure 

Coope r ati ve programs 

Carbon dioxide (SIO) 

Total sur face part iculates 

(atmosphere trace metals) 

(DOE/ERDA/HASL) 

Turb idit.y (NOAA/ ARL) 

Carbon- }4 sampli ng 

(NOAA/ARL) 

I onospheric opaci t y 

(Univ. o f Ca lif., Sa n 

Diego; NOAA/EDI S) 

Aerosol chemistry 

(CSRIO) 

Atmos pheric chemist ry 

(Univ. of Maryland and 

URI) 

Aeroso l concentration 

(Laborat.oire du 

GlaC i ology, Fr. ) 

Atmosphe ri c t.ritium 

(Un i v. o f ~Iiami, Fla. ) 

Individua l pa rti cle 

analysis (NOAA/APCL) 

Illstrument Sampling frequency Data 

£ evacuated glass flasks, 

han d aspirated 

Electrochemical concentration 

cell 

Dasibi ozone meter 

Dobson spec t ropho tometer 

300-ml st ainless steel 

sampling cylinders 

G.E. CN co unter 

Pollak eN coun t er 

Long tubed Gardner CN count.er 

4-1.'3velength nephelomete r 

4 Eppley pyranomet.ers with 

quartz, G6-22, OG-l, and 

RG-8 filt.ers 

Ultraviol et radi ometer 

NIP on meridional tracker 

filter wheel normal incidence 

pyrheliomet.er wit.h quartz, 

OG - l, RG - 2, RG-8 filters 

Thermistor (naturally ventilated shield) 

Thermistor 

Transduce r 

Bendix-Friez aerovane and 

re cording system 

Dupont 303 moisture monitor 

The rmistor 

5-£ evacuated glass flasks 

Motor driven rotary lobe 

blol.'er (high volume air 

sampling through filters) 

Dual wavelength sunphotometer 

Pressuri zed steel spheres 

30- and 50 -~rnz riometers 

Grid i mp actor 

Hi gh volume filters 

Coul ter coun t er 

Trit.i um traps 

Nuclepore filters 

13 

I pair I.'k- I 

2 pair .... 'k- I 

Continuous 

Continuous 

Discrete 

Ipairwk- I 

Continuous 

Discrete, 2-4 day I 

Discre t e, 1 day-l 

Cont.inuous 

Continuous during 

aust.ral summer 

Continuous during 

austral summe r 

Continuous during 

ausLral summe r 

Discrete during 

austral surruner 

Continuous 

Continuous 

Continuous 

Cont.inuous 

Continuous 

Continuous 

2 rna-I (3 fla sks 

per sample) 

Continuous (filters 

changed 4 times rna -I) 

Discrete during 

austral summer 

500 P.S.I . ambient air 

day-I, [or 6 days 

Continuous 

Continuolls 

Continuous 

I mo- l 

reco r d 

Dec 78-Ma r 79 

~la r 79-Nov 79 

Dec 71 -Jan 79 

J,n 76 -pre sent 

Dec 63-p resent 

J,n 77-Dec 78 

J,n 74-present 

Jan 74-present 

Jan 74 -present 

J,n 79 -present 

Feb 74 -pre sent 

Feb 74- present 

Oct 75 - present 

J,n 77 -present 

"" 77 -present 

Jul 77- pre sent 

Dec 75- present 

Dec 75- pre sent 

~Ia r 77 -pre sent 

Jul 78-p resent 

1957 -present 

May 70-present 

Jan 74-present 

Jan 74-present 

1974-Jan 80 

Jan 79-Ja n 80 

Jan 79 - present 

feb 79-Dec 79 

Jan 79 - Dec 79 

Jan 79 -Dec 79 
Surface Ozone 

The ECC and Dasibi 1326 were run until mid-January 1979. At that time a new 

modified Da sibi ( 1316) was sent to SPO. After numerous intercomparisons the old 

Dasibi and the ECC were retrograded to Boulder . The new instrument gave a very 

quiet signal and r a n well until Hay. A problem in the display board caused a 7 to 

appear in the display just l eft of the decimal point; this did not affect the 

output. The s olenoid began jamm ing, and the va l ve diaphragm was found to be very 

badly wo rn . The air pump bearings became worn and were shimmed but finally seized 

in July . A pump from a nother proj ect was patched into the system. Lamp cracking 

was a problem as in previous years, and after a power down in October the last 

good l amp crac ked . The output was so unstable that no amount of adjustment could 

give a signal. The new Dasibi was difficult to repair because it was a modified 

version, and most available spare parts fit only the older version. Even the 

spare so l enoid, a frequent source of breakdown, could not be used. 

Total Ozone 

The Dobson no . SO was operated all year without malfunction. Observations 

were made at approximate ly 2200, 0000, a nd 0200 CUT during t he austral summer. 

Moon observations were made when the disc was three-quarters full or fuller. Any 

blowing snow or thick ice ha ze made the signal too weak and noisy to get a usable 

tra ce from the moon. 

Ae rosols 

Aerosol observations were taken twice daily at approximately 1030 and 2230 to 

coordinate with the radiosonde balloon launches . Only routine maintenance was 

required for the Gardner a nd Pollak counters . In early August after routine 

cleaning and regreasing the GECNC background was offscale. A thorough overhaul 

only increased the background. Finally it was discovered that the positions of 

both the lamp and PM tube are extremely critical for a low background and an 

output in the proper range . Eventually all adjustments were made to minimize 

background. It wa s also noted that a very small change in vacuum causes large 

changes in output, which was useful in getting the signal into the proper range. 

The nephelomete r was run for the first year at SPO. 

minor breakdowns. Very strange variations in output and 

output were seen t hroughout t he year. The cause has not 

Meteorology 

It ran well with only 

occasional drops to zero 

yet been determined. 

Only minor problems were encountered in the electronics of the meteorology 

program. Loose connections and dirty contacts accounted for most of these. The 

pressure me asured by t he GMCC instrument was consistantly 2 . S mb lower than the 

station readout . Whenever winds we re calm, the ICDAS output for windspeed was 

1.19 m s-l. This may have been a ~nJX offset but was consistant all year. 

Solar Radiation 

Heavy icing of the pyranometers was still a problem, especially in the 

coldest part of summer shortly after sunrise. The only brea kdown all year was a 

burnt out bodine motor i n the equatorial tracker, which was replaced with a spare. 

14 
Halo carbons 

In the past the winter samples, which were stored over long periods, were 

found to give poor data . The schedule was modified this year so that only summer 

samples were taken , at the rate of one pair per week. The equipment ran perfectl y 

all year. 

2.4.3 Cooperative Programs 

Several cooperative programs were added this year (see table 4), which 

created no strain on the GMCC program or personnel. 

15 
3. CONTINUING G~ CC PROGRAMS 

3.1 Carbon Dioxide 

3.1 .1 Analyzer CO 2 Measurements 

CO 2 measurements made with continuously operating nondispersive infrared gas 

analyzers were continued during 1979 at BRW, MLO, and SMO. At SPO, where similar 

observations were discontinued in November 1978, the CO2 meas urement program was 

reinstate d in December 1979. 

Data acquisition and processing procedures remained identical in 1979 to 

t ho se employed previously (see mlcc Summary Reports 1977 a nd 1978 ) . Mean monthly 

CO 2 mole fractions were comput ed from edited hourly CO 2 va lues for BRW and MLO and 

added to the existing data for these stations as s hown in tables 5 and 6. Re s ults 

in these tables are expressed in the 1974 WMO CO 2 -in-air mol e frac tion sca le with 

tentative pressure broadening corrections applied. Plots of the data are shown in 

fig. 3. 

The data presented are preliminary since results from BRW have ye t to be 

updated by using improved working reference gas concentration va lues ; also, pressure broadening corrections applied to both the BRW and MLO data are tentative. 

Relative errors in the plotted data are estimated to be 1 ppm for BRW a nd < 0 .5 

ppm for MLO. Systematic errors for both data sets are believed to be less than 

±1 ppm when referred to an absolute CO2 mole fraction calibration sca l e. 

CO2 analyzer data for SMO are not presented in this report since an air 

intake line problem affecting data quality is being investigated. Final data 

processing ha s been postponed until recent t est data are eva luated and pressure 

broadening corrections are determined for t he URAS-2T (no. 016) CO 2 analyzer in 

use at StIO . 

3 .1 .2 Fla sk Sample CO 2 Measurements 

The NOAA Environmental Research Laboratories CO 2 f l as k sampling program dates 

from 1968 when the Atmospheric Physics and Chemistry Laboratory began to measure 

CO2 at Niwot Ridge near Boulder, Co lo., and a t Ocean Station Cha rlie in the North 

Atlanti c . When Air Resources Laboratories GMCC program was formed in 1971, CO 2 

flask sampling was gradually expanded to include air sample collections at the 

350 

345 

340 

E 

~ 

~ 

E 335 

a 

" 330 

325 

320 

1973 

--BAW 

--MLO 

, p.,. \ ~. ~ 't' \ , , . ' -, 

1974 1975 1977 1978 1979 

16 

Figure 3. - -Mean monthly CO2 mole 

fractions for Barrow (solid line) 

and Mauna Loa (dashed line) plotted in the 1974 WMO mole fraction CO 2-in-air scale. 
Table 5.--Barrow Observatory monthly mean CO 2 mole fractions''; 

Honth 1973 1974 1975 19 76 1977 1978 1979 

Jan 339. 11 338 . 50 33 7. 56 336.68 339.38 339.35 

Feb 336.82 338.73 337.80 336.90 340.24 340.59 

Har 337.57 338 . 22 338.77 338.19 341.73 341. 65 

Apr 338.87 338.53 338 . 90 339.09 34 1. 06 341.43 

May 337.35 339 . 62 338.24 339.25 340.83 34 1. 90 

Jun 336.40 336.07 337.12 337.78 339.57 340 .94 

Jul 324.44 33 1. 00 329 . 94 331 . 26 330.14 332.02 332 . 61 

Aug 322.69 325.52 324 .74 323.78 326.79 328.29 327.60 

Sep 325.68 326.38 325 .78 325.09 328.04 328.62 329.55 

Oct 330.29 330.06 330.20 330 .06 332 .17 332 .20 332.54 

Nov 334.07 333.27 335.32 334 .1 7 334.92 338.12 337.71 

Dec 334.48 336.65 337.0 1 336 .46 338.78 338.60 340 . 98 

-I·Values expressed in ppm 1974 ~IO CO 2-in-air mole fraction scale. 

GHCC stations at BRW, SMO, SPO, MLO, and two other sites, Key Biscayne, Fla., and 

Cape Kumakahi, Hawaii. 

Because of the i mportance of the CO2 problem to U.S. energy policy requirements, a program was started in 1978 in the Office of the Assistant Secretary for 

Environment, DOE, with the goal of developing the ability to predict future environmental , agricultural, and social consequences of increasing atmospheric CO 2 

concentrations. This multifaceted national research and assessment effort include s deve l oping and validating a gl obal carbon cycle model for use in forecasting future CO 2 growth. Among required inputs to the model are CO 2 me asurement 

data from an expanded network of stations that can provide information on globally 

averaged CO 2 trends, global CO 2 gradients, global as well as temporal CO 2 annualcyc l e amplitude variations, and CO2 sources and sinks . 

Table 6.--Hauna Loa Observatory monthly mean CO 2 mole fractions''; 

~Ionth 1974 1975 1976 1977 1978 1979 

Jan 330.45 33 1. 58 332.73 335.06 336.03 

Feb 33 1. 21 332.54 333. 13 335 . 28 336.45 

Har 33 1. 86 333.27 334.70 336.36 337 . 85 

Apr 330.00 334.59 335.93 337.75 338.46 

Hay 332.89 333.60 334.82 336.60 337.91 338.98 

Jun 33 1. 79 333.04 334.24 336.00 337.87 339.11 

Jul 330.51 331.29 332.52 334.35 336.72 337.37 

Aug 328.48 329.43 330. 31 332.30 334.18 335.16 

Sep 326.92 328.09 328.84 331 .08 331.99 333.79 

Oct 326.77 328.43 328 . 63 331 .24 332.36 334.26 

Nov 327.97 329 . 37 329.92 332.56 333.65 335.05 

Dec 329.31 330.69 330.40 333.86 334.77 336.41 

''''"Values expressed in ppm 1974 WIlO CO2 -in-air mole fr·action scale. 

17 
''0 ''0 , .. "0 

off1O fI I I 

10 " 0 

I 10 0 10 

-'o.d I)>> \J.../ December 

'-

31 . 1979 

• 17 operaling stations 

... 6 stations to be activated 

X I discontinued station 

I I I I I , 10 10 

'" 00 

-

, 

00 

Figure 4.--Map showing the global distribution of existing, planned, and defunct 

NOAA and cooperative CO 2 sampling stations on 31 December 1979 . 

To obtain the needed data, the GMCC program with financial support from DOE 

began expanding in 1978 its eight-station CO2 network to 23 stations (fig. 4 and 

table 7). CO 2 sampl es are periodically collected at the sites and forwarded to 

the GMCC l aboratory in Boulder for analysis. One aim of the program is to identify stations where high quality global background data are obtainable, with a 

view of upgrading the CO 2 monitoring at these sites with continuously operating 

CO 2 analyzers. 

Air is collected at the stations in paired 0.5-£ glass flasks. All sample 

analyses have been performed at GMCC Boulder using Mines Safety Appliance Company 

(MSA) infrared CO 2 analyzers (type 200, SIN 1809 before 5 April 1975, and type 

202, SIN 20719), except that an H. Haihak Company UNOR-2 (SIN 631521) instrument 

was used to analyze air sampl es collected during 1979 at Amsterdam Island, Indian 

Ocean , and Palmer Station, Antarctica. Air samples from the flasks were transferred into the MSA ana l yzers by using a mercury displacement pump (Bischof, 

1975). Samples were analyzed with the UNOR-2 instrument on a newly developed 

semi-automatic apparatus (Komhyr et al., 1979) that has a displacement pump made 

18 
Ta bl e 7. --C02 fl as k samp l Ing Sl a llon sLl_a y 

Slal i o n 

'"0 

Ams t erda lll Is. , ILHI , an 

Ocean 

SPO 

Ascens Io n Is. , South 

Atl antI c 

Azo r es (Te r ce. r a Is.) , 

N. At la nti c 

Cape Kumakah i. Hawa I , 

Co ld Bay, ,\la s ka 

Cosmos 

Ea ste r Is ., South 

Pa c ific 

f a lkl and Is. 

Galapagos (C hathallL 

Is. )' South Pact f ic 

Guam ( Hariana s I s .) , 

N. Pacifi c 

Key Bi scayne , Pia . 

tbuna l oa . Hawa i. I 

Hauna Ke a , Ha.:a i i 

l1 0u l d Ba y , N."'.T . 

Niwo t R.dge, Co l o . 

Ocean SUlion Cha rli e 

(U.S. ) 

Ocean S tat i oo H 

Pal. er Sta t i o n 

(Anvers Is . ) 

Po int Ba~ ow, Ala s ka 

Point Six Mo unlain, 

NonL 

Seychelles (Mahe 15.) , 

Indian Ocean 

St. Ccoix, Virgin 

Is la l1 ds 

----------------- Counl y 

U.S. t erritory 

France 

Ant .. rct ica 

U. K. 

Port ugal 

u S. 

U S. 

I'e ru 

Ch, Ie 

U.K. 

Equador 

lH./long. 

]4°]5'5 , 170°34' 1.1 

)7°52'5 , ]1°32'E 

89°59'5 , 24°48' .... 

7°55'5 , 14°25'''' 

Elevat , on Cooperat.nl! ag .. ncy 

,oj 

)0 (GMCC statlon) 

]50? Centre <il'S Llib]es 

Rad,oact,v,l,es 

2.810 (G'1Ce station) 

54 USAf/PaIL ""'e~lc;1Il 

""orl<l A,n'ays 

)O? U.S. Dept Air Fo~ce 

7th "'eathe~ IOIIlg 

(G:1Ce s , te) 

55 0 I 2' N, 162°43'1.1 25 NOAA, N ... ·S 

12°07'S , 75°20· ... ' 4 ,600 Inst l tuto Geof,sico 

<Ie Peru 

200 1-hnistro de De f ensa 

Io .. cional D,reccion 

l1eleOrololl,ca de CI .. le 

';1 IIrllLSh Ml'tL'"oro\ogical 

Serv,cl' 

6 InSt l tLltO "alional de 

l'ietl'oro l ogu e 

Hidrologu 

Period of record 

Jan 1972 t o p r esent 

Jan 1919 t o p r esel1 t 

Jan 1975 to p r esen t 

Aug 1979 to p r nent 

Dec 1979 to present 

Har 1976 to p r esen t 

Oct 1978 t o p r esen t 

Sel' 1979 t o p r ese nt 

(PrograllL t o begin 

In 1981) 

(PrograllL to begin 

In 1980) 

(Prog r a .. to begin 

In 1981) 

Site t ype 

Is land r oc ky promo nto ry 

Is 13l1d seas ho r e 

Icl' £; snow cove r ed pla t eau 

Isl and sl'",s hore 

Isl and 51'uho r e 

Island s e as ho r e 

Treel ess pen i ns ula 

Alpine LIIo unta i n 

Island s e u ho r e bluff 

Island seas ho r e 

Island seas ho r e 

U.S. t er rito ry 1) °26' N, 144°47' E Un,ve~s'ty of Guam M~r 1979 to p rl'sent Is land s e as ho r e 

u.s. 

u.s. 

u.s. 

Cana da 

US. 

N. Atla nt i c 

N. At lant ic 

Antarc ti ca 

US. 

U.S. 

Seychel les 

25°40' N, 80°10'1.1 SOM , Sea - Air Inte~­

actIon laboratory 

Dec 1972 to Har 197 4 Coa s tal IS land s eaHa r 1976 t o pr esent e 

19°32' 1' , 155°3S'"" 3,397 (GMCe statIon) 

19°50' S . I SS028 ' ''' 4,220 Institute for Astron -

omy, L:niv of Ha"all 

Jun 1976 to present 

Jan 1979 to presen t 

Ba rre n, vo l cani c LIIountain 

s l ope 

Al p i ne .ount3l n pe", 1< 

76°14' S , 119°20'\" IS Dept. of EnvI~onmen , (Program to beg in in I s land tund ra 

AtJJlosphl'ric Environ- 1'180) 

.. ent Sl'~v,cf' 

40003 'S, 105°38''''' 3,749 I NSTMR , Un.v. of Feb 1968 to Jan 197 4 Alp i ne mo unta i n 

Colorat.lo Jan 1916 t o p resen t 

54"00' S, 3S000·.... 6 NOM , 1'\,'5 Nov 1968 t o Nay 19 73 Open ocean 

S4°00' N, 3S000''''' 6 or"'egi~n l1eLeoro10g- (Prog r a. to beg i n Ope n ocean 

ical Inslltut e In 198 1 

64°SS'S, 64°00'.... 10? Desert Rl'search Lab. Feb 1978 to present 8arren i.s land seuhore 

lnlv. of "evaoda 

71° 19' 1' , IS6°36'\, 11 (G!1eC sta l lon) Apr 1971 to presen t Arc tI C coastal sea s ho re 

47°02' N, 113°59' 1.1 2 , 462 U.S. Nl.'S Hay 1978 to present .... ooded mounta, n t o p 

5°20 ' 5 , 5So 10'E 31 Phys i cal SC"le n{"e !.ab. , (Program to bl' g i n Island s eas ho r e 

Se,,' Hl'xico S t a Le Uni v . In 1980) 

fa. ri eigh Dick,nson 

U,\lV. 

Ha~ 1979 t o I'resen t Isl and seasho r e 

up of a glass cylinder with a free-floating piston fabricated from Teflon reinforced with glass fibers. Additional details concerning sampl e collection and 

analysis procedures are given in Komhyr and Harris (1976) 

Before 31 December 1978 all samples were analyzed using CO 2-in-N2 reference 

gases calibrated by the Scripps Institution of Oceanography (SIO). Beginning with 

air samples collected in 1979 and including samples collected at Palmer and South 

Pole stations during 1978, analyses were performed us ing CO 2-in-air reference 

gases, also calibrated by SIO. The carrier gas was changed from N2 to air to 

eliminate the need to apply data corrections arising from differences in 4.3-~m 

infrared radiation absorption characteristics of CO 2-in-N2 as opposed to CO 2-inair. 

The CO 2-in-air reference gases used in analyzing mo st 1979 air samples were 

obtained during April and May 1977 by pumping air to a pressure of 150 atm into 

large, chrome-molybdenum steel tanks fitted with noncontaminating bellows valves . 

19 
(. J ~~ 

· . 

20 
Air was collected at the University of Colorado Alpine Research Station CI site, 

in the mountains west of Boulder at 3-m elevation. Pumping was performed only 

during clean air, downslope wind conditions at times when Aitken nuclei counts 

were less than 6,000 cm- 3 and occasionally below 1,000 cm- 3 . The air compressor 

used was a noncontaminating, three-stage, RIX Industries model 153B-3 piston 

cylinder pump fitted with reinforced TFE Teflon piston rings that enable the unit 

to operate without lubrication. Type 3A molecular sieve material was used with 

the pump to dry the compressed air to a dew point temperature of about -70°C . 

Tank CO2 concentrations were adj usted by either partial removal of CO 2 from the 

pumped air with a type 13X molecular sieve material, or by adding small quantities 

of 99.99% purity CO 2 to the pumped air. 

CO2 -in-air reference gases used with the semi-automatic analysis apparatus 

were procured from Liquid Carbonic Corporation, Los Angeles, Calif. They are 

comprised of CO 2 in dry (dew point less than -73°C) synthetic air containing 

natural proportions of nitrogen, oxygen, and argon. High purity nitrogen and 

argon are used to prepare the carrier gas together with oxygen derived from e lectrolysis of water. Intercalibration of these synthetically produced gases with 

natural air reference gases indicated that both types are equally suitable for 

calibrating nondispersive infrared CO 2 analyzers. 

Individual CO 2 flask sample ana lysis data, for samples collected during 1979 

at 15 stations, are plotted in fig. 5. Results are expressed in SIO 1974 provisional CO2 -in-air mole fraction scale. Smooth hand drawn curves fitted to the 

data plots are provisionally assumed to be representative of background CO 2 data 

at the stations. 

In a preliminary attempt to improve data quality through data selection, 

visible outliers in fig. 5 have been identified as representing unreliable da ta . 

Such data are shown enclosed in brackets. Two groups of Palmer Station data 

(circled in fig. 5) are also taken to be unreliable, even though they may be 

representative of some local source of CO 2 , Measurements made at that site in 

1980 may shed light on this apparent data anomaly. 

Mean monthly, seasonal, and annual CO 2 mole fractions for 14 of 15 CO 2 flask 

sampling stations are listed in table 8. The values have been derived by averaging sample data plotted in fig. 5, excluding br~cketed data. In a few instances 

where measurements were not made, or the measurement data were deemed unreliable, 

the monthly means were inferred from the hand drawn curves in fig. 5. Such values 

are shown enclosed in parentheses in table 8. 

Seasonal and annual CO 2 mole fractions plotted vs. latitude are shown in 

fig. 6. (Data for Amsterdam Island and Palmer Station are not included in the 

plots since an adjustment to the data from these stations may be necessary.) The 

seasonal uptake of CO2 by vegetation in the Northern Hemisphere is clearly evident 

in the plots. In fig. 7, peak-to-peak CO 2 annual cyc le amplitudes are plotted as 

a function of latitude. A maximum CO 2 amplitude of 17.4 pmm peak to peak is observed at Cold Bay, Alaska, whereas a minimum va lue of 1.4 ppm peak to peak occurred at Samoa . Corresponding data for other stations are provided in table 9 . 

The results discussed above are tentative. A more definitive study of these 

data is in progress. 

21 
Tab l e 8 --Hean CO2 mole fraction!" In PPII'" 

Honth 

J .. 

F,b 

H" 

Ap' 

Hay 

J un 

A". 

S'P 

0" N,. 

Do< 

J - f - H 

A-tl-J 

J-A- S 

O-N -D 

Annual 

DRW 

340.8 

341.5 

342.0 

342.8 

343.0 

341.1 

332.5 

326.9 

329.0 

333.3 

337.5 

341.2 

341.4 

342.5 

329.5 

337 . 3 

337.1 

eSA 

340.4 

34 1. 2 

342. I 

343.0 

342.9 

339.2 

332.3 

325.8 

330.5 

331.2 

)40.6 

342.0 

341.2 

341.7 

329.5 

339.9 

338.0 

PSH 

340.0 

340.3 

)40.5 

)40.3 

338.9 

335.5 

330.0 

321.2 

329.9 

335.0 

337.5 

339.2 

340.3 

338.2 

329.0 

337. 2 

336.2 

'"'Values derived from plots ,n f ig. 5. 

338.7 

339.9 

340.6 

34\.0 

34\.0 

338.4 

335.0 

332.5 

332.2 

334.0 

336.2 

339.0 

339.7 

340.1 

333.2 

336.4 

337.4 

KEY 

340.0 

340.7 

341.2 

3f. I.4 

341.0 

339.7 

336.9 

334.5 

334.0 

3)5.6 

331.8 

340.0 

340.6 

340.7 

335. I 

331. 8 

338.6 

HLO 

336.7 

336.9 

339. I 

338.9 

339.0 

339.3 

337.7 

335.8 

333.9 

333.9 

335.7 

336.8 

331.6 

339.1 

335.8 

335.5 

337.0 

Stalion 

HKO KUH 

336.8 

337.9 

339.5 

340.5 

339.9 

340.4 

338.0 

335.1 

334.8 

335.7 

337.3 

339.1 

337.8 

340.3 

336.2 

337.4 

337.9 

336. \ 

339.3 

34\.2 

339.8 

341.3 

340. \ 

336.0 

333.2 

332.1 

334.0 

336.8 

338.\ 

338.9 

340.4 

334.0 

336.3 

337.4 

AVI 

(338.7) 

339.7 

340.3 

340.8 

340.5 

338.5 

334.4 

333.0 

333.5 

335.0 

336.9 

338.5 

039.6) 

339.9 

333.6 

336.8 

031.5) 

GM! 

(337.8) 

(338.3) 

339.0 

339.5 

340. I 

340.0 

338. I 

336.4 

335.5 

335.6 

336.8 

339. I 

(338.4) 

339.9 

336.7 

337.2 

(338.0) 

Table 9.--Peak-to-peak amplitudes of CO 2 annual cycles * 

Station ppm/max. ppm/min. 

BRW 

CBA 

PSM 

NWR 

KEY 

MXO 

MLO 

KUM 

AVI 

GMI 

SMO 

AMS 

PSA 

SPO 

343.3 

343.3 

340.6 

341.2 

341.3 

340.7 

339.8 

341.7 

340.7 

340.2 

336.7 

339.2 

339.0 

337.2 

*Data extracted from plots of fig. 5. 

22 

326.9 

325.9 

327.5 

332.0 

340.0 

334.7 

333.5 

332.8 

333.0 

335.4 

335.4 

337.5 

337.0 

335.3 

SMa 

335.\ 

335.2 

335.5 

335.6 

335.8 

336.0 

336.0 

336.\ 

336.2 

336.2 

336.2 

336.3 

335.3 

335.8 

336. \ 

336.2 

335.8 

AMS 

338.0 

337. 2 

331. 3 

338.3 

338.7 

339.5 

339.0 

338. I 

338.2 

340.0 

339.0 

338.1 

337.5 

338.9 

338.4 

339.3 

338.5 

PSA 

337.0 

336.9 

337.2 

336.1 

037.3) 

(337.8) 

038.2) 

339.0 

(339 .0) 

039. I) 

(339.0) 

338.9 

337.0 

037 . 3) 

(J38 . 7) 

(339 .0) 

(338.0) 

amp!. (ppm) 

16.4 

17.4 

13.1 

9.2 

7.2 

6.0 

6.3 

8.9 

7.7 

4.8 

1.4 

1.7 

2.0 

1.9 

SPO 

335.8 

335.5 

335.3 

335.3 

335.5 

336.0 

336.3 

336.9 

336.9 

337. I 

)37.0 

037.0) 

335.5 

3)5.6 

3)6.7 

337.0 

(]36.2) 
341 

E 339 ~ 

~ 

....... AMJ 

!~.~ .. " ·JFM 

r j '-;'-:-":-.., ..... J 

I :\.,: . \ I/,-. ANNUAL I . \ I· \ / .. "" V/ \ c /'''f'..} I 337 :'::::-':":=:-~..:.::::-..;.=:-. < ~:::~; V· . . OND 

':; ~.~.=.-::c.:::~. ................. . \ 

~ 335 1/'\ 

()3 333 \ 

o -::b- ~« ~ ~::Jw Iv> OJ (/) (!) ~:lo:: a. 0 

I I~I I I I 331 SPO 

" '" OJ 

I 

329 I I '" " Z V JAS 

90S 80 70605040302010 0 1020304050 60 70 8090N 

Latitude In Degrees 

Figure 6.--1979 seasonal and annual 

meridional distributions of CO2 , 

~ 

i 16 () 

~ 14 c 

c 

'" , 12 

8 

a 10 

• 

~ • 

~ 8 

~ 6 ~ 

• 8' 4 

~ x 2 SPO PSA 

:f 

KUM 

AMS 

SMO 

o I I 

KEY 

90S 807060 50 403020100 1020 30405060 70 8090N 

latilude In Degrees 

Figure 7.--Meridiona l distribution of 

peak-to-peak CO2 annual cyc l e amplitudes. 

3.2 Total Ozone 

3.2 . 1 Observations of Total Ozone 

Total ozone observations were continued throughout 1979 at 11 of 12 stations 

listed in t able 10 . In May 1979, the Department of Meteorology at Florida State 

University, Tallahassee, notified NOAA that it would no longer fund the total 

ozone program, and that observations would be terminated at the end of May 1979. 

Plans are unde r way to re-establish the program either in Tallahassee at the NWS 

sit e or at some other l ocation i n southeastern United States. 

During June , July, and August 1979, world standard Dobson ozone spectrophotometer no. 83 wa s operated at MLO to check its calibration. The data obtained, 

together with similar data from past years, will be analyzed to determine whethe r 

solar constant variations at the Dobson instrument wavelengths occur during the 

cours e of a so l ar (sunspot) cycle . 

3.2.2 Modernization and Calibration of Dobson Spectrophotometers 

Under auspices of the WHO Global Ozone Research and Monitoring Proj ect, three 

foreign Dobson spectrophotometers were modernized, optically a l igned, and calibrated : no. 74, Hradec Kralove , Czechoslovakia; no . 110, Budapest, Hungary; and 

no . 121, Bucuresti, Romania. 

New U.S. designed electronic systems that use solid state circuitry and 

e le ctro-mechani ca l phase sensitive signal rectifiers were installed into the 

instruments. The instruments were then calibrated by comparison with European 

regiona l standard Dob son spectrophotometer no. 64, maintained by the German Democratic Republic (GDR) . Calibration of instrument no . 64 is traceable to U.S. 

st andard Dobson instrument no. 83. 

The instrument calibrations were performed in Potsdam, GDR, in J uly 1979, at 

international comparisons sponsored by WHO; pa rticipants are liste d in table 11 . 

23 
3 . 2 . 3 Data Analyses and Related Research 

The quality of total ozone data obtained by NOAA (and it predecessors ESSA 

and the National Weather Bureau) from the early 1960' s continued to be assessed. 

Research into the overall accuracy of Dobson spectrophotometer ozone measurements 

indicated that a systematic error of about 5% may be ass oc iated with Dobson 

instrument readings (Komhyr, 1980). The error is postulated to stem from use of 

an erroneous Dobson instrument s hort A wavelength absorption coefficient. This 

research has received considerable interest, and several investigators are examining the problem. 

A related investigation concerning the accuracy of Dobson spectrophotometer 

ozone observations revealed that S02 and N0 2 can potentially interfere with ozone 

measurements since they possess absorption spectra at the Dobson instrument 

wavelengths (Komhyr and Evans, 1980). In cases of extreme pollution, total ozone 

measurement errors are estimated to approach 25% because of S02 interference and 

5% because of N0 2 interference . A number of other constituents of polluted air 

(i.e., N20 s , H2 02 , HN0 3 , acetaldehyde, acetone, and acrolein) have been identified 

as having absorption spectra at the Dobson instrument wavelengths . Because the 

absorption coefficients of these trace gas pollutants are small, however, their 

total contribution to errors in ozone data is negligible. 

3.2 .4 The Data 

Daily 1979 total ozone amounts (applicable to local apparent noon at each 

st ation) for all stations i n the U.S. network have been submitted for publi cation 

on behalf of WHO and are available in Ozone Data for the World, published by the 

World Ozone Data Center. Mean monthly total ozone values for NOAA observatories 

and cooperative stations are presented in table 12. 

Table 10.- - 19 79 U.S. Dobson ozone pe t~ photomeler stalion ne t .... 'ork 

Station Period of record Instrument no. Age ncy 

Bismarck, N. Dak. 010163 present 33 NOM 

Caribou, Maine 010163 prese nt 34 NOAA 

Tutuila Is . . Samoa 121975 present 42 NOM 

TaLlahassee, Fla . 060273 053 179 58 NOAA / FIa. State Univ. 

tlauna Loa, Hawaii 010264 p resent 63 NOAA 

Wallops ". V •. 070167 present 72& 38 NOAA / NA SA 

Barrow I Ala ska 080273 present 76 NOM 

Nashville, Tenn . 010163 present 79 NOAA 

Boulder. Colo. 090166 present 82 , 83, & 38 NOAA 

In'hi te Sa nd s, N. Hex. 010572 present 86 NOAA/ Dept. o f Army 

Huancayo, Peru 021464 present 87 NOAA/Huancayo Obs . 

Amundsen-Scot t, Antarctica 120563 present 80 NOM 

24 
Table 11.--Participants in the Potsdam international Dobson spectrophotometer 

comparisons 

Country Inst. No . Participants 

German Democrati c Republi c 64 A. Bohme, K. Grasnick, 

P. Plessing, and U. Feister 

Czechoslovakia 74 J. Pi cha, Cenok 

Hungary 110 F. tliskolci, A. Sebestyen 

Romania 121 N. Frimescu 

Poland 84 A. Losiowa, N. Degorska, and 

B. Rajewska-Wiech 

German Federal Republic 44 H. Neuhoff, G. Pereira Brose 

France 11 A. Louisa, G. Armand 

Canada A. Asbridge 

United States R. D. Grass 

United Kingdom C. D. Walshaw 

Tabl e 12. --1979 provisional mean monthly total ozone amounts (milli-atm- cm) 

Location J,n reb tla r Apr M, y Jun Jul Aug Sep Oct Nov 

Bismar ck, N. Dak. 380 396 396 398 385 342 329 309 297 303 330 

Caribou, Haine 381 430 415 435 375 363 353 335 3 14 311 347 

Tutuila Is .• Samoa 256 254 251 256 262 261 259 261 267 270 260 

Tallaha ssee, Fla. 298 308 330 33 1 344 

Mauna Loa, Hawaii 262 262 282 299 296 285 217 274 269 258 258 

Barrow, Alaska 448 450 415 376 334 306 327 

Wall ops h . • Va . 350 355 372 380 355 341 329 317 292 297 282 

Nashvi lle. Tenn. 343 344 383 383 375 348 317 315 298 

Boulder, Colo. 352 368 375 382 361 323 320 307 295 286 3 12 

White Sa nds, N. Hex. 320 330 336 357 349 318 309 309 297 289 290 

Huancayo, Peru 259 258 259 261 262 264 268 269 275 267 271 

Amundsen-Scott, Antarctica 304 284 289 348 

25 

nec 

3 10 

364 

265 

244 

307 

3 11 

293 

288 

267 

351 
3.3 Ozone Vertical Distribution 

3.3.1 Operations 

Since February 1978, regular measurements of atmospheric ozone vertical distribution have been made at Boulder, Colo., using the Umkehr technique (see figs. 

8 and 9). Observations are made with a Dobson spectrophotometer , which measures, 

at large solar zenith angles, the ratio of intensities of scattered light from the 

zenith sky at two wavelengths in the Huggins ozone absorption bands. The manner 

in which this light intensity ratio varies with zenith angle depends on the ozone 

vertical distribution, which can therefore be deduced (see Craig, 1965). Mateer 

et al. (1980) recently described and tested a short Umkehr technique that utilizes 

Sun angle and wavelength variations, considerably shortening the observation time. 

Observations of the Umkehr effect at Boulder, Colo., have been made using 

three standard Dobson spectrophotometer wavelength pairs: A, C, and D. Although 

the ozone vertical profile data presented here were obtained by using the standard 

evaluation technique (Mateer and Dutsch, 1964) in use at the World Ozone Data 

Center, Toronto, Canada, the observations on three different wavelength pairs will 

allow recomputation using the short Umkehr evaluation technique. Umkehr observations and ozone vertical profiles derived from the observations are published by 

the World Ozone Data Center, Toronto. 

In addition to regular Umkehr observations, a series of simultaneous ozonesonde and Umkehr measurements was made. The primary purpose of this simultaneous 

set of measurements was to help provide a data base for use in developing the 

short Umkehr method. The balloon-borne ozonesondes provided in situ verification 

of results obtained by the remote Umkehr technique. 

3.3.2 Data Analysis 

Figure 8 gives mean monthly ozone amounts deduced in Boulder from Umkehr 

observations in each of nine atmospheric layers, beginning in February 1978. 

Pressure ranges for each layer are indicated in the plots. Except for the first 

few months of the program when observations were relatively sparse, the monthly 

means have been derived from three to eight observations per month. 

An example of a comparison of ozone profiles obtained by the standard Umkehr 

evaluation technique and a simultaneous balloon-borne electrochemical concentration cell (ECC) ozonesonde measurement is shown in fig. 9. 

3.4 Surface Ozone 

3.4.1 Operations 

Surfa ce ozone measurements were made using the Dasibi ozone photometer at the 

four GMCC baseline observatories. In addition, the ECC meter was used to make 

concurrent " mea surements with the photometer at Mauna Loa and Samoa and, through 

June, at Barrow. Because of problems with the Dasibi ozone photometer at Samoa 

during much of the year, most data obtained there came from the ECC meter. 

3.4.2 Data Analysis 

GMCC Summary Report 1978 (Mendonca, 1979) describes several important variations in surface ozone found at the G~ICC baseline observatories. At Mauna Loa , 

26 
Boulder, Colorado 

':r A-

:; r---

::} 

1. 96 - 0.98 mb 

3.9 - 1.96 mb 

7.8 - 3 9mb 

~ 100

-g 75 1 c 

'" c 

v 

'; 

~ 

~ 

~ 

"-

~ 

"-'" 

~ 100 o 

N 

o 

100 

75 

50 

75 

50 

Number of 

Observations 

~---

15.6 - 7.8 mb 

"'-/ ---

3 1.2 - 15.6 mb 

, __ - 62.5 - 31.2 mb 

~--- 125 - 62.5 mb 

500 - 250 mb 

1130535548527 

] 

383510658 

400r----------------------------------------------------, x 

5 350 A-__ Total Ozone 

x 

o Umkehr Days 

)( All Days 

, 

E 

;;; 

E 300 

250 ~7-~ -L~-L~~~~~~~-L~-L~~--L-L-~~~-L-" 

o J F M A M J J A S ON 0 J F M A M J J A S ON 0 

I 1978 I 1979 I 

Figure 8.--Umkehr observation mean monthly ozone partial pressures as a function 

of altitude at Boulder, Colo. 

27 
• .. 

o Z 0 NAG R A~ 

DATE' 

STATl!»!, 

09/2B179 

ID.l..OCRI1SI1 TOm.. OZONE' 293. ~ 

I NT(I;RATl:0 OZI»IE, 27B. 

T1t£. 183l CUT 

WlIPI£NT' = IBJ2 RESIIJ..f\L OZI»IE, IS. 

10 

4S 

", 

_ .-_ .. _- J 

20

0

0

~-" 

5 

'--- ·--- JO 

!Q..ao 

-- ~ "._.- - 2U '. .... 

--.......... '" 

v, 

'::::.':':-- SO t.J 

'-

~ 

'" 

Joo 

~ 

- ""-....- "'l=----If----. -_.---. /.00 

-'. 

""--d-----jSOO 

· 1 .2 

IC» 150 laD ZiO 

'-':Cc---':=---':::---">.-':::---';:-- ~I:;':Jpo" " '---I J 000 

-80 -60 -iQ - 20 0 20 10 

PART I fl. PRESSlJI[ or IlZOI£ I "00II J T!1t'!J<f11URE ,'tJ 

Figure 9.--Exampl e of simultaneous ozonesonde and Umke hr observations made at 

Boulder, Colo . 

for example, there is a strong diurnal variation in surface ozone associated with 

the mountain wind circulation . The downslope wind regime, beginning i n the evening 

and continuing into the following morning, b rings air from the region of the 

tropospher e above the observato ry. This air should generally be representative of 

the ozone content of the free troposphere. During the day, air reaches the 

observatory from below after pa ssing ove r vegetated areas at lower altitudes. On 

the average, the range of this variation is about 15% to 20% of the me an concentration, with t he l arger values occurring during the downslope wind regime . To 

check whether the upslope and downsl ope wind regimes represent different large 

scale processes in determining the ozone distribution, the annual variation was 

studied for the two regimes separate l y. The downslope regime was represented by 

da ily ozone maximum values, whereas up slope flow was rep resented by daily ozone 

minimum values . As seen in fig. 10, the behaviors of the seasonal variation for 

these two regimes are similar on the average. This indicates that the large 

scale influences on tropospheric ozone are similar throughout the troposphere at 

Mauna Loa. 

The importance of de t ermining the r epre sentativeness of s urface ozone for 

understanding tropospheric ozone behavior can be seen by comparing surface data 

28 
50 

"§' 

.2 40 0 

c 

m 

.s 

~ 30 0 

0 

0 

~ 

a: 

" 20 z 

~ 

"-

~ 

c 

0 10 N 

0 

0 

J 

Mauna Loa (19.5° N ) 

Monthly Means Derived 

From Daily Maximums 

Monthly Means Oeri ved ~~ _ ____ -

From Daily M inimums 

F M A M J JA S O N D 

Figure 10 .--Monthly mean maximum and 

minimum surface ozone partial pressure 

at MLO derived from observations of 

daily ozone maximum and minimum values. 

150 

140 

130 

120 

90 ~ 

.2 80 o 

c 

~ 70 

~ 60 o 

~ 30} 

~ 20} 

200mb 

500 mb 

a... 40 700 mb 

Resolute (1 968 - 78) 

~ ~ 30 t __ ~ __ ~~~~--~~--~ ~--~~ 

o 20 

30} 1000 mb l 

201 ~~~---o...o -....,...- I 0L-------------------------------~ 

40 Barrow (1973 - 79) 

30 ,"- 0-",,- Surface 

20 

10LL--~~~L-~~--~_7~~~ J F M A M J J A S ON ~~~ D 

Figure 11.-- Monthly ozone partial pressures at various levels in the troposphere at Resolute, NWT, compared with 

surface ozone at BRW. 

from Barrow with data from ozonesondes at Resolute, Northwest Territory. The 

average monthly ozone behavior at Resolute as a function of altitude for the 

period 1966 to 1978 is shown in fig. 11 . The average Barrow monthly surface ozone 

variation for 1973 to 1979 (see fig. 11) closely parallels that at 1,000 mb at 

Re so lute . But at higher levels in the troposphere at Resolute the annual cycle is 

quite different from that at 1,000 mb, indicating that near surface air is not 

closely coupled with the free troposphere above. The Barrow surface ozone data 

are useful primarily in studying processes occurring in the lowest layer of the 

atmosphere, but the data are not highly representative of the free troposphere. 

Figure 12 shows updated monthly mean surface ozone values for each of the 

four GMCC baseline observatories through 1979. Except at Samoa , the 1979 data 

were obtained with the Dasibi ozone photometer. At Samoa, the more complete ECC 

data were used. As were data from previous years, daily mean, minimum, and maximum va lues are archived at the World Ozone Data Center in Toronto, Canada. 

29 
50 .----.----.----.----.----.----,----,----.----,----,----,,----.----,-__ -. 

40 

Barrow (71 0 N ) 

30 

20 

10 

40 j Mauna Loa ( 19.5° N) 

~ ~ 

D 30 0 

C 

~ 

S 

l' 

~ 20 ~ 

~ 

l' 

"-

~ 

t: 10 ~ 

"-

w 

c 

0 

N 

0 20 

Samoa (14° 5) 

10 

o 

20 Soulh Pole (900 S) 

10 

oL-__ J-__ _L __ ~ ____ L_ __ J-__ _L __ ~ ____ ~ __ _L __ ~ ____ L_ __ ~ __ ~ __ ~ 

1973 1974 1975 1976 1977 1978 1979 

Figure 12. --~lonthly mean surface ozone partial pressures measured at GNCC stations. 

30 
3.5 Stratospheric Water Vapor 

Establishing a program for routine stratospheric water vapor profil e measurements was much slower than anticipated. Problems developed in two crucial areas: 

the balloon system used to carry the frost point instrument in the stratosphere , 

and the production of the frost point instrument by the manufacturer. 

For many years a 7,000-gm neoprene balloon was used to carry the i nstrument 

aloft. This specially produced balloon was no longer satisfactory because a 

number of balloons burst before reaching the desired altitude. It thus became 

necessary to develop a new balloon system. Working with J. Mastenbrook of the 

Naval Research Laboratory, we designed and tested a 700-m3 plastic balloon with a 

controlled rip patch. This balloon, which ascends at a rate of about 275 m min- 1 

and descends at a rate of about 450 m min- 1 , has proved moderately re liable but is 

more cumbersome to launch than the neoprene balloon. Further work is be ing carried 

out to make the balloon system more reliable and simpler to launch . 

The other major problem experienced during the year was delay in transferring 

the technology for producing the frost point hygrometer to a commercial manufacturer. Several design changes were made by J. Mastenbrook to simp l ify the manufacture and improve performance. In earlier versions of the frost point instrument (see GMCC Summary Report 1978) the mirror temperature was kept at the frost 

point temperature by maintaining the size of the condensate on the mirror essentially constant. A recent improvement to the instrument maintains uniform density 

(thickness) of the condensate deposit and uses a more sensitive optical detection 

system to maintain the mirror temperature at the frost point temperature. 

3.6 Halocarbons and N20 

3.6.1 Operations 

Collection of air samples for CC1 3F (Freon-II), CC1 2F2 (Freon-12), and N2 0 

(nitrous oxide) analyses was continued during 1979 at the four GMCC stations and 

Niwot Ridge, Colo. Sampling and chromatographic analysis procedures remained 

virtually identical to those established in mid-1977 (Komhyr et a l ., 1980). 

During 1979 sampling frequency was increased at SPO. Beginning with the 1979-1980 

austral summer, the sampling rate at SPO one pair sample per week during summer 

and two pair samples per month during winter. At Niwot Ridge the evacuated flask 

sampling was replaced with pressurized air sampling, the method of sampl e collection used at all other GMCC stations. During an overlap period, 7 December 1979 

to 30 April 1980, air samples at Niwot Ridge were collected by both methods. 

Several problem areas were studied during the year. The scatter in the SPO 

data for all three constituents was relatively high compared with the data scatter 

at other stations. In most cases, questionable trace gas concentrations were 

probably too high because of contamination, but some unreasonably low concentrations were also noted. It is unlikely that such low values are representative of 

the Antarctic atmosphere. They probably result from adsorption of the trace gases 

onto walls of the sampl e cylinders because of prolonged sample storage. An attempt 

is being made to reduce the magnitude of this problem by selecting and using 

sample cylinders that have given reliable data in the past. The difficulties 

experienced point to the desirability of having an on-site gas chromo to graph at 

SPO for halocarbons and N2 0 measurements. 

31 
We determine halocarbon and N20 concentrations relative to moist air and use 

theoretically deduced conversion factors, including relative humidity data, to 

express results in terms of dry air. Experiments were conducted during 1979 to 

assess the validity of the theoretical conversion factors in use. 

Investigations were also conducted into the stability of trace gas concentrations stored in sample cylinders. It was possible to show that halocarbon and 

N2 0 concentrations did not change by more than 1% in air samples stored for 2 to 

3 weeks. This is a normal cylinder residence time for air samples collected at 

all GMCC stations except SPO. 

An important aspect of halocarbon and N20 monitoring is the procurement and 

maintenance of stable calibration gases. Uncertainties among various laboratories 

that prepare calibration gases range from ±5% for F-11 to ±10% for F-12 and N2 0. 

Instead of preparing calibration gases, we used a high pressure tank of air as a 

standard. The stability of the halocarbon and N2 0 concentrations in this primary 

standard tank (no. 3072) is being monitored by comparison with similar trace gas 

concentrations in several other tanks, as well as by interlaboratory comparisons. 

To date, we have no evidence of any change in F-11 and N2 0 in this primary standard. 

F-12, however, has been drifting at a rate of about 1% per year. F-11, F-12, and 

N2 0 concentrations within our primary standard tank no. 3072 have been calibrated 

by several laboratories . Results are summarized in table 13. 

In table 14 results of four multilaboratory F-11, F-12, and N2 0 intercomparisons are listed. GMCC concentrations for specific air samples are compared with 

Table 13. --Concentration in GMCC F-11, F-12, N2 0 primary reference standard tank 

no . 3072 as determined by various laboratories ' 

Calibrating Type of Concentration 

Date laboratory calibration N2O(ppbr) F-12(pptv) F-ll (pptv) 

Dec 1977 OGC D~'" 331. 4 353.4 149.1 

Oct 1978 OGC D 331.3 355.3 147.3 

Nov 1978 OGC D 331.5 357.2 149.4 

Apr 1979 NCAR D 317.7 253.7 140.3 

Apr 1979 AL/NOAA D 139.0 

Aug 19 79 OGC 1+ 328.0 243.2 148.9 

Oct 1978 NCAR I 325.3 255.6 139.0 

Oct 1978 AL/NOAA I 325.3 244 141 

Oct 1979 AL/NOAA I 360.6 251 151 

*Direct; +Indirect . 

32 
Table 14.--1nter laboratory trace gas concentration comparisons 

Comparison orga nizer GHCC va lue No. participating lab s Co nsens us va lue a 

(Ra s mu ssen ca libration) 

Rasmussen 1976 F-ll 145 15 140.2 16 

NBS 1976 F-ll 194 15 171 23 

Fra s er 1978 F-ll 143.6 7 146. 7 3 0 

156.0 8 156 0 5.5 

F-1 2 250.4 5 255.8 12.3 

258 5 254 7.3 

N20 335.4 5 325 .6 16 

332.0 5 323 14 

Ra s mus se n 1979 F-ll 71 19 62 8 

174 162 23 

F-1 2 123 19 110 13 

294 279 16 

N20 233 19 207 25 

337 321 13 

average concentrations for the samples obtained by several other laboratories. 

Rasmussen (OGC) calibration values were used for GMCC standards in these comparisons. Although most laboratories report a measurement precision of ±1%, the 

absolute calibrations vary by as much as ±10%, as shown by the standard deviations 

of the concensus values in table 14. Preliminary tests conducted in the Boulder 

laboratory indicate that the GMCC N2 0 data, reported in the OGC calibration scale, 

should be adjusted by the factor 0.898. 

3.6.2 The Data 

F-11, F-12, and N20 sample data for 1979 are plotted in figs. 13 to 15. All 

collected data are included in the plots except several «10) values that fell off 

scale. The gap in the South Pole record resulted from concentrating sampling 

there during the austral summer months. More sampling cylinders have since been 

procured, which will allow enhanced sampling frequency during summer months and 

sampling during winter. 

The gas chromatograph used for sample analyses was inoperative during much of 

August 1979, resulting in a 1 week or more data loss at all stations, followed by 

a several week period of questionable results. A small gap in the data record, 

followed by a number of scattered values, is evident in the August data plots. 

The data in figs . 13 to 15 have not been screened for background atmospheric 

conditions. One unexplained event indicated in fig. 14 is the significant increase 

33 
I- I I. I I I I I I I I ,_ 

200r- BRW' .- I- :,' .. ;: r •• --

180~. ;'::' : ' :0:,':": ': ' : .•• ·10,.:· = 

160r- - r- -

140~======================~ - - 200 - NWR -

180~.' "::: .. ,,' ..•. :.; ••. ' "::" :;;;._ 

160:::::' :' :. -

- -

14 0~=====================~ >" - - 0. 200- MLO - S - - 180>- .. :.~ .: :.: '''''' 

LLM >;- :::" ,::::::: "':' :'" :.' :: ~ Q l00~ . -

o 140~1-==============================~-

::E ,.0 . ...... , . " J ~:~~~="='=="=:='='='='=:="=:='='='='="='=':=='==;'========~~ - - 200 - SPO - - . -

180 - '.' '.-_ c- . 160,,·. . -

-'- '1 ' 1 1 I I I I I I I ,- 140 L-...L-L--'_L-...L-L--,-J_"--::--'-::-'---,-J'-::-' 

J F M A M J J A SON 0 

Figure 13 . --CCl 3F sampl e data obtained 

during 1979 at BRW, Niwot Ridge, MLO, 

SMO, and SPO . 

~ I I I I I I I I I = 

. BRW , 

= ~, :'. ' . I •••••• I': ,' " , .... . " : ... '., 1 " " 'I 

I'- = ~ -

400 

300 

200 

I-

~ NWR = 

t . , ; = .: :::: :, ,: :\ " t.: , ::'::. , ,.,," . .. .' :' . ~ 

400 

300 

= = - - 200 

= 

-

= 

MLO , .= .. .::; - .' .::: , • '., :" :', ,:.: .. -:' . ., :, ' . : ,, -' 

= = 

>" 

0. 400 

S 

N 

U. 300 N 

Q - - 0 200 

= = 

= 

SMO 

= 

400 

- - ~. : •••••• ,, ' • ••• , ••• • • • : • • 1 •••• ::.: •• ·.··." .. .: 

r-- . = r--

300 

200 

~ SPO = f:: = f':. : '. .. .-

r,:'I , ' . . . ;: 

f::, I 1 I 1 I I I 1 1 1 = 

400 

300 

200 

JFM A M JJASO ND 

Figure 14.--CCl2F2 sample data obtained 

during 1979 at BRW, Niwot Ridge, MLO, 

SMO, and SPO. 

in scatter of the Mauna Loa F- 12 data toward the end of the year. Another perplexi ng feature is the relatively high N20 growth rate (- 1% yr- 1 ) obs erved at SMO 

compared to that measured a t all other stations. Whether this growth rate is real 

or an artifact of sample co llection and analyses is not known. 

3.6.3 Data Ana l ysis 

The 1979 data support the conclusions concerning F-11, F-12, and N20 global 

abundances, latitudinal distributions, globa l growth rates, interhemispheric 

exchange rates, and atmospheri c lifetimes reported in the GMCC Summary Report 

1978. A decrease in the rate of increase of F-11 and F-12 in the global background 

atmosphere is indicated, howeve r, reflecting the decrease in production and release 

of these chemica l s into the atmosphere. The global growth rate of N20 is still 

not we ll established by the data that nevertheless s uggest a small interhemispheric 

gradient with larger va lues in the north. 

34 
Geophysical Monitoring 

for Climatic Change 

NO.9 

Summary Report 1980 

John J. DeLuisi, Editor 

Air Resources Laboratories 

Boulder, Co lorado 

December 1981 

U.S. DEPARTMENT OF COMMERCE 

Malcolm Baldrige, Secretary 

National Oceanic and Atmospheric Administration 

John V. Byrne, Administrator 

Environmental Research Laboratories 

George H. Ludwig , Director 
NOTICE 

Mention of a commercial company or product does not constitute 

an endorsement by NOAA Environmental Research Laboratories. 

Use for puhlicity or advertising purposes of information from 

this publication concerning proprietary products or the tests 

of such products is not authorized. 

ii 
CONTENTS 

ACRONYMS AND ABBREVIATIONS 

FOREWORD 

PREFACE . 

1. 

2. 

3. 

4. 

SUMMARY 

OBSERVATORY REPORTS 

2.1 Mauna Loa. 

2.2 Barrow .. 

2.3 Samoa. . . 

2.4 South Pole 

CONTINUING GMCC PROGRAMS. 

3.1 

3.2 

3.3 

3.4 

3.5 

3.6 

3.7 

3.8 

3.9 

3.10 

3.11 

Carbon Dioxide 

Total Ozone . . 

Ozone Vertical Distribution 

Surface Ozone . . . 

Stratospheric Water Vapor 

Halocarbons and N20 

Surface Aerosols 

Solar Radiation . . 

Station Climatology 

PreCipitation Chemistry 

Data Management 

SPECIAL PROJECTS. . . 

4.1 

4.2 

4 . 3 

4. 4 

4 .5 

4.6 

4 . 7 

4.8 

4.9 

4.10 

4.11 

4.12 

4.13 

Wind Climatology of American Samoa. 

Pyrheliometer Observations as an Indicator of the Climatological Persistence of Clouds . . . . . . . . . ... 

Sampling Strategy to Obtain Data Used in Models of Gl~bal 

Annual C02 Increase and Global Carbon Cycle . . . . . . 

Decomposition of Annual Variations of C02 Concentration 

at GMCC Flask Sampling Stations Into Three Patterns . . 

Comparison of Airborne C02 Flask Samples and Measurements 

From ~ILO During the RAMEC Project (June 1980) ..... . 

C02 Measurements at Barrow, Alaska .... . ...... . 

Some Optical Properties of Arctic Haze at Barrow, Alaska. 

Mauna Loa Atmospheric Transmission: An Update . . 

A Relationship Between Pacific Ocean Temperatures and 

Atmospheric C02 Concentrations at Barrow and Mauna Loa. 

A Possible Drought-Induced Signal in the Global Atmospheric C02 Record . . . . . . . . . . . . . . . . . . 

Studies of Variability in C02 Concentration at Barrow 

Related to Synoptic Meteorology . . . . . . 

A Report on the Short Umkehr Method . . . . 

Remote-Sensing Observations of the Mt. St. Helens Cloud 

iii 

Page 

v 

vi 

viii 

1 

4 

4 

10 

13 

15 

19 

19 

23 

29 

31 

33 

34 

36 

44 

46 

56 

58 

62 

62 

64 

68 

71 

74 

80 

83 

86 

88 

89 

91 

92 

96 
5. 

6. 

7. 

8. 

9. 

4.14 Interpretation of Precipitation Chemistry Event Sampling 

at Elevations From Sea Level to 3400 Meters on the Island of Hawaii ... 

4.15 Stratospheric Lidar Investigations of the Mt. St. Helens 

Volcanic Cloud over Boulder, Colorado 

COOPERATIVE PRO GRAtIS 

5.1 

5.2 

5.3 

5.4 

5.5 

5.6 

5.7 

5.8 

5.9 

5.10 

5 . 11 

5.12 

5.13 

Size-Elemental Profiles of Fine Particulate Matter at 

Mauna Loa and Hilo, Hawaii (Univ. of Calif., Davis) ..... 

Ultraviolet Erythema Global ~Ieasuring Network (Temple Univ.). 

Radiation Balance Measurements at Barrow (Univ . of Alaska) .. 

Characteristics of Aerosol Concentrations at the Threshold of 

Detectability (SUNYA) . . . . . . . . . . . . . . . . . . 

Aerosol Characteristics at Mauna Loa Observatory, Hawaii, 

After East Asian Dust Storm Episodes (Fla. State Univ.) 

Arctic Haze Studies at Barrow (URI) . .. . .... . 

The SEAREX Program--An Overview (URI) . . .... . . 

Site Evaluation and Facility Construction for SEAREX Experiments in American Samoa (URI -CIT) . . . . . . . . . 

Carbon Particles in the Arctic Aerosol (LBL-NOAA) . . . . . . 

Solar Spectral Irradiance and Transmissivity of the Atmosphere 

at Mauna Loa During 1980 (Univ. of Alaska) ..... 

Increases in Atmospheric Concentrations of Halocarbons 

and N20 (OGC) . . . . . . . . . . . . . . . . . . . .. 

Precipitation Chemistry at Samoa and Mauna Loa (DOE/EML). 

Atmospheric Particulate Chemistry at the South Pole and 

Mauna Loa (Univ. of Md.). 

INTERNATIONAL ACTIVITIES 

PUBLICATIONS AND PRESENTATIONS . 

REFERENCES 

GMCC STAFF 

99 

99 

103 

103 

104 

104 

105 

107 

113 

116 

118 

122 

127 

134 

139 

141 

148 

150 

153 

162 
ARL 

BRW 

CAF 

CIT 

CNC 

DOE 

ECC 

EML 

EPA 

G.E. 

HMfEC 

HVO 

lAEA 

IAl'tAP 

ICDAS 

ISWS 

LBL 

MLO 

~IPI 

NADP 

NARL 

NBS 

NCAR 

NCC 

NIP 

NOAA 

NRL 

NSF 

NWS 

OGC 

PIXE 

SEAREX 

SIO 

S~1O 

SPO 

SRL 

SUNYA 

URI 

USGS 

WHO 

WDC-A 

ACRONYMS AND ABBREVIATIONS 

Air Resources Laboratories, Washington, D.C. (NOAA) 

Barrow Observatory, Barrow, Alaska (GMCC) 

Clean Air Facility, South Pole Observatory, Antarctica (GMCC) 

California Institute of Technology, Pasadena, Calif. 

Condensation nucleus counter 

U.S. Department of Energy, Washington, D.C. 

Electrochemical concentration cell 

Environmental Measurements Laboratory, U.s. Department of Energy, 

New York, N.Y. 

Environmental Protection Agency 

General Electric 

Hawaii Mesoscale Energy and Climate project 

Hawaii Volcano Observatory 

International Atomic Energy Agency, Vienna, Austria 

Internationa l Association of Meteorology and Atmospheric Physics 

Instrumentation control and data acquisition system 

Illinois State Water Survey 

Lawrence Berkeley Laboratory, Berkeley, Calif. 

Mauna Loa Observatory, Mauna Loa, Hawaii (mICC) 

Max Planck Institute, ~Iainz, Germany 

National Atmospheric Deposition Program 

Naval Arctic Research Laboratory, Barrow, Alaska 

National Bureau of Standards, Gaithersburg, Md. 

National Center for Atmospheric Research, Boulder, Colo. 

National Climatic Center, Asheville, N.C. 

Normal incidence pyrheliometer 

National Oceanic and Atmospheric Administration, U.S . Dept. of 

Commerce 

Naval Research Laboratory 

National Science Foundation, Washington, D.C. 

National Weather Service, Washington, D.C. (NOAA) 

Oregon Graduate Center, Beaverton, Ore. 

Particle (or proton) induced X-ray emission 

Sea-Air Exchange program 

Scripps Institution of Oceanography, La Jolla, Calif. 

Samoa Observatory, American Samoa (GMCC) 

South Pole Observatory, Antarctica (GMCC) 

Smithsonian Institution Radiation Biology Laboratory 

State University of New York at Albany 

University of Rhode I sland, Kingston, R.I. 

United States Geological Survey 

World Meteorological Organization, Geneva, Switzerland 

World Data Center-A, Asheville, N.C. 

v 
FOREWORD 

However we may define climate, and I know of no satisfactory formal way, 

we do know that it changes. We know this from the 200 or 300 years of local 

instrumental records, from the 100 years of global instrumental coverage , and, 

more certainly and significantly, from what Wilmot Hess, in the foreword to 

the first of these Summary Reports, called "ingenious studies of glaciers, 

pollen, tree rings, sea sediments, and vintners' records." The changes 

appear on all the time and space scales we have been able to study, and, where 

it has been possible to quantify the changes statistically, the statistics are 

neither stationary nor homogeneous and, furthermore, do not lend themselves 

easily even to quantitative extrapolation in time. 

What then can be the purpose of an organization devot ed to "Geophysical 

~lonitoring for Climatic Change"? Clearly not to establish the fact that 

climate changes, nor, in view of the very large quantity of standardized 

meteorological observations and of the growing potential of satellite systems, 

to document climate change on the global or any regional scale. The traditional role of monitoring is to provide a timely indication of situations 

which are about to become manifest, and the traditional monitor is a very 

sensitive detector of some parameter which is itself a very sensitive indicator that tbe situation is in being. (A simple analogy to this is a smoke 

detector alarm.) I do not believe that such an indicator of climate change 

has yet been unambiguously identified, but there are some very likely candidates, and GMCC is observing them, systematically and with the greatest 

precision possible, in locations where interference by strictly local activity 

is absent or can be contained. Such locations are remote, preferably barren, 

and usually uncomfortable, and operation there is expensive. 

Economic conditions change as well as statistics of weather, and, as I 

write, I am only too well aware of a potentially significant reduction in the 

resources available for study of the atmosphere. Therefore, the general 

atmo spheric research community is being faced with the problem of curtailing 

certain programs. Serious thought must be given to retaining the continuity 

of measurement programs that offer a reasonable chance for unraveling the 

factors and comb inations thereof that cause climate change. Consider, for 

example, the record of C02 concentration in the atmosphere. If much of the 

thinking on this problem is not in error, the effects of CO2 concentration 

increases on global climate should begin to sh6w in the global statistics 

(perhaps of temperatures in the higher stratosphere) within the next 10 years. 

If effects do not show, we will have a scientific problem, and, in considering 

the problem, detail in the record of C02 concentration will be important . If 

the effects do show, we will have an economic problem with enormous implications, and detail in the record of C02 concentration will be important in 

studying its impact. At the present time GMCC carries a major responsibility 

for the continuity and precision of the C02 record. The same reasoning can be 

applied to the other trace gases and aerosols measured by GMCC. It is a 

responsibility to the world community. 

For a 10-yr period some time ago, I was the Superintendent of Kew Observatory. This institution, for a total of 120 years, bas maintained a commendably continuous record of certain weather elements measured in precisely 

defined conditions. This record has been used for assessments of past climate 

conditions . (For example, it clearly showed the cold spell of 1880-1890.) 

When the record was begun, I believe it was unique. After very careful consideration of the Kew record in relation to other records from nearby sources, 

vi 
and for reasons of economy, the Observatory was recently closed and the record 

ended. It was ascertained that continuity would not be lost because of the 

overlapping measurements made by the other nearby observation facilities. The 

physical surroundings of Kew had unavoidably changed over the years, and the 

effects could be seen in the record. Therefore, although I have sentimental 

r egrets, I cannot think of any possible adverse effect of the closure on 

atmospheric science. 

I view GMCC as representing a new generation of observatories which are 

designed partially on the basis of experiences of the older observatories, but 

which are now internationally connected and judiciously located for detecting 

changes that are more likely to be global in nature . Modern equipment has 

greatly i mp roved capabilities for measuring an extended variety of atmospheric 

variables, including aerosols and chemistry, and it is expected that the 

r emotely located sites will ensure minimum influence from changes in surroundings for many years. A valuable and mor e complete record for climate research 

i. s now being accumulated by these newer observatories, and I believe it will 

be a considerable number of years before these observatories will have found 

their mission fulfilled. 

G. D. Robinson 

Past President and Honorary Kember 

Royal Meteorological Society 

vii 
PREFACE 

This document presents a summary of the research operations and accomplishments by the Geophysical Monitoring for Climatic Change (GMCC) program 

and by outside investigators working cooperatively with GMCC in 1980. It 

includes descriptions of management and operations at G~ICC's four baseline 

sites, scientific data from the meas urement projects, conclusions from 

analys es of data, and recent basic research achievements. 

The GMCC program, established in 1971, is one of five research programs 

within the Air Resources Laboratories under the directors hip of Lester Machta. 

Its four observatories are located at Barrow, Alaska (in service since 1973); 

Mauna Loa, Hawaii (in service since 1956); American Samoa (in service since 

1973); and South Pole (in service since 1957). Background measurements of 

aerosols, gases, and solar radiation that are important to the climate of the 

Earth are made at the observatories. The primary groups within GMCC are 

Monitoring Trace Gases, Aerosols and Radiation ~Ionitoring, Acquisition and 

Data Management, and Analysis and Interpretation. SpeCific names of individuals in GMCC are not given in the main text of the report; however, the 

membership of each GMCC group is given in sec. 9. Publications and presentations by GMCC staff are given in sec. 7. 

viii 
GEOPHYSICAL ~IONITORING FOR CLII1ATIC CHANGE 

NO. 9 

Summary Report 1980 

1. SUmlARY 

At Mauna Loa, an LSI-II computer system was ordered for the Hilo office 

to be used for local research projects . An investigation of C02 vertical 

gradients started. Complete refurbishing of the lidar system laser greatly 

improved operations in 1980. The Meteorological Museum was in operation for 

its first full year. At Barrow, the Naval Arctic Research Laboratory went to 

caretaker status, thus terminating its science support activities. GMCC 

personnel moved to housing provided by NWS i n the town of Barrow . 

At Samoa, five temporary facility additions were made in prepa ra t ion for 

hosting the SEAREX experiment . A comprehensive tracer study of the airflow 

around Matatula Point was pe rformed by SEAREX and GMCC personnel to determine 

possible contamination effec ts from local vegetation and cerrain. At South 

Pole, no additions to facilities were made and all programs operated normally. 

The main ongoing GMCC measurement programs at t he Observatories cont inued; 

these include carbon dioxide, surface and tota l co lumn ozone, fluorocarbons-II 

and -12, nitrous oxide, aerosol sca ttering coefficient, Aitkin nuclei, solar 

radiation components, chemistry of precipitation, and associated meteorology. 

In addition, balloon measurements of stratospheric water vapor and ozone 

profiles were made at Boulder along with frequent Umkehr ozone profiles . 

Lidar measurements continued at Mauna Loa. Total ozone was r egularly measured at eight additional site s by Dobson spectrophotometers. The C02 flask 

sampling program was expanded by three, to 18 locations (including the 

Observatories). Many of these data are being archived at the World Data 

Center-A, Asheville, N.C., and at the World Ozone Data Center, Downsview, 

Ontario. 

Upgrading of foreign Dobson spectrophotometers, under the auspices of 

the WHO Global Ozone Research and Monitoring Project, continued . To date, 40 

instruments have been directly ca librated and 40 others indirectly calibrated 

relative to the World Primary Standard Do bson no . 83, maintained at GMCC in 

Boulder. Work continued on automation of a Dobson for routine Umkehr meas ure -

ments using the short technique. This wi ll allow an inc reased number of ozone 

profiles at reduced sta ff costs. 

Climatology analyses for the four mlcc Observatories, using the sta tions' 

meteorology data, were perfo rmed and reported. Precipitation chemistry protocol at the ba seline and r egional stations was changed significantly in 1980; 

all GMCC sites adopted common protocol and proced ures of the National Atmospheric Deposition Program. 

New hardware was acquired to upgrade the Boulder data reduction f ac ility . 

This included a NOVA 4/X minicomputer and a Winchest er-type disk. Also, 

stand-alone microprocessor-based data loggers were being developed. 
GMCC personnel conducted numerous research projects and data analyses 

from ongoing programs. Among the topics included were analyses of secular 

trends of North American total ozone, fluorocarbo n-ll and -12, N20 , Aitkin 

nuclei, and aerosol light scatter. In recent years, total ozone showed a 

slight decrease, whereas fluorocarbons continued their ma rked increase. 

Aitkin nucleus values at the South Pole (for example) have shown little yearto-year change. 

A climatology of airflow arriving at Samoa indicates that during late 

summer Northern Hemisphere air occasionally, but infrequently, reaches the 

Observatory. C02 anomalies have been detected during such times. 

Mauna Loa normal incidence pyrheliometer data were used to develop a 

technique for obtaining thin-cloud climatology. A persistent trend in thinc loud transmittance would indicate regional changes in cloud optical thickness. 

GMCC C02 data were used for several studies. Intermittent flask samplings at selected sites around the globe are expected to contain fluctuations due to small-s cale events not of interest for global-scale concerns. 

The effect of station distribution and frequency of sampl ing was studied to 

develop a strategy for providing a truly global annual C02 increase. In 

another study, an eigenvalue analysis of GMCC flask samples yielded largescale characteristic patterns. 

The GMCC C02 measurement record from Barrow, 1973-79, was analyzed in 

some detail. An annual cycle of about 15 ppm was identified. These other 

investigations of atmospheric C02 characteristics are swrunarized in this 

report: relationships between Pacific Ocean temperatures and concentrations of 

atmospheric C02 concentrations at Barrow and Mauna Loa; a possible droughtinduced signal in the globa l atmospheric C02 record; the variability of C02 

concentration at Barrow related to synoptic meteorology; and a comparison of 

mid tropospheric airborne samples with measurements at MLO as part of the HAMEC 

project. 

Further work was accomplished on the short Umkehr method . A computer 

program to invert short Umkehr measurements was completed and tested on 46 

s hort Umkehr observations, and the results were compared with concurrent 

ozone sonde measurements. Generally good agreement was obtained. 

Measurements of the atmo spheric radiative effec ts of the Mt. St. Helens 

volcanic cloud that appeared over Boulder on May 19 and June 3 were made and 

subsequently analyzed for the optical properties of the cloud. About 5% of 

the solar attenuation occurred as absorption. Stratospheric lidar measurements were a l so made of the cloud at various times between May and August. 

Distinct aerosol layers were detected at altitudes between 10 and 20 km. 

Solar radiation measurements made at Barrow were analyzed for optical 

properties of the Arctic ha ze during specific episodes when haze was evident. 

The technique used to analyze radiation measurements for aerosol properties 

indicates that a preponderance of small particles exist in the haze. The 

direct solar beam was depleted by as much as 29%. 

In 1980, GMCC supported a substantial number of cooperative research 

projects . (At Mauna Loa alone, there were about 20 cooperative programs.) 

2 
Thirteen summary reports from the projects were contributed to this volume . 

Several aerosol chemistry investigations were conducted, leading to va luable 

quantitative interpretation of the characteristics of aerosols sampled at the 

Observatories. Measurements at Barrow further confirmed that Arctic haze is 

probably anthropogenic. Moreover, the radiative properties of the Barrow 

winter aerosol appear to be strongly absorbing in the solar visible band. 

The solar spectral irradiance and transmission by the atmosphere at Mauna Loa 

were critically investigated. Sampling of atmospheric gases, crucial to the 

photochemistry of ozone production, continued, further extending the record 

built from the previous sampling projects. Methane measurements at Barrow 

and Samoa were us ed to document a global secular increase . A major atmospheric chemistry field program, SEAREX, with multi-institution participation, 

began at Samoa. 

3 
2. OBSERVATORY REPORTS 

2.1 tlauna Loa 

2 . 1 .1 Equipment and Facilities 

No major changes to the basic facilities at Mauna Loa (MLO) were effected 

during t he year. Perhaps the most important action was identifying a new 

computer system for quality control of MLO data and for computations related 

to specia l research projects of MLO staff members. The spec i f i ed system is 

based on t he LSI- I I microprocessor, with peripherals inc l uding a disk system, 

video terminal, and line printer. In addition, an automatic plotter was 

obtained as government excess equipment. 

Aside from t he computer system order, the fo llowi ng problems with, or 

modifications to, t he MLO facilities occurred during 1980. 

(1) A severe storm accompanied by winds gusting to 85 mi h- 1 buffeted 

Hawaii during t he period January 8-12 and caused some damage to the buildings 

at the observatory. The most serious damage was sustained by the storage 

bui l ding , which l ost part of its roof. Minor damage at other locations was 

caused by flooding from the 5-in rainfall accompanying the strong wind. 

Cleanup and repairs of the damage were completed by the end of January. 

(2) Operation of the instrumentation control and data acquisition 

system (ICDAS) was interrupted 25 times during the year, most frequently because of instantaneous dropouts of line power, but, closely second, because of 

static discharges in the vicinity of the computer. The reason for one 5-day 

outage was inadvertent shorting of a destructive voltage through a special 

circuit that had been installed for monitoring the magnetic tape unit. Problems in reading t he operating system tape were experienced on occasion. In 

general, however, ICDAS operations were as satisfactory as can be expected for 

a complicated system in a remote location. 

(3) A damaged sun photometer was replaced by a new one in March. 

(4) A major i mprovement of the lidar system was completed, with an 

increase of laser power by about an order of magnitude. The previously used 

3/8-in r uby rod was replaced by a 5/8-in rod, and previously damaged windows 

and mirrors were replaced by new ones. Fortunately, t his was all accomplished 

before t he eruption of the Mt. St. Helens volcano. 

(5) A detailed map of the MLO site, the first such map ever developed 

for MLO, was completed in June. Not only are the building locations defined 

precisely for t he first time, but a very useful diagram of t he electric power 

dist ribution system of the observatory was developed. As a res ult, two comp l etely use l ess loops in the electric cables were discovered and eliminated. 

(6) A URAS-l carbon dioxide analyzer was received from Boulder in July 

and was set up with a multilevel air intake system for investigating vertical 

gradients of C02 concentration under different meteorological conditions. 

(7) In a continuing effort to protect the observatory from possible lava 

flows resulting from eruptions of the volcano, a very detailed and precise 

topographic map of the upper regions of Mauna Loa was completed in December by 

4 
the U.S. Geological Survey (USGS), Flagstaff, Arizona, from special aerial 

photos. Arrangements for both the aerial survey and construction of the map 

were made by J. P. Lockwood of the Hawai i Volcano Observatory (HVO) , who is 

also developing plans for the construction of lava barriers above the observatory for deflecting any lava flows that may originate on the higher slopes of 

the volcano. 

(8) One of the automobiles (a Plymouth Fury) assigned to MLO was replaced by a newer model (a Ford Fairmont station wagon) in 1980. This vehicle 

is much more suitable for hauling the many boxes of flasks and instruments 

used at the observatory. 

2.1.2 Programs at ~~O during 1980. 

The principal programs carried out at MLO during 1980 are listed in 

table 1 . Brief comments on the programs follow. 

Carbon Dioxide 

The URAS-2 infrared analyzer continued to operate without major problems 

during the year, the output being recorded on both the ICDAS magnetic tape and 

a strip chart recorder. In addition, pairs of 500-mQ glass flasks were 

exposed weekly at MLO and Cape Kumukahi and sent to Boulder for analysis. A 

number of special high density, flask sampling periods occurred throughout the 

year in connection with programs such as the ~lliC (Hawaii Mesoscale Energy 

and Climate) project and tests of new methods of flask sample analysis in 

Boulder. 

A special project for investigating vertical gradients of CO 2 concentration was started near the end of the year. Samples are taken at five different levels up to a maximum height of 88 ft above the surface . No definite 

results were obtained before the end of the year. 

Outgassing from the volcanic caldera at the summit of Mauna Loa continued 

to be recorded in the CO 2 continuous-monitoring measurements, mainly during a 

downslope windflow regime. Table 2 shows the monthly frequency of occurrence 

of the outgassing for 1980. The total freque ncy of outgassing from the 

caldera for 1980 corresponded well with frequencies in 1978 and 1979, as shown 

by table 3, but was lower than the years immediately following the July 1975 

summit eruption of Mauna Loa. Seismi c and other measurements of HVO indicate 

that the volcano will remain in a generally stable condition, with a slow 

expansion of the summit area. 

Atmospheric Ozone 

Total ozone in the atmospheric column was measured on each of approximately 250 days during 1980 by Dobson spectrophotometer no . 63. In addition, 

the standard reference spectrophotometer no. 83 was shipped from Boulder to 

make a special series of measurements over approximately 2 months. 

Surface ozone concentration was monitored continuously throughout the 

year by Dasibi and ECC (electrochemical concentration cell) instruments. 

5 
Table 1.--Summary of monitoring programs at Mauna Loa in 1980 

~Ionitoring Program Instrument Sampling frequency 

Gases 

Carbon diox ide 

Surface ozone 

Total ozone 

Fluorocarbons 

Aeroso ls 

Stratospheric aerosols 

Co nden sation nuclei 

Optical properties 

Skylight po la rization 

Solar radiation 

Global irradiance 

Ultraviolet irradiance 

Direct beam irradiance 

~Ieteorology 

Maximum temperature 

Minimum temperature 

Ambient temperature 

Dewpoint temperature 

Relative humid ity 

Total pre cipitable water 

Pressure 

Precipitation 

l,Jindspeed 

Wind di recli on 

Precipitation chemistry 

Acidity of rainwater 

Conductivity o f water 

Chemical components 

Cooperative programs 

Carbon dioxide (SIO) 

Carbon monoxide (MPI) 

Surface S02 (EPA) 

To tal surface particulates 

(ooE) 

URAS-2 infrared gas analyzer 

Evacuated glass flasks 

Electrochem ica l concentration cell 

Dasibi ozone meter 

Dobson spectrophotometer (H63) 

Dobson spectrophotometer (nS3) 

Pressurized flasks 

Lida r 

Pollak CN counter 

G. F.. CN counter 

Four-wavelength nephelometer 

Polarizing radiometer 

Four Eppley pyranomete rs 

Eppley ultraviolet pyranometer 

Eppl ey pyrheliome t er 

Eppley pyrhel iometer with fi lters 

Eppley 13-channel pyrheliometer 

Maximum thermometer 

Minimum thermometer 

Thermistor 

Hygrothe rmograph 

Dewpoint hygrometer 

Hygrothermograph 

Fos keLl infrared hygrometer 

Electroni c pressure transduc er 

Hicrobarograph 

Rain gage, 8-in 

Rain gage, 8-in 

Rain gage, tipping bucket 

Anemometer 

Wind vane 

pH meter 

Conductivity bridge 

Ion chromatograph 

Infrared analyzer (Applied Physics) 

Evacuated flasks 

Special system 

Chemical bubbler system 

High-volume filter 

Total surface particulates High-volume filter 

(EPA ) 

Atmospheric electricity 

(Univ. o f Minnesota) 

Ultravio l et radiation 

(Temple Univ.) 

Precipitation collection 

(DOE) 

Precipitation collection 

(EPA ) 

Precipitation collection 

(Univ. of Paris) 

Precipitation collection 

(IAEA) 

Wet - dry deposition 

(Univ. o f III inois) 

Atmospheric aerosols 

{Florida State Un iv. 

Atmosphe ri c aerosols 

(Univ. of Maryland) 

Atmospheri c aerosols 

(Univ. of California) 

Atmospheric aerosols 

(Univ. of Arizona) 

Field mill, air conductivity 

meter, surface antenna 

Ultravi ole t radiometer 

Wet-dry collector (Health and 

Safety Lab.) 

Misco model 93 

Likens funnel collector 

Likens funnel collector 

Exposed co llec tion pails 

Special filters 

Nu c l epore filters 

Nuclepore rilters and impacto rs 

Quartz filters 

6 

Continuous 

Weekly 

Conti nuous 

Continuous 

Discrete 

Discrete 

Weekly 

Weekly 

Discrete 

Con tinuous 

Con tinuous 

Discrete 

Continuous 

Cont i nuous 

Continuous 

Discrete 

Continuous 

Daily 

Dai ly 

Continuous 

Continuous 

Conti nuous 

Continuous 

Continuous 

Continuous 

Continuous 

Oai ly 

Twice weekly 

Continuous 

Continuous 

Continuous 

Discrete 

Discrete 

Discrete 

Conti nuous 8 mo- 1 

Conti nuous 

Every 12 days 

Continuous 

Every 12 days 

Continuous 

Continuous 

Continuous 

Continuous 

Twice weekly 

Twice weekly 

Continuous 

Con tinuous 

Conti nuous 

Night only 

Continuous 

Remarks 

Hountain and seacoast 

3 meas., weekdays; 0, weekends 

Special obs. during sumn:er 

694.3 nm, 1 J 

4 meas., weekdays; 0, weekends 

Wavelengths 450 , 550, 700, 850 nm 

8 \o·ave lengths 

Cutoff filters at 280, 390 , 530, 

695 run 

Wavelength range 295 to 385 run 

Wavelength range 280 to 3,000 rum 

Cuto f f filters at 280, 530, 630, 

695 nm 

13 s pectral regions 

At HLO and Kulani Mauka 

At MLO and Kulani Mauka 

At MLO 

At Kulani ~Iauka 

Rainwater collections at 6 sites 

Mountain and seacoast 

Chemica l reaction wit h IIgO 

Dependent on wind direction 

Radiation responsible for sunburning of skin 

Natl. Atmos. Deposition Program 

Day-night discrimination 

Day-night discrimination 
Table 2.--Monthly occurrences of outgassing from the 

volcanic caldera on Mauna Loa 

Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec 

No. of days 3 0 9 8 7 16 19 21 11 10 9 8 

Percent of 10 0 29 27 23 53 61 68 37 32 30 26 

days 

Atmospheric Aerosols 

The aerosol-monitoring program, including the volume scattering coefficient and concentration of condensation nuclei (eN) in the air, continued 

without major interruptions during the year. 

Lidar Observations 

As mentioned above, complete refurbishing of the laser, a process which 

involved purchasing new optical components and repolishing some existing 

comp onents, resulted in lidar operations in 1980 that were much i mproved over 

previous years. Although the optics were all in order by the end of March, 

electronic problems continued to prevent regular observations for another 

month. Beginning in May, however, lidar observa tions were made routinely 

throughout summer and fall. Twice-weekly observations were made for several 

weeks following the Mt. St. Helens eruption, but this schedule caused an 

undue burden on the available staff, so a weekly schedule was set up. The 

Mt. St . Helens volcanic cloud was first detected over Mauna Loa in early 

J uly, some 6 weeks after the May 18 eruption. Intense public interest in the 

cloud was evidenced by numerous telephone calls received in Hilo following a 

press release on the event issued by NOAA in Boulder. The lidar continued to 

operate well, and evidence of the volcanic cloud persisted, until failure of 

the laser on December 24 terminated lidar measurements for the year. 

Solar Radiation 

Solar radiation observations continued without serious problems during 

1980. Perhaps the most significant difficulty was that improper alignment of 

Table 3.--Annual frequency of occurrence of outgassing from the caldera 

on Mauna Loa during the period immediately before and since 

Percent of 

occurrences 

the last summit eruption, July 1975 

1975 1976 1977 

Jan-Jul Aug-Dec 

28 49 42 43 

7 

1978 1979 1980 

32 32 33 
the shading disk for diffuse solar radiation measurements degraded the measurements on occasion during the first 8 months of the year. A careful realignment on September 11 eliminated the difficulty, however, and compleLely 

reliable diffuse data were obtained during the remainder of the year. 

Lightning discharge near the observatory burned out the preamplifier for 

diffuse radiation measureme nts on May 12 and again on May 20. Installation 

of l ightning protectors on ~lay 25 apparently corrected the problem . The 

qua rtz window pyranometer and two normal incidence pyrheliometers were compared with the Boulder traveling standards, from January 29 to February 1. 

Meteoro l ogical Parameters 

Satisfactory monitori ng of the basic meteorologi cal parameters continued 

during 1980, with only the norma l number of equipment problems. An intermittent problem was encountered in automatic recording of ambient temp erature, an erroneous thermometer calibration constant in the data acquisition 

system was discovered and correc ted in August, and a spare temperature card 

and sensor were installed i n late September. The aerovane directional servomotor malfun ctioned and caused erroneous wi nd direction data from July 17 to 

23. The triple register for wind and precipitation was inoperable April 

through Hay, but was put back online on June 6 and operated satisfactorily 

for the remainder of the year. 

Precipitation Chemistry 

Measurements of the acidity, conductivity, and ion content of rainwater 

samples from six sites i n Hawaii, as well as of samples from the other G~ CC 

observatories, were continued on a regulC:t[ iJa::;is, and rainwater samples were 

sent regularly to the International Atomic Energy Agency (IAEA) and the 

University of Paris . A special effort in collecting and analyzing numerous 

rainwater samples was made during the HAHEC project, the efhcial period of 

which was June 11 t o 24. Aid was also given to the Illinois State Water 

Survey (ISWS) in its sequential rain-sampling program. 

Fluorocarbons (Ha locarbons) 

Dual flask samples were taken on a weekly basis and mailed to Boulder for 

analysis . 

li ght Polarization and Intensity 

Measurements of the polarization and intensity of skyligh t , mainly 

during periods of morning twilight, were coordinated with lidar measurements 

of stratospheric aerosols . 

Cooperative Programs 

A significant component of NLO is the cooperative projects that are 

carried out by obse rvato ry personnel f or various universities and government 

agencies . Nost of the cooperative programs listed in table 1 were continued 

through 1980 without major difficulties. The following items are worthy of 

special note. 

(I) A. Dittenhoefer, an associate in the National Research Council 

Associateship Program, spent the entire year at MLO conducting a study of 

8 
the s ulfate content of atmospheric aerosols. The results are scheduled for 

publication during 1981. 

(2) Special sol ar radiation measurements, which covered the period of 

Ja nuary 22 to tbe end of the year, were conducted by G. Shaw of the University of Alaska . The measurements we re made by a 10-filter solar tracking 

radiome t er operated by G. Ferre l, a University of Alaska technician who wa s 

sta tioned at HLO throughout the period. 

(3) New i nstrumentation for carbon monoxide measurements was installed 

during Har ch by scientists from the Max Planck Institut (HPI), Hainz, Germany. 

This equipment is mu ch more sensi tive than the previous instrument, and, 

excep t for a short period during early Hay, it operated sa tisfactorily the 

remainder of the yea r. 

(4) Special so lar ra di ation mea surements we re made by R. Angione, 

R. Roosen, and F. Beale of San Diego State Un iversit y for seve ral days during 

late Harcb. A malfunction of the microprocessor caused a premature termination of the meas urements , however, and the equipmen t was r e turned to San Diego 

in time for investiga ting tbe radiative effects of the Nt. St. Helens volcanic 

cloud as it passed over San Diego. 

(5) At tbe request of R. Fraser of the Goddard Space Flight Cente r, 

specia l measurements of solar r adiation in eight different spectral band s were 

made during late June and ea rly J uly to obtain an approximate ca libration of 

Fraser's radiometer using Langley plots of the rad iation data. 

(6) During Marrh, V. Neitzert of HPI took fifty 3-h samples for atmospheric formaldehyde analysis . Liquid nitrogen was us ed to freeze from the 

sample s many of the atmospheric gases, forma ldehyde among them, and the 

resulting material was fixed in a liquid r eagent and taken back to Germany for 

ana l ysis . 

(7) Al so during March, M. Darzi of Florida State University used Cascade 

i mp actors at severa l lo ca tions on the island for special aerosol collections 

that were later analyzed in Darzi's laboratory by the particle induced X-ray 

emissi on technique (PlXE) . 

(8) A major revision of the aerosol collection experiment of the University of Maryland was made during the latter part of April. The previous three 

pumps were replaced by much more powerful ones, thereby increa sing the airflow 

rate by a factor of 4 to 5. Operation of the new pumps is controlled by a 

soph isticated system of circuitry triggered by four environmental parame ters 

at the observatory; windspeed, wind dire ction, atmospheric scatte ring coefficient, and concentration of condensation nuclei. The system operated well 

during the remainder of the year. 

(9) A new procedure for handling wet-dry atmospheric deposition samples 

was instituted on June 19, at t he time of the HAMEC proj ect . Following that 

date, weekly samples of wet fal l out and bimonthly sample s of dry fal l out have 

been submitted to ISWS for chemi ca l analysis . The samples are taken as a part 

of the National Atmospheric Deposition Program (NADP). 

(10) Word was received during July that management of the atmospheric 

electricity program wa s being transferred from W. Boeck, Niagara University, 

9 
to D. Olson, University of ~Iinnesota. One month later, a new and improved 

field mill and a new antenna for measuring air-Earth current were installed at 

the observatory. It had been anticipated that data from all the atmospheric 

electricity instruments would be recorded on magnetic tape by an electronic 

data acquisition system to be delivered with the new instruments. Unfortunately, the theft of the data logger from an automobile parked overnight in 

Hilo forced the use of two antiquated strip chart recorders on an interim 

basis until a new electronic system can be obtained. The strip chart recorders were still in use at the end of 1980. 

(11) Two scientists, A. Ashbridge and J. Bellfleur of the Environmental 

Service of Canada, brought the Canadian Dobson spectrophotometer and a Brewer 

ozone meter to MLO in late July for comparison of their instruments with the 

standard Dobson no. 83. They returned to Canada on August 8, having experienced exceptionally good sky conditions at MLO during the comparison period. 

(12) A. Hogan, State University of New York at Albany (SUNYA) , made some 

special aerosol collections at MLO during the period June 10 to 18 to measure 

the size-frequency distribution of the particles. 

(13) The laborious task of reading values from the meteorological data 

charts and transcribing them by hand into tabular format for use by the 

Scripps Institution of Oceanography (SIO) carbon dioxide program was terminated on July 1. After that date, the meteorological data were transcribed in 

Boulder from the MLO magnetic data tape. Hand reduction of the C02 data from 

recorder strip charts continues as it has since the start of the measurements 

in 1958. 

2.1.3 Mauna Loa Meteorological Museum 

1980 was the first full year of the existence of the Meteorological 

Museum at MLO. The collections were increased during the year by the following items: 

(1) A 4- by 8-ft airbrush painting of Mauna Loa and its environs. 

(2) Eight meteorological instruments of various types. 

(3) Several dozen books, charts, pamphlets, and other published material on 

meteorological and related topics. 

(4) Original hand-written letters and manuscripts, mainly by the late C. G. 

Abbot. 

(5) Magnetic tape cassettes of conversations with C. P. Butler, former 

observer at the Smithsonian Solar Observatory, Mt. Montezuma, Chile. 

2.2 Barrow 

2.2.1 Facilities 

The only modification of Barrow (BRW) station facilities in 1980 was the 

installation of a thermostat-controlled ventilation system in May. Heating 

and cooling were previously regulated by adjusting individual heaters or 

cranking windows open, which had little effect during long summer days . 

The Naval Arctic Research Laboratory (NARL) started closedown procedures 

in 1980, culminating in the termination of science support activities and the 

10 
departure of University of Alaska staff in October. Operations and maintenance personnel were also reduced as closedown operations progressed, although 

the final phase has not yet been implemented. GMCC staff moved to housing 

provided by the National Weather Service (NWS) in the town of Barrow in July 

and found alternate sources for a ll supplies and services formerly provided by 

NARL, with the exception of station electricity, which is still being supplied 

by NARL. 

2.2.2 Programs 

Programs carried out at BRW are listed in table 4. Comments on some of 

the programs follow. 

Carbon Dioxide 

The continuous analyzer was switched from C02-in-N2 reference gases to 

C02-in-air gases in 1980, with three intercomparisons of C02/N2 and C02/air 

standards being done onsite. Unfortunately, the C02/N2 standards were drained 

while in transit to Scripps for final calibration, necessitating another 

series of runs to infer a final value for the lost tanks. Now our procedure 

for shipping valuable reference tanks is to send the tanks and valve handles 

separately. 

The Cincinnati subzero freezer for freezing water vapor out of samples 

failed in April, causing suspension of the continuous C02 program until a 

new Cryo-Cool freezer arrived in May. 

A second CO2 sampling line was installed in ~!ay. This line, which alternately serves as a quality check on the sampling stack and a ground-level 

sampling line for periods of high CO 2 activity in the tundra, runs on a timeshare basis with the stack. 

A 5-1 glass flask sampling program began in 1980. Pairs of 5-1 flask 

samples are taken twice-monthly to augment the other C02 flask programs. 

ICDAS 

Severe difficulties with the Xerox multiplexor and Wang tape drive 

caused much downtime late in the year. New components and a visit to Barrow 

by some of the Boulder electronic s sta ff so lved most of the problems. 

Lidar 

The lidar hut was repositioned in July to get it out of the winter snowdrift pattern caused by neighboring buildings. System components began arriving in August, but the final parts did not arrive until De cember. Consequently, there were no lidar operations in 1980. 

Total and Surface Ozone 

Barrow'.s Dobson spectrophotometer no. 76 was in Boulder from January to 

May 1980 for calibration and refitting. 

A modernized Dasibi ozone meter was installed in September. 

11 
Table 4.--Summary of sampling programs at Barrow in 1980 

tionitoring program 

Gases 

Carbon dioxide 

Surface ozone 

Ha l oea rbons 

Total ozone 

Aerosols 

Condensation nuclei 

Optical properties 

Vertical distribution 

Solar radiation 

Global spectral irradiance 

Dire ct spectral irradiance 

Turbidity 

Meteorology 

Air temperature 

Relative humidity 

Air pressure 

Wind (speed a nd direction) 

Ground temperature 

Precipitation chemistry 

pH and conduc tivi ty 

Cooperative programs 

Tota l s ur face particulates 

(DOEjEtIL) 

Arctic haze particulates 

(URI) 

Global radiation 

(SRL) 

CO 2 sampling (SID) 

Precipitation gage (Soil 

Conservation Service) 

Carbonaceous particles 

(LBL) 

Halocarbons (DGe) 

Incident and reflected 

radiation (U. of Alaska) 

Instrument 

URAS-2T infrared analyzer 

Glass flask pairs 

5-Q glass flask pairs 

Dasibi ozone meter 

Flask sampl es 

Dobso n spectrophotometer #76 

G.E. eN counter 

Pollack counter 

Four-wavelength nephelometer 

Lidar 

Four Eppley pyranometers 

with Ql, GG22, OGI and 

RCB filters 

Eppley normal incidence 

pyrheliometer with filter 

wheel 

Eppley sun photometer 

Thermistor 

Hy grothermograph 

Dewpoint hygrometer 

Sling psychrometer 

Tra nsducer 

Microbarograph 

Mercurial barometer 

Bendix aerovane 

Thermistor 

Wide-mouth polyet hylene 

collector (samples 

analyzed at MLO) 

Collection of snow o n tundra 

(samples analyzed at MLO) 

High-volume sampl er 

High-volwne sampl ers 

Radon monitors 

Eppley pyranometers 

Temple U. sunburning meter 

Flask samples 

Wyoming shielded precipitation gage 

Hi gh - volume sampl er 

Surface snow samples 

Flask sample s 

Up-down pyranometers 

12 

Sampl ing frequency 

Continuous 

lpairwk- I 

2 pair mo- 1 

Continuous 

1 pair wk- 1 

3 day-' 

Continuous 

Discrete 

Conti nu ous 

Disc rete 

Continuous 

Discre te 

Discrete 

Continuous 

Contin uous 

Continuous 

Discrete 

Continuous 

Continuous 

Discret e 

Continuous 

Continuous 

Discrete 

2 mo- 1 

Continuous 

Continuous 

Discrete 

Continuous 

Continuous 

2 se t s mo- 1 

2 readings mo- 1 

Continuous 

2 mo- 1 

3 fla s ks wk I 

Continuous 
2.2.3 Coopera t ive Programs 

A halocarbon flask sampling program began with the Oregon Graduate 

Center (OGC) in ~Iay. Three flask sampl es are taken per week. 

The University of Rhode Island (URI) radon experiment was t erminated in 

August. 

OGC, Brookhaven National Laboratories, and the National Burea u of Standards ran filters on one of URI's samplers during winter, 1980-81. 

A four-radiometer system, composed of two upward-looking and two downwa rdlooking instruments, was installed by the University of Alaska Geophysical 

Institute in September. 

The Barrow staff began making occasional trips to the neighboring Village 

of Atkas uk , 60 mi SSW of Barrow, to read and record measurements by a Wyoming 

shielded precipitation gage located near there, for the U.S. Soil Co ns ervation 

Service. 

A temporary filter project, to sampl e for HN0 3 , NH3, and S02, was run 

for the National Center for Atmospheric Research (NCAR) from April through 

June. 

2.3 Samoa 

2.3 .1 Facilities 

There were no permanent additions or modifications to the Samoa Observatory (S~IO) facili ties during 1980. However, temporary facility additions 

were made for SEAREX (Sea-Air Exchange program), a planned 1981 project 

sponsored by the National Science Foundation (NSF). The additions consisted 

of a number of small prefab buildings located on ~Iatatula Point, where the 

SEAREX air-sampling experiments will be performed. Five buildings were 

added: four on the point and one on the ridge adjacent to the GMCC remote 

sampling tower. Three of the five buildings will be used for laboratory work 

and two for storage and personnel shelter. Disposition of the buildings 

after completion of the experiments wi ll be de cided later. 

The primary SEAREX facility at Matatula Point consists of two walkup 

towers (Upright Scaffold brand) of 60- and 42-ft heights, used for air and 

precipitation samplings, respectively. All materials for the buildings and 

towers were furnished by SEAREX. In anticipation of the increased electrical 

load from air-sampling pumps, an additional power line was also installed to 

Matatula Point, with its own meter. The SEAREX project will thus be able to 

purchase its own e le ctrical power and not overload the GMCC system and backup 

generator. 

2.3.2 Programs 

All 1980 programs at SMO are summarized in table 5. Additional comments 

follow. 

l3 
Table S.--Summary of sampling programs at Samoa in 1980 

Nonitoring program 

Gases 

Carbon dioxide 

Surface ozone 

Total ozone 

Fluorocarbons 

Aeroso ls 

Condensation nuclei 

Scattering properties 

(surface air) 

Atmospheric turbidity 

Solar Radiation 

Global spectral 

i rradiance 

Direct spectral 

irradiance 

Neteo rology 

Temperature (air) 

Temperature (soil) 

Temperature (dewpoint) 

Relative humidity 

Wind (speed and 

direction) 

Pressure 

Pre c ipitation chemistry 

pH and conductivity 

Cooperative programs 

ALE project--F-ll, F-12, 

N2 0, CHCI 3 , CC1, (OGC) 

CH" CO , CO2 (OGC) 

Flask program--CH3I, 

CH3Cl, CH" CO (OGC) 

Wet- dry deposition--

since ma y 1980 (NADP) 

Wet-dry deposition 

(DOE/EHL) 

Wet depo s ition 

Instrument 

URAS-2T NDIR analyzer 

Evacuated glass flasks 

Electrochemical concentration 

cell 

Dasibi ozone meter 

Dob son spectrophotometer #42 

Flask sampling 

G.E. CN counter 

Pollak CN cou nter 

Four-wavelength nephelometer 

Volz sun photometer 

Four Eppley pyranometers with 

quartz, GG22, OGl, and RGB 

filters 

Eppley NIP with filter wheel 

(OGI, RG2, RG8) 

Eppley NIP/equatorial mount 

combination 

Thermistor 

Thermograph 

Psychrometer 

Nax . -min. thermomete rs 

Thermistor 

thermistor with LiCl dew ce ll 

Hygrothermograph 

Bendix aerovane 

Transducer (capacitance type) 

Microbarograph 

Nercurial barometer 

Orion pH meter 

Beckman conductivity bridge 

Samples s ent to NLO for further 

analysis on ion chromatograph 

HP 5840A ga s chromatograph 

Carl e gas chromatograph 

SS flasks, analyzed at OGC--

3 flasks per set 

HASL wet-dry collector 

HASL wet-dry collector 

Mis co co llector 

14 

Sampling frequency 

Continuolls 

Dis cre te 

Conti nuous 

Co ntinuous 

Discrete 

1 wk- 1 

Conti nuous 

Dis crete 

Offline a ll 

year 

Discre te 

Continuous 

Disc rete 

Continuous 

Co ntinuous 

Continuous 

Dis cre t e 

Discre t e 

Continuous 

Co ntinuous 

Continuous 

Continuous 

Continuous 

Continuous 

Dis cre te 

Disc rete 

h-' 

3 h-' 

wk- 1 

wk -1 

1 mo- 1 

1 mo -1 
The G~ICC group of trace gas and aerosol sensors remained un changed at 

the Samoa stati on during 1980. Absent, however, for the entire year, was the 

four-wavelength nephelometer. It had been returned to the United States for 

installation of a new PM t ube detector that requires no cooling. It is hoped 

that this modification wil l elimina t e t he moistur e problems experienced with 

the older model detector that required cooling. 

A compre hensive C02 flask sampling program was also maintained throughout the year as a check for the GMCC/SMO continuous-a nalyzer air sampl e line 

and also as a means of examining possible effects of excessive wate r vapor, 

characteristic of Samoan ambi ent air, on flask samples sent to Bo ulder. 

2.3 . 3 Cooperative Programs 

In Hay 1980, Samoa GMCC became an NADP collection site, and a weekly 

rain sample plus a bimonthly dry-deposition sample has been sent regularly to 

the Central Analytical Laboratory of ISWS . The EPA Misco collector as well 

as the DOE/EML wet-dry collector will eventually be phased out. 

The OGC gas chromatograph installation was operational a ll year and is 

the only other major cooperative program. In addition, an OGC weekly flask 

sampl ing program was begun t o measure methyl iodide concentra tions . 

2 . 3 . 4 Special Projects 

A comprehensive tracer study of Matatula Point was performed during 

Apri l . F. Shais, professor of chemical engineering at Cali fornia Institute 

of Technology (CIT), was the principal investigator. D. Reible (CIT), R. Cayer 

(URI/SEAREX), and Samoa GMCC personnel assisted in 18 expe riments using 

SF6, smoke flares , and balloons . The purpose of the investigati on was t o 

examine the possible contamina tion effects t hat local vegetation and terrain 

might have on planned SEAREX ope r ations in 1981. Results of the tracer study 

confirmed Cape Iatatula as a very good sampling p l atform. Discussions have 

begun that may possibly res ult in publication of t he tracer experiment results 

as a NOAA Technical tlemorandum. 

2.4 South Pole 

2 . 4 .1 Faciliti es 

A structural defec t in the Clean Air Facility (CAF) at the South Pole 

Observatory (SPO) was discovered i n late 1979. Cross-memb er I-beams were 

found to be deflected more t han the design allowed. Reinforcements were made 

in the 1980-81 summer season. 

Electrical power t o the CAF was adequate. The room hou sing G~ CC equipment, however, was not adequately wired for the load. Additional equipment 

placed on certain ou tlets caused circui t breakers to t rip because the room was 

wired more as living quarters than as a scientific laboratory. 

The CAF was adequately bui lt and i nsulated so that the provided heaters 

maintained an ave ra ge r oom t emper a ture of 21°C. Si nce all t he heaters were 

15 
manually set, outside fluctuations in windspeed 

temperature fluctuations . There appeared to be 

room temperature change and C02 analyzer drift. 

heat would reduce these fluctuations. 

and temperature caused room 

a direct correlation between 

Thermostatically controlled 

The sampling stacks used by GMCC, the University of Maryland, a nd the 

Department of Energy (DOE) , all required cleaning during the winter because of 

snow and frost accumulations. At one time, hi gh winds blowing from grid 3100 

over the inlet of the GMCC gas-sampling stack caused sufficient vacuum force 

t o draw room air up into the stack. 

A humidifi er was used throughout the year to suppress static discharge. 

At no time was static buildup noticed. 

2.4 . 2 Programs 

SPO programs for 1980 are listed in table 6 and briefly described below. 

ICDAS 

The NOVA 1220 and associated equipment ran we l l during the year with only 

minor outages. (The NOVA power supply failed in December 1979.) The Wang 

tape drive failed on October 19, 1980, with a burned-out fixed-reel f i le arm 

sense lamp. 

Modifications to I CDAS included a new NOVA front panel, new Chronolog 

clock, and a revised edition of the basi c operating software (BOSS 79001). 

The revised software was implemented in November 19 79. 

The Deltec uninterruptible power supply was shipped to American Samoa in 

December 1979 . 

Carbon Dioxide 

Continuous measurements of carbon dioxide began on November 18, 1979. 

The program was restarted after bei ng s hut down in November 1978. The same 

reference gases used before this s hutdown were used in the restart. During 

the first few months the program was chara c t erized by a hi gh zero drift rate 

and a need for frequent alignments. After station closing, the analyzer 

settled down and t he program proceeded smoothly. A CO 2-in-air reference tank 

was installed on Marc h 16, 1980, as a surveillance gas. Discrete samp ling by 

flasks conti nued but at a rate of one pair per week. Samples were alternately 

t aken on the CAF roof and through the analyzer system. 

Solar Radiation 

The heater bl ower system worked fairly well in preventing ice buildup on 

t he pyranometer domes. Heavy insulation of t he system prevented heat loss and 

allowed mo re warm air to the domes. 

Calibrations were made once per month on the solar radiation preamplifiers. 

Data were collected to study the effect of therma l gradients on the 

pyranometers' casings and filters caused by heating from the deicing blowers. 

16 
Table 6.--Summary of samp l ing programs at South Pole i n 1980 

tlollitorin8 program 

G(lSf"S 

- Carbon dloxid(> 

Surface ozone 

TOt,l I 07.01W 

F I uoro,,] rbons 

Aero~ 

Condt'/Isation nuclei 

Optical propt'rt les 

Solar radiati on 

~obal spectral irrarl l anct' 

Direct sVec1rai Irradlance 

t!..c!:...£.£..ro~ 

,\ir temperalur(' 

Snow tempt'ra1urc 

Pressure 

Wi'ld (speed ,I nd direction) 

A1mospht're mOis tu re 

content 

~hscel~ous 

Room tt'mp('ratuf(, 

CO~I~e programs 

Carbon dioxidf' (510) 

To l al slirface parllculatf"s 

(atmosphere trac!' m('lals) 

(DOf./EHDA/II/\ SL) 

Turbidity (NOAA/ARI.) 

Carhon-\4 sampling 

(NOMj/\RL) 

Almosplwrlc (Iwmlstry 

(U. of ~Iaryl.lnd ;111.1 lRl) 

flu oroc arhons 

(OGe) 

Ae rosols 

Instrument 

0.5 - £ evacuated glass fl asks, 

hand aspi rated/through analY7.er 

Oasibi ozon(> meter 

Dobson spectrophot ometer 1180 

)OO -m£ st ainless steel 

samp ling cy I i nde rs 

G.r.. CN counter 

Pollak CN counter 

tong-tubed Gardner CN coun ter 

four -... ·a velength nephelometer 

Four Eppley pyrallometers with 

quartz, G622 , OG 1, and 

RGB filters 

Ul tra viole t radlometel' 

NIP 011 t'quatorlal tracker 

Filter ... heel normal incidence 

pyrhel iometer ... ·ith quartz, 

OGI, RG2, and RGB filers 

Th('rmistor (naturally venti -

lated shield) 

TlH'rmiSlor 

Transducer 

~licrob.1rograJlh 

~Ie rcu ry ("0 I umn 

Benuix-Friez aerovall(' and 

recording systf'm 

Dli Pont )D) mOis ture monitor 

Thermistor 

5-1 t'v~cuat ed glass flasks 

Mo lor-driv(,11 r ota ry lobe 

hlo ... er (h igh-volume air 

s;lmp\ing through fil t ers) 

Dual-... ave!cng th slln phot omete r 

I'ressurlz('t! s t('('1 sphert·s 

Illgh-volum(' filters 

S-2 ('v~~uat('d stainless 

sl('I'1 (},{IIIU1('rs 

Sampling frequen cy 

I pal r .... k - I 

Con t inuous 

Discrete 

pair .... k - 1 

pair "k-' 

austral s unun('r 

2 pair .0 -, austral wlnt('r 

CO lltinuolls 

Discre t e, 2 -4 day , Discrete, I day -1 

Continuous 

Continuolls Ju fI ng 

austral sununer 

Con t i nuous during 

austral sununcr 

Cont I nuous du r ing 

austral summe r 

Oi scretc during 

austral s ununer 

Con tinuous 

COlitinuolls 

COll tlnolls 

COlltinuous 

) d., , Continuous 

Co ntlnuolls 

Conti nuous 

2 mo- I (3 flask s 

pt'r s ampl e) 

Continuous (filters 

changed 4 times moo]) 

Ihsc r('te during 

austral surnmC' r 

500 Ib In- 2 ambll"nt air 

day - 1, for 6 days 

C0l1 tl11UOUS 

) timf's t1urlll~ 

,1ustr,,1 sununt'r (J 

1 lasks I'f'r S,llOl'\(') 

Da ta record 

Nov 79-presen t 

Jan 76 - present 

Dc< 63-present 

Jan 77 -Dec 79 

Jan 80-present 

Jan 80-I'I'esell t 

Joo 74-pres('nt 

Jan 74-presellt 

Jan 74 -;\ug 80 

Jan 79 -J.1n 80 

Feb 74-prescllt 

Feb 74 - present 

Oct 75-prcsent 

Jan 77-pl"ese ll1 

~Ia r 77-prcsent 

Jul 77-presen t 

De< 75 -present 

feb 80-p res en t 

J .e SO-present 

DC< 75- I)resen t 

~Ia r 77-pre5('n t 

Jul 78- present 

1,)57-pr('sen1 

tlay 70 -prest'llt 

J,111 74-pr('sf'lIt 

Jan 74-I'I'eS('lIt 

Jan 7') -prf's('n t 

1980 

The four-wavelengt h nephelometer was s hippe d to Bou l der in Ja nuary 1980 

for upgrad in g . Observations with the long-tube d Gardner CN counter stoppe d i n 

November 1980 beca use of poor performan ce . Co nti nuous aerosol mea s urements 

wi t h the G.E. CN counter were made all year and were checked daily with t he 

Pollak CN cou nte r. 

Surface Ozone 

Surface ozone was meas ured usi ng a Da sibi ozone meter . ~Ieasur ment s with 

Lhe ECC meter were discontinued the previous year . No maj or problems occurred. The NEC-lOOO ozone generator fai l ed on two occasions. 

17 
The Dasibi manual recommends inspection of the absorption tubes once 

every 2 months, and cleaning if necessary. Regular cleaning of the tubes, 

regardless of the inspection, reduced meter noise significantly. 

Halocarbons 

Sampling freque ncy was once per wee k durin g the austral summ er as i n 

previous years. Sampl ing in the winter was changed from once per mont h to 

twice per month. Flasks for use in the winter were pressurized with outside 

air and stored. 

Ne t.eoro l ogy 

The GNCC wind sensor was rea ligned to a north-south line surveyed by 

USGS. The system was overhauled at the same time. 

A microbarograph and a mercury column were received in early 1980. These 

provided a backup and check on the press ur e tra nsducer. 

The Du Pont 303 moistur e monitor malfunctioned between February 14 and 

Novemb er 9, 1980. At that time, the data were fo und to be seve ral orders of 

magnitude low. The problem was co rrec t ed by replacing the sensor cell. 

2.4 . 3 Special Project 

A specia l project involving processing of GNCC data tapes was carried out 

at SPO. Fortran programs were wri tten to enable SPO, for the first time, to 

examine the tapes writLeIl by ICDAS. These programs print and plot data in 

various ICDAS channe l s for data quality che cks. Vi s ual checks of the data by 

means of graph s help ensure that the instruments and ICDAS are performing 

properly. Thes e programs are rudimentary, but ca n be expanded for more 

sophisticated use. 

The computer system at SPO i s composed of two 32K and one 16K HewlettPac kard minicomputers . Peripherals include five tape drives, three terminals, 

two line printers, and one x-y plotte r . The programing languages available on 

the system are Basic and Fo rtran IV . 

During the winter- over period, six separate Fortran programs were written 

to read and print composite l y either the six solar radiation channels, t he six 

meteorological channels, t he res ultant windspeed and wi nd direction , or the 

separate channels of carbon dioxide, s urface ozone, and aerosols. Plots of 

data in the various channels are made t hrough a different program. For convenience, a program was written to pa ck hourly averages from the GflCC data 

tape onto a separate tape. One tape holds nea rly I year of hourl y averaged 

data. All programs that read directly from the GN CC data tape make use of a 

routine, written by W. Smythe of UCLA, whi ch converts Data Genera l floating 

point numbers to HP floating point numbers . 

In the future, t he SPO system could be used to provide many additional 

services: for examp l e , to perform statistical calculations, to provide tapecopying facilities to ensure against data l oss , and to maintain detailed 

records of instrument performance . 

18 
3. CONTINUING GNCC PROGRMIS 

3. 1 Carbon Dioxide 

3.1.1 Analyzer CO. Neasurements 

CO. measurements made with continuously operating nondispersive infra red 

gas analyzers were continued during 1980 at the four mlcc sta tions. Data 

acquisition a nd processing pro cedures r emained identical to those used in the 

past. The complete reco r d (including 1980 data) of provisional mean monthly 

C02 mol e fractions for BRW, MLO, SMO, a nd SPO is given in table 7 . Plots of 

the data are shown in fig. 1. 

The data are presented in the WMO 1974 CO.-in-air mole fra c tion scale, 

i.e., with tentative pressure-broadening corrections applied. Final corrections to the data are yet to be mad e and "'ill be ba sed on reprocessing of 

the data, using improved working-reference-gas concentration values and applications of more precise press ure - broadening correc tions. Additional corrections to the SNO data will be needed to account for air line sampling problems that were experienced at the station in the past, caused by the high moisture content of the Samoa a tmos phere. 

Table 7.--Provisional mean monthly CO2 mol e fractio ns 

in ppm for Barrow, Mauna Loa, Samoa , and South Pole 

Yea r Jon reb H" Ap' H.y Jun Jul Aug Sep Oct Nov De< 

Sa rrow 

19 /J 324.4 )22.7 325.7 330.3 334.1 334.5 

19 74 339. I 336 . 8 337.6 338.9 337.4 336.4 331.0 325.5 326.4 330.1 333.3 336.1 

1975 338.5 338.7 338.2 338.5 339.6 336.1 329.9 324.7 325.8 330.2 335.3 337.0 

1976 337.6 337 . 8 338.8 338.9 338.2 337. I 331. 3 323 . 8 325. I 330. 334.2 336.5 

1977 336.7 3)6.9 338.2 339. I 339.3 337.8 330.1 326 . 8 328.0 332 334.9 338.8 

1978 339 , )40.2 341.7 34 1.1 340.8 339.6 332.0 328 . 3 328.6 332 2 338. 1 338.6 

1979 339.4 340.6 341 .7 341.4 341.9 340.9 332 .4 327.4 329.4 332 3 331 . 6 340.7 

1980 34 1.1 341.9 342.9 343.5 343 . I 342.7 336.5 331.7 33 1. 3 338.1 340 .4 342 .9 

Mauna Loa 

1974 332.9 331.8 330.5 328 . 5 326.9 326 8 328.0 329.3 

19 75 330.5 33 1. 2 331.9 333.0 333.6 333.0 33 1.3 329.4 328.1 328 , 329.4 330.7 

1976 33 1.6 332.5 333.3 334.6 334.8 334.2 332.5 330.3 328.8 328 6 329.9 330.4 

1977 332.7 333.1 334.7 335.9 336.6 336.0 334.4 332.3 331.1 331 .2 332.6 333.9 

1978 335. I 335.3 336.4 337 . 8 337.9 337.9 336.3 33' 2 332.0 332 , 333.7 334.8 

1979 336.0 336.5 337.9 338.5 339.0 339. I 337.4 335 . 2 333.8 334 3 335 .1 336.4 

1980 337 .6 337.9 339.6 340.4 341.1 340.8 338.7 336 . 8 335.1 335.2 336.4 337.5 

Samoa 

1976 333.4 333 . 0 332.5 332.4 331 .7 332 .2 332 . I 332.2 332.4 332.5 333.1 333.3 

1977 333.0 332 .5 333.3 333.3 333.6 334.6 334.2 334.1 333.8 335.0 335.2 

1978 335.6 335.4 335.8 335.4 335.7 335.2 335.7 

1979 335.7 336.6 336.0 336.4 336.7 336.7 336.6 336 .9 337.0 337.3 

1980 338.1 338.1 338.1 337.8 338.3 338.0 338 .0 337.4 337.3 337.4 337.8 338.6 

Sout h Pole 

1975 329.1 329 . 2 329.3 328.9 328.6 329.1 329.8 330.5 331.0 33 1.3 330.5 329.4 

1976 329.2 328.8 328.7 328.6 328.7 328.9 329.3 329.8 330.4 330.5 330 . 6 330.5 

. 1977 330.0 330.9 330.7 330.8 330.9 331.1 33 1.3 331.7 332.1 332.4 332.4 332. 1 

1978 33 1 .8 331.9 332.6 333.1 333.1 333.5 333.9 334.8 335.4 335.4 335.2 0.0 

1979 

1980 335.2 335. 1 335. I 334.9 335. t 335.4 335.9 336.2 336.5 337. 1 337.0 336.7 

19 
E 

0. 

0. 

c 

N 

0 

() 

345 

340 

335 

330 

325 

__ SRW 

0------<:> MLO 

SMO 

- SPO 

32 L-~19~7~3~~9~7~4~--1~97~5~--1~97-6--L-1~9-7-7-L-1~9~7~8~--19-7-9~--1980~~--1~98-1~ 

Year 

Figure 1.--Provisional mean monthly C02 mol e fractions for GMCC observatories. 

Relative errors in the data are estimated to be less than 1 ppm, except 

for the first 3 years of the Barrow data and sporadic intervals of the South 

Pole data where pressure-broadening corrections have been estimated only 

roughly. Systematic errors are believed to be generally less than ±1 ppm when 

referred to an absolute C02 mole fraction calibration scale. 

3.1 . 2 Flask Sample C02 Measurements 

The GMCC C02 flask sampling program was expanded in 1980 to include three 

new stations, viz., Azores (Terceira Island, North Atlantic), Mould Bay 

(N.W.T.), and Seychelles (tlahe Island, Indian Ocean). A list of stations 

operating in 1980 is given below. Detailed information about these stations, 

e . g., location, siting, and cooperative agencies, is provided on page 19 of 

the GMCC No.8 Sununary Report for 1979 (Herbert, 1980). 

1980 C02 flask sampling station network 

American Samoa, S. Pac. 

Amsterdam Is., Ind . Dc. 

Ascension Is., S. Atl. 

Azores (Terceira Is.), N. Atl. 

Cape Kumukahi, Hawaii 

Cold Bay, Alaska 

Cosmo s , Peru 

Guam (Marianas Is.), N. Pac. 

Key Biscayne, Fla. 

20 

Mauna Loa, Hawaii 

Mould Bay, N.W.T . 

Niwot Ridge, Colo. 

Ocean Station M, N. Atl. 

Palmer Station (Anvers Is.) , Ant. 

Pt. Barrow, Alaska 

Pt . Six Mountain, Mont. 

Seychelles (Mahe Is.), Ind. Dc. 

South Pole, Ant . 
Plots of 1979 and 1980 provisional CO 2 mole fractions , expressed in the 

1974 ~IO C02-in-air mole fraction scale, are shown in fig. 2. Here, pair sample C02 values agreeing to within 1 ppm ha ve been averaged; for pair samples 

differing by more than 1 ppm, the lower value has been plotted. Some available data have been excluded from the plots following subjective analysis because of sampling problems experienced particularly in 1980. 

These problems resulted primarily from contamination of the glass flasks 

with silicone grease residue following annealing of the flasks for c leaning. 

Additional problems were experienced when contamination occurred at times 

during flask evacuation and when C02-rich air leaked occasionally into evacuated flasks through improperly greased stopcocks. To avoid these sampling 

problems, the collection of ambient pressure samples in evacuated flasks i s 

currently being phased out. Instead, a method of collecting pressurized air 

samples in reference-gas-filled flasks is being introduced. Flushing and filling of the flasks during sampl e coll ection is accomplished with a portable, 

mechanized pump apparatus. The flask stopcocks are , furthermore, now greased 

with Apiezon-N grease. 

A prominent feature of the data plots of fig. 2 is the decrease in the amplitude of the C02 annual cycle in the Northern Hemisphere, with far-northern 

peak-to-peak values of approximately 15 ppm decreasing to essentially 0 ppm at 

the Equator. In the Southern Hemisphere, peak-to-peak annual cycle amplitudes 

of about 1 ppm are discernible . 

Provisional 1979 annual mean, winter (January through Narch), and s ummer 

(July through Septemb er) CO 2 latitudinal gradients have been derived from the 

1979 and 1980 flask sample data (see fig. 3). Note the large drawdown of CO 2 

by growing plants in the Northern Hemisphere SURilller . The annual mean gradient 

plot of fig. 3 exhibits several interesting features . The pole-to-pole CO 2 

difference is slightly greater than 3 ppm. Also, several maxima appear in the 

distribution. One occurs in the Northern Hemisphere north of approximately 

40 0 N, which is where most fossil fuel CO 2 is released into the atmosphe re. A 

second occurs at the Equator. A third maximum, possibly representing a Southern Hemisphere CO 2 source, is evident at about 65°S latitude. The existence of 

this maximum has been inferred from highly tenuous CO 2 observations made at 

Palmer Station, Antarctica. Additional analyses of the data as well as C02 

measurements in middle-to-high latitudes of the Southern Hemisphere are needed 

to verify tha t this ma ximum is rea 1. 

21 
o 

~";:O~U~;oO;..;:B;:AY.:-"-C,,A:;.N'TA::;O::;Ao..,~~~7;:6:;:.;N PO I NT S I X Mr_. MONTA NA 

o 0 

00 

o 

<IN KEY BISCAYNE. fLORIDA 

o 

o 

o 

",0 

26 

NI WOT RIIX:E, COLORA-IX) 40N "'''UNA LOA . HAWA II 20N 

::< 

a. 

a. 

zO 

O~ 

cUo 

«~ 

0:: " 

"-

W g 

, " o 

fERCEIRA IS .. AZORES 

1979 1980 1979 

Sf CROI X, AM VIRG I N IS 18N ASCENS I 0/11 IS 

o 

::E ~ GUAM. MARIANAS IS. 13N COSMOS, PERU 

" N 

o 

U 

o 

.~ 

o 

o 

39N CAPE KUt.lUKAHI. HAWAII 20 

1980 1979 1980 

BS AMSTERDAM I S , 

• 'I; 

o 

125 PALMER STATI ON . ANTARCTI C G5S 

5S CAPE .',j ,\TATULA. AM SAMOA 14S SOUT H POLE. ANTARCTI CA 90S 

19?9 1980 1979 1980 1979 1980 

Figure 2.--Flask sample C02 mole fractions for stations in the GMCC C02 

station network. 

22 
., 

.0 

a. 

.eo 

0 

N 

z 

360f::' , , , " I I : 

~ BAW : 

340 f:: : . .. : 

320~.' ,", '.: ', :",""': ,,:: "" • .' • ,,,:,,:: .. . ": 

:::~ ~ .. , :' : .N~A . ,'. ,". '." :' . •.... , ">' " :,".' 

320 

360 

340 

320 

f:: MLO 

:: 

f= :: 

f:: , .: :"'::': ':'::I: :: ' " . :, ... , .. ' . , :.:n 

1--. :: 

360 = :: 

: SMO : 

340 - :: ;::. :.1 , .. ' ., :: .. . ,.: " .: ••• : ~ I • I • • .' .. ; : :::: - 320 

360 : 

SPO 

:: 

= 

:: 

340 

320 

= -

;::. ,.:. "'.;" .. ': 

"'I , , 1 , , , , , . ' .. ',' ":: 

J FMAM J J AS OND 

Figure 1S.--N20 s ample data obtained 

during 1979 at BRW, Niwot Ridge, MLO, 

SMO, and SPO. 

3.7 Surface Aerosols 

The routine GMCC surface aerosol program for 1979 included the measurement of 

condensation nuclei concentration and volumetric light scattering at BRW, MLO, 

SMO, and SPO. Condensation nuclei concentration is measured continuously with a 

modified version of the G.E. condensation nuclei counter at a ll four sites. A 

Pollak (manually operated) condensation nuclei counter is located at each site to 

serve as a secondary standard and provide calibration points for the automatic 

nuclei counter. A four-wavelength nephelometer was operating at each site during 

1979 . This report will present the first light s cattering data acquired at SPO. 

The calibration of the automatic nuclei counter is checked daily by comparison with the Pollak nuclei counter. If necessary, the automatic nuclei counter is 

forced to agree with the Pollak counter. The complete calibration procedure and 

scaling of the data are described by Bodhaine and Murphy (1980). The fourwavelength nephelometers are calibrated by filling them with carbon dioxide gas at 

2-mo intervals. The output of the instrument can then be adjusted to give the 

known volumetric scattering coefficients of carbon dioxide. Bodhaine (1979) gives 

details of the theory and practice of nephelometer calibration and the latest 

recommended values of the scattering coefficients of air, argon, carbon dioxide, 

and Freon-12. 

35 
3 . 7 . 1 Ba r row 

Pollak counter SN16 was operated routinely throughout 1979 at BRW. The 

automatic nuclei counter had several brief periods of downtime on DOY 1-3, 14-15, 

123-126, 164-165, 176, 178, and 196-200, with acceptable data for 94% of the hours 

of the year. The principal cause of downtime was a problem with the high voltage 

power supply. All data were recorded on magnetic tape and a backup chart recorder . 

The Barrow nephelometer SN105 operated properly during 1979 except for DOY 84-89, 

with acceptable data for 96% of the hours of the year. The principal cause of 

downtime was the weekly relative calibration; however, the instrument was inadvertently left in the test mode, causing the DOY 84-89 downtime. 

3.7 . 2 Mauna Loa 

The ~ILO Pollak counter SN13, the GMCC reference instrument, was operated 

daily throughout 1979 to provide a record of Pollak counter observations and 

routine calibration for the automatic nuclei counter. The automatic nuclei counter 

produced acceptable data during 93% of the year. Most of the downtime (DOY 80-94) 

resulted from electronic problems caused by a lightning strike at the station . 

The MLO nephelometer produced acceptable data for 95% of the year. The 

lightning strike caused downtime during DOY 80-87; however, channel one of the 

nephelometer experienced an intermittent problem throughout the year (caused by an 

AD540J operational amplifier) and produced good data for only 77% of Lhe ye~L . 

All data were recorded on magnetic tape and a backup chart recorder. 

3.7.3 Samoa 

Pollak counter SN20 operated routinely at SMO during 1979 . The automatic 

nuclei counter also operated properly throughout the year but because of numerous 

power outages produced data for only 95% of the year. 

The SMO four-wavelength nephelometer, after being in Boulder for repair, was 

again installed at SMO on DOY 87. However, the instrument developed an intermittent electronic problem and was shipped to the University of Washington for modification and repair on DOY 270. Data were acceptable for approximately 26% of the 

year . All data were recorded on magnetic tape and a ba c kup chart recorder. 

3.7.4 South Pole 

SPO Pollak counter SN15 was operated twice daily with no problems during 

1979. At the time of each observation, meteorological variables are recorded on 

the observation form. These observations are subsequently keypunched and are 

available along with condensation nuclei concentration in the Pollak counter data 

file. The automatic nuclei counter operated routinely for the entire year producing acceptable data for an astounding 99% of the year. 

A four-wavelength nephelometer (SN107) was installed at SPO on DOY 13 and 

operated satisfactorily until DOY 317 when electronic problems interrupted the 

data record. Because of long recovery times following power interruptions and 

relative calibrations, only 68% of the data were acceptable for the year. The 

instrument was shipped back to Boulder in December 1979. All data were recorded 

on magnetic tape and a backup chart recorder. 

36 
, 

I - 4 

- 5 

-6 3 

- 7 2 

~;gnm 

_6t

I = ~~~g-=--- 'E #::=::::: ~ 7 

! - 7 I ; 

.'3 - 4 [ ~~~ "'-.. -.1450 nm g' 

r~ ~ -5 _s_am_o_a~ ____ 5_5_0 _____ J2 

- 7 _______ ~550 

700 

850 

_6

t 

450 nm 

- 8 South Pole 

t I I I I I I I I I 

J F M A M J A S ON D 

3 .7. 5 Data Analysis 

Figure l6.--Light scattering (bsp) and 

condensa tion nuclei (N) data for all 

GMCC sta tions for 1979. Monthly geometric means were calculated using a ll 

data for BRW, SMO, and SPO, and 0000-

0800 LST data for MLO. 

Routine aerosol data analysis continues as described in previous GMCC Summary 

Reports . Observer notes and chart records are perused when rece ived to verify 

instrument performance and data quality . Monthly tapes constructed by the Data 

Acquisition and Management Group are accessed and stripped of aerosol data t o 

produce a f ile of hourly means and a graphic display of 10-min means. At this 

time the chart record, 10-min mean graphics, and the ob server notes are consulted 

so that a decision can be made as to when the instruments were opera ting properly 

and missing computer data may be filled in from the chart recorder data. Finally, 

data qua lity is eva luated, data are scaled, and a file of all acceptable data is 

constructed. All data are available from GMCC in computer printout, microfiche, 

magnetic tape, or graphics in groups of 10 days per page , 3 months per page, or 1 

year per page. The graphics can be presented using hourly means or daily means. 

3.7 . 6 Discussion of Selected Data 

Light scattering and condensation nuclei data for 1979 for all stations are 

presented in fig. 16. All available data were us ed to calculate monthly geometric 

37 
means except for MLO for whi ch only data from 0000-0800 LST were used, to avoid 

possible contamination from the upslope winds. 

The Barrow light scattering data exhibit the same seasona l trend as in the 

past, with the Arctic haze event i n March exceeding 10- 5 m- 1 and a minimum in June 

approximate l y an order of magnitude sma ller. These curves c l osely follow the 

seasonal sulfate trend given by Rahn and McCaffrey (1980b), including the small 

peak in December preceeding the larger peak in ~!arch. Condensa tion nuclei data 

also show a strong spring peak exceeding 500 cm- 3 and a second peak in July, 

caused primarily by small particles since only a small peak in light scattering is 

seen in July . This s ummer peak occurs more often in August but i s nevertheless 

seen every year in the Barrow aerosol data. 

To identify local sources of contamination in the vicinity of Barrow, Bodhaine 

et al. (1981) examined the distribution of condensation nuclei (CN) concentration 

as a function of surface wind direction. Figure 17 gives t he mean CN concentration (so lid line) calculated from hourly data on a 36-point wi nd rose for the years 

1977 and 1978 at Barrow. The pooled standard deviations calculated from I-mi n 

data are also given (dashed line). Winds from the west clearly bring conditions 

of high nuclei concentration and high variability. Possible loca l pollution 

sources at Barrow, as determined by T. DeFoor (Barrow station chief in 1978-7 9) 

are s hown in fig. 18. The sources to the west of the station coincide with the 

major peaks of CN concentration shown in fig. 17. Further , the gas well located 

to the southea st of the station appears to be a fairly constant source in fi g. 17. 

For comparison, a map of the Barrow area may be found in m!CC Summary Report 1973, 

p. 8. 

w 

HUCU:' 

ow - 3 

''''" 

BARROW 

N 

s 

so (lot) 

E 

,m TOTAL HOU~ 

w 

HUCUI 

ow -, 

''''" 

BARROW 

jI, ..... . 

N 

s 

SD (Joe) 

.' 

E 

,m TOTAL HOU~ 

Figure 17.--Geometric mean condensation nuclei concentration (so l id lines) as a 

funct ion of wind direction plotted on a 36-point windrose for BRW during 1977 

(left) and 1978 (right) . The dashed lines give pooled standard deviations calculated from I-min data to give a measure of nuclei variability as a function of 

wind direction . 

38 
o , 

. .,Figure 18.--Locations of possible local 

pollution sources relative to BRW GMCC 

site. 

Figure 19 presents a 36-point wind rose for aerosol light scattering (550 nrn) 

for 1978 and for March 1978 at BRW. Local pollution episodes apparently do not 

affect light scattering measurements significantly because the instrument responds 

primarily to particles in the 0.1 ~m <r<1. 0 ~m size range and local pollution 

episodes consist primarily of smaller particles. The bars at the center of each 

graph in fig. 19 give the wind frequency for each direction interval. Winds 

obviously have an easterly component most of the time. 

~lLO light scattering data s hown in fig. 16 exhibit the same annual cycle seen 

in previous years. The spring maximum is nearly an order of magnitude higher than 

the clear winter values. The CN data for Mauna Loa again do not show an obvious 

annual cycle although they appear to follow the light scattering data in a qualitative sense. 

Samoa light scattering and condensation nuclei data continue at about the 

same levels with no obvious seasonal or long term trends. 

The first light scattering data for SPO were obtained during the austral 

winter 1979. These data, presented at the bottom of fig. 16, were surprising 

because the minimum appears in late April and early May unlike the condensation 

nuclei mini mum that appears in June and July . This difference results because the 

nephelometer responds primarily to particles in the size range 0.1 ~m<r<1.0 ~m 

whereas the nuclei counter also responds to the smaller particles. The winter 

months apparently are dominated by episodes when sea salt aerosols are transported 

inland by storms whereas the summer months are dominated by crustal aerosols (see 

Zoller's summary, p. 93, in ~lendonca , 1979). Since the sea salt particles lie in 

a larger size· range, smaller numbers can dominate the light scattering in the 

winter, with the transition in April and May. 

The large peak in light scattering in August tends to dominate the trace for 

the whole year. This event can be seen more clearly in fig. 20, which gives daily 

geometric means of both light scattering and eN concentration for the entire year 

1979 . The event began on 31 July and lasted for about 5 days, reaching a maximum 

39 
IV 

WIND fREQ 

, 

~ 

BARROW 

' 0 

N 

s 

asp " ., 

E 

.. '" TOTAL OU ~ 

IV 

'lIND rREQ 

, 

~ 

BARROW 

'0 

N 

s 

asp " ., 

E 

WA R IIns 

TOTAL HOU~II 

Figure 19.--Windroses showing the geometric mean aerosol light scattering (solid) 

and wind frequency (center bars) as a function of wind direction for 1978 (left) 

and March 1978 (right) at BRW. 

-

~ . . 

• 

~ 

~ " u 

z 

~ 

0 

~ 

A[ROSOL DATA fOR SOUTH POLE 

JAN f EB MA R APR MA Y JUN JUL AUG S[P OCT NOV aEC 

~ 1 ltv. ') ,M! 1/ I:~-~ 1& t.J\ ~ ~ "' . I .... .' .' . . ,'. ' 0' '. , 

'. . ' ','(\ . "', " .- " I, .-' 

_ _ _ MY _ a u _ = 

MONTH or THE YEAR 1979 

n 

~ 

u 

z 

~ 

0 

~ 

Figure 20.--Daily geometric mean condensation nuclei concentration (bottom), 

four-wavelength aerosol light scattering (middle), and Angstrom exponent (top) 

for 1979 at South Pole. The order of the four data channels is shown in fig. 16. 

The Angstrom exponent was calculated from the 550-nm and 700-nm light scatter ing 

data. 

40 
of about 10-~ m- 1 for the 550-nm channel . If the relation suggested by Waggoner 

a nd Weiss (1980) is used, this corresponds to a mass loading of about 3.2 ~g m- 3 

at the peak of the event . A Nuclepore filter sample of the aerosol in this event 

was obtained by J. Bortniak, chief of the program that year. Subsequent analysis 

of the sample by Parungo et al. (1981), using scanning electron microscopy and Xra y dispersive analysis, showed that the aerosol was mostly sea salt with larger 

si zes than other aerosol samples taken during the year. Bodhaine and Bortniak 

(1 981) have discussed this event in more detail. 

The SPO condensation nuclei record continues as in previous years. Murp hy 

and Bodhaine (1980) have p resented a detailed description of all CN meas u reme nts 

at SPO. 

3.8 Solar Radiation Measurements 

Solar irradiance measuring continued at all four baseline stations during 

19 79, as an integral part of G~lCC's long term benchmark parameter monitoring. 

Discrete normal incidence measurements, plus global irradiance and normal incidence 

continuous measurements, constitute the program. The measuring instruments that 

have composed the basic station set since 1975-76 are four Eppley global pyranome t ers with quartz, GG-22, OG-1, and RG-8 Schott glass hemispheric filter domes, an 

Epp ley UV pyranometer (excluding SMO) with diffusing disk, an Eppley normal incidence pyheliometer (NIP) mounted on a solar tracker (excluding BRW) , and a second 

Epp l ey NIP with quartz, OG-1, RG-2, and RG-8 Schott glass filter windows on a 

rotating wheel. Data from the pyranometers and tracking NIP constitute t he continuous program, and discrete measuring is done with the filter wheel NIP. The 

vario us filters on both the pyranometers and the NIP divide the solar spectrum 

into narrow bandpass regions. Table 15 gives the wavelengths of the mean windows 

o f transmittance. 

3.8.1 Data Acquisition and Verification 

NOVA minicomputers at the four baseline stations acquire the solar radiation 

da t a, with analog strip chart recorders providing secondary acquisition capabil it ies. The continuously measuring instruments send milivolt data signals every 

s econd into calibrated amplifiers, before digitization and preliminary online 

Table 15.--Windows of measurements for quartz and Schott glass cutoff filters* 

Filter 

Quartz 

GG-22 

OG-1 

RG-2 

RG-8 

UV 

Wavelength window ~m ) 

0.28-3 . 0 

0.39-3.0 

0.53-3.0 

0.63-3.0 

0.695-3.0 

0.295-0.385 

"'Transmittances can vary slightly with ambient temperature changes and different 

fi l ter production characteristics. 

41 
processing. Nonthly calibration checks verify amplifier accuracy. Only amplified 

voltages are recorded on chart. Nagnetic tape records both I-min voltage sums and 

hourly irradiance values (miliwatts/square centimeter). Data reformating, editing , 

and final offline processing occur in Boulder. The processing procedures take 

into account small scale amplifier performance changes, documented conditions s uch 

as dome obstructions or distinctive atmospheric phenomena, and instrument or data 

acquisition system malfunctions. The fina l archived continuous pyranometer data 

are 2-min integrals expressed in kilojoules per square meter, on the absolute 

radiation scale, as determined by the Davos, Switzerland, pyheliometric intercomparisons of October 1975. Table 16 lists global radiation data archived with the 

National Climati c Center, Ashevill e, North Caro lina , during 1979 and early 1980. 

Hourly integral tables and 2-min average global radiation microfilm plots are 

currently maintained in Boulder. 

The GNCC Acquisition and Data Nanagement Group maintains the unedited continuous NIP voltage and irradiance data on t he monthly station tapes they create, 

because no formalized processing routine has been developed. Punch card files of 

discrete NIP filter wheel measu rements along with the correspond i ng optical air 

ma ss values are a l so maintained in Boulder. 

Table 16.--Global so l ar irradiance data archived during 1979 

Station Tape no . Time period 

lLO A79208 Jan-Jun 19 78 

SNO A79222 Jan-Jun 1978 

BRW A80036 Jan-Jun 1978 

SPO A80075 Jan-Dec 1978 

3 .8 .2 I nstrument Calibration History 

All field so l ar radiation instruments are calibrated by intercomparison with 

Boulder working standard instruments . At approximately l-yr intervals the instruments a r e field l oca t ed so the intercomparisons can be performed. Field instrument instability or degrading bandpass filters, which are age or exposure dependent, as seen i n annual standard to station instrument output ratio changes, can be 

seen in a ca l ibration result time series. 

The standard a nd fie l d gl obal pyranometer intercomparison methodology involves putting the standard instrument online with a calibrated amp lifier, simult aneous to the online station set. The i nstruments are l eft online together for a 

given time period, so that they encounter all the station's regional synoptic 

conditions. Nean ra t ios (standard quartz/ station quartz and station filter domed/ 

standard quartz) are then computed using tabulated hourly instrument irradia nce 

values. Repeating this procedure annually reveals filter dome transmission or 

station instrument characteristic changes. We assume that the standard instrument, 

because it is used infrequently, shows no year-to-year sensing changes. Table 17 

is a compilation of field pyra nometer calibration data over a 4-yr period. SNO 

intercomparison da t a reveal noticeable filter dome degrading and transmission 

reduc ing, probably because of the corrosive marine e nvironment. The S~(O station 

quartz pyranometer s hows a 2.55% degrading output over 3 years. This is not 

42 
Table 17 . --1 977-1980 field pyranomeler cal ibra lioll lesLs 

SLd. IllS. Cal. call . Test ins. C, I COil. Response Di ff. Response 

SUI li a!] D.He se rial no. (mV mW- 1 cm- 2 ) serial no . (mV mW- 1 cm- 2 ) std./test (%) test/std. 

m.o 1/26-1 /3 1/77 10155 0 0725 12616 0.0794 0.965 1 3.49 

10155 0 0725 10151 0.0695 0 9903(GG- 22) 

10155 0.0725 10152 0.0735 O. 7846(OG-I ) 

10155 0.0725 10153 0.0767 0 S832( 8G- 8) 

NLO 6/19 - 7/1 1/78 126 17 0.0810 12616 0.0794 1.0041 - 0 41 

12617 O.OSlO 12560 0.0970 0.9864 I. 36 

12617 O.OSIO 1015 1 0.0695 0.9422(GG-22) 

12617 0 OS lO 10152 0.0735 0 . 7309(OG-I) 

12617 0.OS10 101 53 0.0767 0.S308(8G -8) 

m.o 5/16- 5/3 1/79 126 17 0.OS 10 126 16 0.0794 1.0091 - 0 91 

12617 O.OSlO 12502 0.0952 0.97S5 2. 15 

1261 7 O.OSIO 101 5 1 0.0695 0.9S39(GG- 22) 

12617 O.OSIO 101 52 0.0735 0.7450(OG-l) 

NLO 1/30-2/1 /80 1261 7 O.OSIO 12616 0.0794 1.00lS - 0.18 

12617 0.OS10 10151 0.0695 0.9631(GG-22) 

12617 O.OSIO 10152 0.0735 0.737S(OG- I) 

12617 O.OSIO 1015 3 0.0767 o. S334 (8G-8) 

BRW S/2-S/6/77 10155 0.0725 12263 0 .0956 0.9969 0.81 

10155 0.0725 12265 0 09S3 0.9025(GG-22) 

10155 0.0725 12 264 O. 1051 0.6S ll(OG- I) 

10155 0.0725 12267 0 0965 0.4697(RG-8) 

BRW 4/29- S/9/79 12617 0.0810 12263 0 0956 1.0145 -1. 45 

12617 O.OSIO 12265 0 09S3 0.9043(GG- 22 ) 

12617 O.OSIO 12264 O. 1051 0.6930(OG-I) 

S~IO 7/19- 8/6/78 12617 O.OS IO 12273 0 0927 1.0100 -1. 00 

12617 O.OS IO 122 74 0 0963 0 9284 (GG-22) 

12617 O.OB IO 15347 O. 1048 O. 733S (OG- I ) 

12617 O.OSIO 15348 0. 1047 0 4984(8G- 8) 

S~IO 6/12-7/2/79 12617 0.OS 10 12273 0.0927 1.02 16 - 2.16 

12617 O.OS IO 12274 0.0963 0 9270(GG- 22) 

12617 0.0810 15347 O. 1048 0 728S(OG- I ) 

12617 0.0810 15348 o. 1047 0 4998(8G-8) 

SPO 1/21-1/23/S0 12617 O.OB IO 12273 0 0927 1.0343 - 3.43 

12617 0.08 10 12274 0.0963 0.912 1(GG- 22) 

1261 7 0.0810 15347 0.104B 0.7034(OG-I ) 

1261 7 0.0810 1534S 0.1047 0.46S8(8G- 8) 

S~lO 1/7 -1 /9/77 126 17 0.0810 12271 0.1072 0.9905 0.95 

12617 0.0810 12268 0.1028 0 . 9 144(GG-22) 

12617 0 . 0810 12 269 0.1036 0.7080(OG-1) 

12617 0.0810 12270 0.0978 0.S2S6(8G-8) 

SPO 1/1-1 /10/78 12617 0.08 10 12271 0.1072 0.9961 0 . 39 

126 17 0.OS10 12268 O. 1028 0.9368(GG- 22) 

12617 0.0810 12269 0.1036 0.7394(OG-l) 

12617 0.0810 12270 0.0978 o .531O(RG-S) 

SPO 1/11-1/13/80 12617 0 08 10 12271 0.1072 0.9870 I. 30 

12617 0 08 10 12268 0.1028 0.9208(GG- 22) 

12617 0 08 10 12269 0.1036 0.7080(OG- 1) 

12617 0 08 10 12270 0.0978 0.4990(RG- 8) 

considered excessive. All other station data s how good stability over the listed 

time periods. 

Pyrheliometer ca libration is essentially a simultaneous standard and station 

instrument mea surement, using their respective quartz windows, under the same 

atmospheric conditions , assuming the same stable standard instrument as with the 

pyranometer calibration procedure. Intercomparisons are taken only under clear 

observing conditions. The two instruments are aligned side by side, with their 

plugs connected to a toggle sw itch, which is itself connected to a voltmeter . 

After milivolt instrument outputs are taken, irradiance values are computed and a 

mean ratio (standard quartz/station quartz) ca l culated. Table 18 is a compilation 

of pyrheliometer calibra tion data for 4 years, using the quartz window . All 

station instruments are maintaining good stable outputs. 

43 
Tabl e 18.--1977 -1 980 field pyrheliometer calibration tests 

Std. ins. Cal. con. Test ins. Ca l con. Response DHf. 

Sta tion Date serial no. (mV mW- 1 cm- 2 ) serial no. (mV mW- 1 cm- 2 ) std./test C%) 

tlLO 11/22 -11/28/77 13909 0.0774 13910 0.0825 1. 0071 -0.71 

13909 0.0774 2119 0.0295 0.9998 0.02 

tlLO 6/30-7/1 1/78 13909 0.0774 13910 0.0825 1. 0097 -0.97 

13909 0.0774 2119 0.0295 1.0079 -0.21 

tlLO 5/16-6 / 1/79 13909 0.0774 13910 0.0825 1. 0056 -0 .56 

LO 1/29-1/31/80 13909 0.0774 13910 0.0825 1. 0016 -0 . 16 

BRW 2/2-2/4/77 13911 0.0856 13913 0.0826 0.9845 1. 55 

BRW 5/2- 5/5/77 13909 0.0774 13913 0.0826 1 .0039 -0 . 39 

BRW 4/26 - 5/9/79 13909 0.0774 13913 0.0826 1. 0038 -0.38 

StiO 1/6- 1/8/77 13909 0.0774 13914 0.0829 1.0110 -1. 10 

StiO 1/5 -1 /6/78 13909 0.0774 13914 0.0829 1 .0 123 -1. 23 

StiO 7/19-8 /9/78 13909 0.0774 13914 0.0829 1 . 0075 -0.75 

SMO 6/2 1-7/2/79 13909 0 . 0774 13914 0.0829 1. 0124 -1. 24 

StiO 1/2 1-1 /22/80 13909 0.0774 13914 0.0829 1.0083 -0.83 

SPO 12/19-1 2/30/78 139 11 0.0856 13912 0.0815 0.9978 0.22 

SPO 12/ 19- 12/30/78 13911 0.0856 2968 0 . 0259 I .0706 -7.06 

SPO 1/ 12- 1/ 13/80 13909 0.0774 13912 0.0815 .9959 0.41 

Calibrating the Schott filters involves the standard instrument with both 

standard and station filter wheels . The standard pyrheliometer holds the two 

filter wheels in alignment. Measurements are taken with each filter through one 

wheel, then two, then reversing the filter wheel order and repeating the procedure. 

Mean output ratios (one filter/two filters) are computed. This develops a correcting factor that is station filter transmission dependent. Table 19 is a compilation of station filter factor data over the same 4-yr period as table 18. Some 

shifting transmission characteristics are seen, the greatest being an approximately 

3% MLO RG-8 filter transmission increase between 1979 and 1980. However, no 

continuous filter transmission degrading, with any filter, is seen at any station. 

Table 19.--1977-1980 field pyrheliometer filter facto r compilation 

Std . ins. Cal. con. 

Station Date serial no. (mV mW-' cm- 2 ) OG-1 RG-2 RG-8 

MLO 11/22-11/28/77 13909 0.0774 1.095 1.093 1.103 

MLO 6/30-7/11/78 13909 0.0774 1.108 1.096 1.107 

MLO 5/16-6/1/79 13909 0.0774 1. 091 1.086 1.109 

MLO 1/29-1/31/80 13909 0.0774 1.092 1.080 1.076 

BRW 2/2-2/4/77 13911 0 . 0856 1.105 1.110 1. 111 

BRW 4/26-5/9/79 13909 0.0774 1.089 1 . 088 1.103 

SMO 1/6-1/8/77 13909 0.0774 1.095 1.105 1.100 

SMO 1/5-1/6/78 13909 0.0774 1.098 1. 103 1. 100 

S~1O 7/19-8/9/78 13909 0.0774 1. 095 1. 100 1.104 

SMO 6/21-7/2/79 13909 0.0774 1.091 1. 098 1. 099 

SMO 1/21-1/22/80 13909 0.0774 1.101 1. 112 1 .099 

SPO 12/19-12/30/78 13911 0.0856 1 . 094 1.098 1.122 

SPO 1/12-1/13/80 13909 0.0774 1.094 1. 098 1.122 

44 
3.B.3 Field Site Activities Summary 

!auna Loa 

Station instruments, trackers, cables, etc., received routine preventive 

maintenance throughout the year. Regular voltage checks at amplifier board test 

points verified their performance. When the amplifiers remained undamaged, 

monthly calibration records revealed steady offset and gain. During January, UV 

radiometer SNI0232 was replaced with UV radiometer SN12350. OG-l and RG-B pyranometer amplifiers, plus diffuse pyranometer and 13-channel radiometer amplifiers, 

be cause of a February lightning strike, were replaced and recalibrated . Diffuse 

pyranometer SN12560 was replaced with diffus e pyranometer SN12502 during April. 

Samoa 

During 19 79 , as specified in the station daily documentation sheets, solar 

radiation instruments received regular maintenance at SMO. Amplifier calibration 

r ecords here show steady offset and gain during the year. A new OG-l pyranometer 

amplifier was installed during April. SMO global pyranometers continue exhi biting 

slow but steady degrading of filter domes, whi ch necessitates more frequent dome 

replacing than the other stations. 

Barrow 

BRW station staff carried out routine program maintenance throughout 1979. 

New OG-l (SN12264) and RG-B (SN12267) pyranometer levels and OG-1 mounting hol es 

were installed and cut during July. Instrument orientation was not changed. The 

filter dome ice crysta l buildup problem continues at BRW. Both instrument ring 

blowers and larger blowers flanking the instruments, which ventilate the filter 

dome exteriors with warmed air, are used. An intercomparison between t he two , 

involving alternating them online and checking nighttime offset voltage differences 

which was begun to determine the different blower e ffects on solar radiation data 

output, proved inconclusive. Both blowers remain online. 

South Pole 

During 1979 SPO winterover personnel carried -out routine i nstrument inspecting and scheduled maintenance, as listed in the daily station documentation 

sheets. The filter dome ice crystal buildup problem occurs at SPO too, although 

it is less intense and dome buildup is not as severe. Light brushing with a 

horsehair artist brush will usually clear the domes, although alcoho l cleani ng is 

sometimes necessary. The very col d , dry polar plateau air inhibits ice crysta l 

adherance. The instrument ring blower system also does a reasonably effective 

clearing job. However, its effect on data output is undetermined. 

3.B.4 Data 

Figures 21 through 2B pre sent 2-min average irradiance plots (kilojoules/ 

square meter) over the true solar day, at the four baseline stations, under t he 

respective area's various representative synoptic conditions . Top to bottom, the 

curves are flat surface extraterrestrial irradiance, quartz, GG-22, OG- l , and RG-B 

pyranometer and UV radiometer (excluding S~!O) irradiance data. Contamina t ed data 

and instrument or ICDAS malfunctions must be segregated from synoptic induced 

radiation intensity variations at the Earth' s surface . Knowing each station's 

general regional synoptics and examining the plots allow the segregating. The 

curve shape is a qualitative identifier of daily synoptic conditions. 

45 
SOLAR IRRADIANCE AT MAUNA LOA DATE 79/ 119 

100 

N 

, 

~ 

~ 

50 

o 6 12 18 

TRUE SOLAR TIME 

Figu re 21.--S01ar irradiance at MLO, 

29 April 1979. Clear sky conditions 

under both upslope and downslope air 

fl ow regimes, for entire day. 

24 

SOLAR IARADIANCE AT MAUNA LOA DATE. 79/1 16 

1SO 

! 

100 

N 

~ ~ 

.. .. 

,-

50 

o t-----'----

o 6 12 18 24 

TRUE SOLAR TIME 

Figure 22.--S01ar irradiance at MLO, 

26 April 1979. Clear morning sky conditions, sporadic orographic cloud 

buildup in afternoon (cumulus and stratocumulus). 

Figures 21 and 22 show HLO data during diverse conditions. Under the downslope airflow influence during the early morning, upper tropospheric air dominates, 

and clear sky conditions prevail both days. On 29 April (see fig. 21), t he upsl ope airflow regime, beginning during midmorning, is relatively dry, and t he 

t rade wind temperature inversion has remained strong. This effectively inhibits 

orographic cloud buildup above HLO. During 26 April (fig. 22), the inversion is 

wea k, and t he midmorning to afternoon upslope flow is more moist; hence orographic 

cloud buildup takes pla ce over the sta tion, and the chaotic irradia nce pa t terns 

ar e observed . 

Figures 23 and 24 present SPO data under differing wind regimes. On December 

10 the s urface winds were from 060 0 at 5 m s-l. This indicates cold downslope 

flow off the polar plateau . Under this regime, clear, very dry conditions occur , 

wi th little or no precipitating ice crystals (see smooth irradiance curves in fig . 

23) . The SPO station complex's solar overpass is between 0700 and 1000 TST. The 

minute data scatter seen at this time could be related to the station's warm air 

plume causing sporadic global radiation refraction or attenuation . However, it is 

mo re likely that the station power plant exhaust plume causes t he scatte r , because 

t he plume rises until it reaches the inversion level, under surface wind control, 

there trailing off in the inversion level wind direction and mixing with ambient 

air. This could cause small scale clear day curve perturbations. Six weeks 

earl ier on October 23 , as depicted in fig. 24, surface winds were off the Weddell 

Sea, from 3400 to 360 0 at 6 to 10 m s-l. This speed causes moderate to heavy 

blowing snow that reaches well above the surface. Further, there is greater 

relative moisture and more ice crystal precipitation. Veiled cirrostratus cloud 

cover predominates . The pyranometer data point scatter and the irregularity of 

the curve reflect all these conditions. Filter dome ice crystal precipitation 

46 
SOLAR IRRADIANCE AT 5 POLE DATE 79/3<1<1 SOLAR IRRADIANCE AT S POLE DATE: 79/296 

150 150 , 

100 100 

N 

" '; 

'" 

50 50 

a a 

a 6 12 ,. 24 a 6 12 ,. 24 

TRU E SOLAR TIME 

Figure 23.--Sol ar irradiance a t sPa, 

10 Decemb er 1979. Clear sky conditions 

for entire day. Isolated sporadic nature of available global radiation in 

midmorning possibly r es ults from warm 

air plume or power plant exhaust plume. 

TRUE SOLAR TI ME 

Figure 24.-- Solar irradiance at SPO, 

23 Oc tober 1979 . 10/10 thin veil of 

cirrostratus plus heavy blowing snow 

and ice crystals in the early morning. 

4/ 10 veil and lightly blowing ice crystals in afternoon. Note quartz and 

GG-22 filter dome IC buildup (1000-2200 

TST) a nd cleaning (2200 TST). 

buildup caused erroneous quartz and GG-22 data between 1000 and 2200 TST. The 

final data set ha s these data edited out before archiving . 

Figure s 25 and 26 s hows SMO data plots during di f ferent synoptic conditions. 

The plot for 11 January s hows very l ittle available global irradi ance reaching the 

surface. Easterly tropical trade wind induced rain and rainshowers with 10/10 

cumulus and s tratus c l oud cover, both caused by orographic moist trade winds air 

lifting against the island's centra l mountains, dominate the synoptic patte rn for 

the day. Data point variability and curve shape in fig. 25 show t hese conditions. 

Figure 26, the 30 January irradiance data plot , accurate ly represents the we athe r 

pattern for the day. Broken orographically induced cumulus, which average 4/ 10 

cover ove r the day , cause the quantitative variance between s mall and l a rge data 

point sca tter throughout the day. 

Figure s 27 a nd 28 present BRW pyranometer data under varying cloud covers. 

During 20 April, a thin veil of cirrostratus with 6/10 average sky cover and 

moderate blowing s now were observed throughout the day. Scatter about clea r day 

curves in fig. 27 depi ct these conditions. Further, April is t he month when the 

Arcti c haze phenomenon occurs a nd various European industrial region pollutants 

are transport e d toward BRW over t he polar region. The se phenomena could cause 

additional data point variability. Note that the variability is comparable to 

that in fi g. 24 , which presents SPO data under similar conditions. Figure 28, 

47 
SOLAR IRRADIANCE AT SAMOA DATE: 79/ 11 

o 6 12 18 

TRUE SOLAR TIME 

Figure 25.--Solar irradiance at SMO, 

11 January 1979. 10/10 cumulus and 

stratus c loud cover for the day with 

rain and rainshowers . 

SOLAR IRRADIANCE AT BARROW DATE: 79/ 110 

150 

100 

50 

2< 

~--~~------------~~~ 

o 6 12 18 

TRUE SOLAR TIME 

Figure 27.--Solar irradiance at BRW, 

20 April 1979. 6/10 thin veil of cirrostratus and moderate blowing snow 

throughout observing day . 

48 

SOLAR IRRADIANCE AT SAMOA DATE: 79/30 

150 

100 

50 

r-----~~------------~----~ 

o 6 12 18 

TRUE SOLAR TIME 

Figure 26.--Solar irradiance at SMO, 

30 J anua ry 1979 . Broken cumulus c loud 

cover averaging 4/10 for the day. 

SOLAR IRRAOIANCE AT BARROW DATE: 79/ 66 

150 

100 

50 

------~ --------~------~ 

o 6 12 18 

TRUE SOLAR TIME 

Figure 28 .--Solar irradiance at BRW, 

7 March 1979 . Clear sky conditions for 

entire day. Note quartz , GG-22, and 

OG-1 filter dome IC buildup (0800-0900 

TST) and cleaning (0900 TST) . 
>. 

o • 

7 0

r 

'_ I I I T , , , { 

5'0 ~ 1980 

3.0 

5.0 ~ 1 1979 

3.0 

7.0

t 5.0 1 1978 

3.0 

::t I'" ~~ ,2', , I:::=:: 1976 

JF M AMJJASO ND 

Figure 29.--Available solar energy at 

SMO in 1976-80 . 

representing 7 March, shows BRW data under clear sky conditions all day. As in 

fig . 24, erroneous pyranometer da ta are seen between 0800 and 0900 TST because of 

precipitation obscured quartz, GG-22, and OG-1 filter domes. Edit routine s be fore 

archiving eliminate these . 

As a part of GMCC's Acquisition and Data Management Group's project to 

convert SMO station power to a solar and wind system, a daily and monthly dependent available global solar energy study was undertaken. Daily total available, 

monthly total available, and average daily available global solar energy data 

(kilowatt-hour/square meter) over a 4~-yr period were prepared for analysis . 

Figure 29 presents measurements of average daily available energy, during any 

given month and year, from January 1976 to August 1980. The expected midyear 

decrease is evident, because austral winter solar elevation is lower. The yearto-year average daily available energy changes during the austral winter months 

are less than the summer month changes, which implies more synoptic variability 

during these warmer, wetter months (September to March) . Fi gure 30, which presents a daily total available global solar energy during 1978, shows the day-today synoptic va ria tion r e flected in available energy changes . Examining the 

overall curve reveals the austral winter decrease previously mentioned and a 

pattern equivalent to the 1979 curve in fig. 30. However, the wide ranging dayto-day variability is caused primarily by the changing weather patterns, specifically cloud cover and precipitation. 

49 
10r---------_,r---------,-----------,---------_,r----------,----------, 

>-

o '" 

c 

Q) 

~ 

8 

4 

(!) 2 

>-

~ OL-______ ~-----L------=_-----L----~~----~------~------L-----~-------L------~-----J ~ J F M A M J 

UJ 

~ 10r-----------_r------------~----------_r------------r_----------_r----------_, 

(5 

U) 

iii 

D 

2 

(!) 

Q) 

:0 

~ 

~ 

<>: 

iii 

(5 

I8 

4 

2 

O~--------~----------~----------~----------~----------~--------~ J A S o N o 

Month 

Figure 30.--Daily variation in available solar energy at SMO in 1979. 

BARROW 

79 

IV 

WI NO SPEED (IUS) 

__ 11'.5<$ 

cmzm$'''S< IO 

D _ 5 ~ 10 s 

WIND ROSE 

WIND rREQ 

• 

E 

50 

Figure 31.-- Windrose for the GMCC 

Ba"rrow observatory for 1979. The distribution of wind direction and windspeed are in units of percent occurrence for the year. Windspeed is shown 

as a function of direction in three 

speed ranges: less than 5 m .-1, 5 to 

less than 10 m s-l , and 10 m .-1 or 

greater. 
3.9 Meteorological Measurements 

3.9.1 Barrow Climatology 

The Barrow GMCC Observatory is located about 9 km southwest of Point Barrow 

on a small rise in the tundra between two saltwater lagoons. A uniform snow cover 

hides these topographic features during 8 months of the year . No other topographic 

barriers exist within a 300-km radius of the observatory; thus the surface winds 

are mostly determined by large scale pressure systems. Between stormy periods, 

whe n most westerly winds occur, the surface winds are easterly, resulting from the 

outflow from the polar anticyc l one. The radiation climate at BRW is strongly 

influenced by the stratus cloud layer that forms in the l a te spring and persists 

throughout the summer. The stratus layer denotes the top of the boundary layer 

cooled from below by the Arctic Ocean and warmed on top by subsiding air aloft. 

Onset of the stratus in the spring is closely tied to the appearance of leads 

(ice-free regions) along the coast. 

The distribution of hourly average resultant windspeed as a function of the 

res ultant wi nd direction is pre sented in fig. 31. As in 1978 and previous years, 

easterly winds are dominant, occurring about 64% of the time. The largest percentage of stronger winds also occurs in this sector; 81% of the winds greater or 

equal to 10 m s-l are in this sector. At the othe r extreme, calm winds (less than 

0.5 m S-l ) occur 0.6% of the time. Table 20 lists a breakdown of the meteorologica l mea s urements by month. Northeasterly through easterly winds are predominant 

in all months except Decemb er when winds from a westerly direction are most common. 

Table 20. --1979 Barrow ObservaLory monthly cl imale summa ry 

J" re b la r Apr Ia y Jun Ju l Aug Sep Oc t Nov Dec 

Prevailing .... ind ENE ESE ENE ENE ENE E ESE r. E NE NE W 

di recLions 

Average .... 'l nd 5 8 4 . 3 6 . 0 6.9 5.3 4 9 4.3 5 5 4.9 7 . 9 7.0 5 6 

speed (m , ' ) 

~Iaxinlum wind 14 II 12 18 IJ 12 9 12 II 16 18 19 

speed'-' (m s - I) 

Di rection o f max . 201 257 94 250 11 3 250 258 264 119 82 89 269 

\o'ind'" (deg.) 

Average station 1012 4 1027 5 1024 9 1018.4 1014 2 1012 0 1009 8 1007.5 IOiO 4 1009 .4 1001.3 1010 2 

pressure (mb ) 

Maximum pressure"~' 1035 1044 1036 1040 1023 102 1 1017 10 18 1028 1022 102 i 1041 

(mb) 

~Ii n imurn pressure'~' 977 1004 1009 989 1002 994 996 995 990 992 qn 973 

(mb) 

Average air - 18. -29.4 -27 6 -1 8. 3 - 6.4 0.1 4.8 6.0 1. 1 -8. 2 - 13.1 - 25. 

temperature (Oe) 

~Iaximllm temperature* - 6 -14 -8 5 12 15 18 8 0 0 -5 

(0e) 

~Iinimum temperature·:' - 36 -43 - 40 - 34 -18 -5 - 2 0 -6 -1 9 - 26 - 38 

(0e) 

"~Iaximum and minimum values are hourl y averages. 

51 
MAUNA LOA 

79 

w 

WINO SPEED (W/ S) 

__ ~s.s ~ 

~~'.5 O 

D WSl to 

N 

s 

WIND ROSE 

WIND rRE:Q 

• 

E 

Table 21.--1979 tlauna Lo. Observatory monthly c limat.e 

Jan Feb H" Apr 

Prevailing wind WSW WSW SSW SSW 

direc tions 

Average wlnd 5.2 4.' 4.7 5.' 

speed (m , ' ) 

Maximum .... ind 12 14 IS 14 - speed1.- (m , ') 

Direction o f max. 257 188 1'1 207 

wind* (deg.) 

Average station 679.0 678.7 679.5 679.2 

pressure (mb) 

Maximum pressure1, 683 682 682 684 

(mb) 

Ninimum pressure'''' 675 673 673 674 

(mb) 

Average air 2.4 2.6 4.8 6.1 

temperature COe) 

Maximum temperature* 13 II 17 14 

(0e) 

Minimum temperature* -4 -3 -2 0 

(0e) 

-:'Maximum and minimum values "e hourly averages. 

Figure 32.--Windrose for the Mauna Loa 

Observatory for 1979 . See legend for 

fig. 31. 

summa ry 

H.y Jun Jul AU8 Sep Oct Nov npc 

NW SSE SE SE SE SE SE SW 

3.' 3.5 4 . 3 4.3 3.5 4.0 4.6 4.4 

10 10 13 IS • " 14 13 

138 146 13. 11 6 86 138 138 141 

681.4 68 1.8 682.5 682.2 681.9 682.2 680.5 681.0 

685 685 686 685 684 685 684 685 

677 67' 678 67. 679 67. 67. 674 

8.0 8.2 8.6 8.6 8.4 7. I 6.3 6.8 

16 15 IS 18 16 15 16 16 

0 2 2 2 2 0 0 

52 
The month-to-month changes in temperature and wind indicate the extent of the 

winter at Barrow. Winds are stronger during winter, and the temperatures follow 

an orderly progression except during January. In 1979 the minimum hourly average 

temperature was 43°C. The average temperature for the year was -11. 3°C . NWS in 

Barrow village reported an average value of -lO.6°C. The average pressure for the 

year was 1013.5 mb, 2.7 mb below the value reported by NWS. The average windspeed 

was 5.7 m s-1; NWS reported 5 . 3 m s-1 

3.9.2 tlauna Loa Clima tology 

Throughout most of the year the meteorological situation at tlLO is controlled 

by the diurnal heating and cooling of the surface of the mountain. At the level 

of the observatory (3.4 km) the nocturnal downslope condition lasts about 12 to 13 

hours a day, and the upslope flow lasts about 8 hours each day. In the intervening transition periods the winds are light and variable. The windrose (fig. 32) 

shows the general prevalence of downslope conditions with winds from the SQuthsoutheast and southwest. Higher windspeeds (~10 m s- 1) occur most commonly (80% 

of the time) with stormy periods and come from these southerl¥ directions. The 

upslope or northerly winds are predominately less than 10 m s 1. Calm conditions 

(windspeeds <0.5 m s-1) occurred less than 2.2% of the time i n 1979. The maximum 

average resultant windspeed reported for the year was 15 m S-1. 

Month-lo-month variations in the important meteorological parameters are 

listed in table 21. Westerly winds are the most prevalent throughout the winter 

and spring months (December through April). Southeasterly winds are most prevalent between J une and November. The average monthly station pressure changes very 

little, less than 3.5 mb. The average for the year was 680.8 mb. The average 

monthly temperatures vary over. a range of 4.2°C with the annual average at 6.SoC. 

3 . 9.3 South Pole Climatology 

The persistent s urfa ce wind from a grid northeasterly direction is the 

overriding climatological feature at SPO. It is an inversion wind from approximately 50° to the right of the Antarctic Dome. SPO is located on the AmendsenScott plateau (elev. 2.85 km), which has little topographic relief within a 100-km 

radius of the station. The plateau is a slight depression near the western edge 

of the main ridge of eastern Antarctica. The highe st point (elev. 4 km) on the 

plateau is about 900 km east-northeast of the Pole. 

In fig. 33 the distribution of windspeed is presented in polar coordinates as 

a function of wind direction. The most prevalent wind direction is from the eastnortheast, which is at variance with the preceeding 3 years when northnorthe asterly winds dominated. During 85% of the hours in the year, the wind 

blows from the northeasterly quadrant. The winds associated with storms are from 

the north, but windspeeds equal to or greater than 10 m s-1 occur during only 1% 

of the hours. The maximum hourly-average windspeed observed during the year was 

only 12 m s -1. Calm conditions were reported for only 3 hours in 1979. The G~ICC 

anemometer is mounted at a height of about 10 m and positioned about 30 m grid 

north of the CAY. 

Table 22 lists monthly average tempera tures, which s how the extent of austral 

winter on the Antarctic plateau. The average temperature remains below -SOoC for 

8 months of the year. The annual average temperature for 1979 was -48.9°C, only 

0.5°C colder than 1978. The maximum hourly average temperature was -18°C, and the 

minimum was -77°C. 

53 
SOUTH POLE 

79 

w 

WIND SPt:ZD (VI S) 

-- .:\,"<;& 

mmzi!!i'.S < 1O 

o WSOllO 

Tabl e 22.--1979 

Prevailing wind 

directions 

Ave rage wind 

speed (m , ' ) 

Maximum wind 

speed* (m 5 -1 ) 

South 

Direction o f max. 

wind* (deg.) 

Average station 

pressure (mb) 

Maximum pr ess ure* 

(mb) 

Minimum pre ssure* 

(mb) 

Average air 

temperature (Oe) 

Haximum temperature* 

(oC ) 

Minimum temperature* 

(Oe) 

N 

• 

• 

s 

Pole Observatory 

J.n Fe" 

ENE E 

4.5 4.7 

9 10 

340 1I0 

685.8 681. I 

693 692 

676 670 

-25.7 - 4 1 .4 

·18 · 29 

-35 - 52 

*MaximulIl and minimum values He hourly 

WIND ROSE 

E 

.. 111) .... 

• 

monthl y c1 imate 

Ndt" Ap' 

NE NE 

5.5 5.9 

1I 10 

360 ala 

676. I 681 . I 

688 696 

666 666 

-S 1 .2 -53 . 5 

- 35 - 38 

- 65 -66 

averages. 

Figure 33.--Windrose for the South Pole 

Observatory for 1979. See legend for 

fig . 31. 

s ummary 

H.y Jun Jul AU8 Scp Oct Nov Dec 

ENE E ENE NNE N NE N NNE 

4.9 5.2 4.9 6.1 6.4 5.6 5.4 4.2 

8 1I 9 10 12 9 1I 9 

040 360 100 020 320 020 020 020 

670.4 676.1 662.1 67 1. 4 674.7 ,672.2 682.4 687.0 

683 684 672 691 693 691 696 700 

659 666 647 659 657 662 668 676 

-62.0 -57.2 -63.9 -61.6 - 56.0 -52.2 - 36.4 - 26. I 

-43 -46 -45 -47 - 38 -36 -27 -18 

-73 -69 -77 -72 - 69 -64 -48 -32 

54 
SAMOA 

79 

w 

WIND SPEED (W/ S) 

'' 5< ~ 

emma S<lO 

D .. 51 10 

SAMOA 

79 

w 

WIND SPEED (III/ S) 

_ li' W!I < $ 

mz!2Za $ , . S < 10 

D .5110 

N 

s 

N 

s 

3.9.4 Samoa Climatology 

WIND ROSE: 

E 

WI ND f'REQ. 

X 

WI ND ROSE 

E 

WIND rRO:I. 

X 

SAMOA 

79 

w 

W. NO SPEED (II/ S) 

- !l$ .'< $ 

c::?iZl3$"5 < IO 

o n liO 

N 

s 

WI ND ROSE 

E 

WIND FlU)Q. 

X 

Figure 34.--Windrose for the Samoa Observatory for 1979. See legend for 

fig. 31. 

The SMO anemometer and thermometer were located on the sampling tower atop 

Lauagae Ridge during 1979 . The anemometer was 14 m above ground near the sampling 

stack intake, and the thermometers were at 4-m height. Figure 34 shows the distribution of the resultant windspeed, in three classes, as a function of the 

resultant wind direction, in 16 classes. The trade winds at Cape Matatula are 

depicted, with the occurrence of directions in the southeastern quadrant occurring 

71% of the time . During the year, winds from the northwesterly direction occur 

14% of the time, with the northeasterly and southwesterly quadrants contributing 

the remaining 15%. When the summer months (December-March) are considered separately, a significant change in the distribution occurs. 

55 
Table 23. --1 979 Samoa Obs ervatory monthly cl imate summary 

Jan Feb tla r Ap' H,y J" n J"I A", Sep Oct Nov Dec 

Preva i 1 ing Idnd SSE SE SE SSE SE SE SSE SE SE SE SE SSE 

direc ti ons 

Average wind 3.7 5. I 3 .7 2.5 4.4 5.8 5.2 4. 2 5.7 5.3 4 . 3 3 . 7 

s peed (m , 'J 

tlaximum wind 10 10 8 7 9 13 l2 8 10 II 9 13 

speed':' (m 5 - 1) 

Direction of max. 290 141 149 139 140 110 lSI 11 0 152 117 165 320 

I.'ind'·' (deg .) 

Average station 997. 1 1000. 2 999 9 1000 6 1000 9 IDOl .5 1002 ., 1002 2 1001 .8 1000. 999 .9 998 .4 

pressure (mb) 

tlaximum pressure'-' 1002 1004 1003 1004 1007 1005 1007 1005 1007 1005 1004 1004 

( mb ) 

inimum pressure'" 991 99' 996 996 996 996 995 996 99' 99' ~9 3 992 

(mb) 

Average ai r 28 . 6 28 3 28. 7 28 6 28 4 28.2 27.3 27. I 27 .3 27 , 27 . 8 27 .9 

temperature (OC) 

tlax imum tempera lur e"" 34 31 32 32 3 1 32 31 32 30 30 3 1 32 

(OC) 

Iinimum temperalur e'··· 24 22 23 24 24 24 24 21 23 23 23 23 

(OC) 

"'~Iaximum and minimum values , .. hourly averages. 

Figure 34 shows the windroses for 1979 with December, January, February, and 

March winds. Clearly the percentage of wind directions in the northeasterly guadrant are affected most. Seventy-four percent of all winds greater than 5 m s 1 

from the northwesterly directions (N, NNW, NW, WNW) occur during the summer . 

During the remainder of the year, windflow is strongly dominated (72% of the time) 

by the southeasterly trade winds. Stronger winds occur during a larger percentage 

of the time in those directions as well. 

As shown in table 23, seasonal variations of all other parameters are small. 

There is only a small indication of stronger winds and cooler temperatures in 

winter than summer. The average temperature for 1979 was 28°C, compared with a 

27°C measurement at the airport in Tafuna. The average windspeed was 4.5 m S-l 

compared with 5.2 m s-l at Tafuna, and the average station pressures was 1,000.5 

~b, compared with 1,010.6 mb measured by NWS. The height difference between the 

GMCC observatory and the airport station is about 78 m, which accounts for 8.9 mb 

of the 10.1 mb difference. 

3 .10 Precipitation Chemistry 

The precipitation chemistry program continued with little change during 1979 . 

Precipitation samples were collected at. the 4 baseline observatories, 10 regional 

sites, and 6 Washington, D.C., locations. Monthly samples were sent from the 

regional and baseline sites to EPA laboratories for chemical analysis. Spe c ial 

studies were continued at MLO, using the ion chromatograph. 

56 
4L-~_L-L- 1 __ L- L-~ ~~~~ 

JFMAMJJASOND 

Figure 35.--Monthly precipitation 

weighted means for five sites on the 

Island of Hawaii during 1979. 

3.10.1 Baseline Measurements 

Figure 36.--Comparison of monthly precipitation weighted pH value s for Hawaii 

and Kauai during 1979. 

The five-site special network on the Island of Hawaii continued on a dailybiweekly schedule; for details on locations, see previous GMCC Summary Reports. 

The monthly weighted pH values are plotted in fig. 35. The steady increase in 

acidity with elevation is still evident in the 1979 data as it was in previous 

years . Concern about the volcano as a source of the acidity prompted establishment of a site on the island of Kauai. Figure 36 shows the weighted average 

monthly values of pH with those of Hilo. The two sites are the most comparable in 

relation to elevation and orientation into the trade winds and show no significant 

difference in acidity levels. 

57 
H+ = 89 

1976 

AWV 

1976 

>---; 

H+ = 81 

1977 

AWV 

1977 1978 1979 

Figure 37.--Monthly precipitation weighted hydrogen ion concentration for t he 

Washington, D.C., area. 

3.10.2 Regional Measurements 

The 10 WHO regional sites continued to be reevaluated during 1979 in expectation that they would become part of the National Atmospheric Deposition Program in 

1980 . At that time, precipitation would be sampl ed weekly instead of monthly. 

3. 10.3 Washington, D. C. , Network 

The data for the Washington network are shown in fig. 37 . 

3.1 1 Meteorological Traj ectories 

GMCC personnel use such meteorological data as back air trajectories calculated from the Heffter/ARL model to interpret data at baseline sites . At BRW, 5-

day back trajectories (300 to 2,000 m) have been drawn from February 1975 to January 

1980. At MLO, 10-day ba ck traje c tories ( 300 to 5,000 m) have been calculated for 

the same period. These se ries of back trajectories for both stations are available 

from mlcc on microfilm . 

Figure 38 shows back trajectories to MLO for a given day. A, B, C, and D 

refer to 0000, 0600, 1200, and 1800 CUT, the times when these traje c torie s passed 

over MLO. To summarize the 5-yr data period by using trajectories, a climatology 

was constructed using a classification system shown in fig. 39. Trajec t ory 

directions were divided into six classifications. Four types, NE, SE, SW, and NW, 

are trajectories whose paths are in the four quadrant s, 0°-90°, 90°-180° , 180°-

270°, 270°-360°, respectively . A special case (NW/E) was created because a large 

number of traj.ectories crossed the 0° line, influenced first by the westerlies and 

t hen by the easterlies. Figure 40 summarizes all trajectory classifi ca tions for 

the 5-yr period . The seasonal nature of the flow to MLO is shown by the peaks of 

easterly flow in s umme r and westerl y flow in winter . 

58 
Figure 38 . --Examp le of a 10-day bac k traj ectory to MLO. 

NW/ E (22%) 

o· 

NW (21 %) NE (16%) 

270·--- -*"-----+---- --+--90· 1000 km 2000 km 

SW (15%) SE (22%) Type 0 (4%) 

180· 

Figure 39.--Trajectory types us ed in classifying traj ectories from February 1975 

t o January 1980 to MLO. Percentage ove r the total period is given in parentheses. 

59 
250 

200 

150 

100 

50 

0 

200 

150 

100 

50 

0 

~ 

~ 200 ~ 

~ 

U 150 

0 100 ~ D 50 E 

~ 

z 0 

250 

200 

150 

100 

50 

0 

200 

150 

100 

50 

0 

J F M A M J 

SE 

NE 

NW E 

NW 

SW 

J A SON D 

Figure 40 . - -Summary of the number of 

cases of a given trajec t ory for t he 

5-yr period on a monthly basis. 

3. 12 Data Management 

3.12.1 Data Acquisition 

Hardware 

The Acquisition and Data Management Group oversees the Instrumentation 

Control and Data Acquisition System (ICDAS) . During the past 3 years the overall 

performance of the system has improved to only 5% nonoperational in 1979 (see fig. 

41) . For all stations combined the ICDAS was down an average of only 18 days . 

The BRW system functioned well for 94% of the time in 1979; this record is 

consistent with that for previous years.. Most downtime at BRW resulted from a 

multiplexor-digitizer problem and tape drive alignment difficulties. The ICDAS at 

MLO operated for 89% of the time in 1978, which matched its 1978 performance. 

Most downtime at MLO occurred during the second half of the year when the station's 

60 
system had power problems, a misadjusted memory voltage, and tape drive problems. 

The performance of the SMO ICDAS improved over that for 1978 to only 3% downtime 

in 1979, mainly caused by power problems, although the tape drive caus ed some data 

loss. The SPO ICDAS had a remarkable year with less than 24 hours of downtime. 

In 1979 more data were lost because of tape drive problems than for any other 

reason . Sometimes these problems resulted because the tape drives were misaligned. 

Toward the end of the year the drives at BRW, SMO, and MLO were all experiencing 

an occasional mysterious rewind or backspace to the beginning of tape. During 

1980 we will clarify and standardize the maintenance procedures for the tape drive 

to minimi ze data lost from tape drive problems. 

Hardware modification to the ICDAS, designed to reduce system noise, proceeded 

during the year. The NOVA minicomputer's switching power supply , which could 

generate RF noise as well as an audible high frequency, was replaced with a quieter, 

linear power s upply. Another modification was replacement of the NOVA's front 

panel incandescent light bulbs with light-emitting diodes. The LED's require less 

power and have the added benefit of hardly ever burning out. 

These modifications were made to the MLO and BRW computers in April . SMO's 

upgrading occurred in December after a delay for further testing. Although the 

front panel on the SPO's NOVA has been modified, the power supply will not be 

changed until the station opens in November 1980. In addition to the station 

computers, the spare NOVA and the NOVA in the reduction lab have been upgraded. 

Another hardware project comp leted in 1979 was the design , buildi ng , and 

che ckout of controllers for CO 2 tank and flask analysis. This work was done in 

cooperation with the GMCC ~lonitoring Trace Gases Group. The "brains" of each 

controller is a 2-80 microprocessor that we programmed to accept information from 

an operator, switch solenoids, collect data, and perform other functions of tank 

and flask analysis. The results are sent to an HP desktop computer for final 

processing and output. The tank controller was installed in March and the flask 

ICDAS OPERATIONS· 1977, 1978, 1979 

100--------------------------

75 --------------------------

50-----r----~-------------

25 --~~-------------------

777879 777879777879 77 7879 

o -s-o-u-t-h....:....-s-a-m-o-a----:-M~a-u-n-a--B-a-rr-o-wPole Loa 

61 

Figure 41.--ICDAS opera t ions for 1977, 

1978, and 1979. For each year the percentage of operation time is s hown. 
Table 24 .--Inventory of GMCC data tapes at ~o rld Data Center-A 

Tape Da te 0 f Period 

No. name issue Parameter Sta tions of da ta 

I flLONFl 12/9/77 Volumetric light sca tte ri ng M10 1974-1976 

2 GP0101 1/16/78 Co nde nsation nu cle i BRW 1975, 1976 

GPOL~I co ncentration flLO 1975, 1976 

SPO 1975 , 1976 

3 A78~ 76 3/17/78 Solar i rrad ianc e flLO 19 77 

4 A78083 3/24/78 Solar i rradiance SflO 19 77 

5 A78100 4/10/78 Solar irradia nce BRW 1977 

6 A78104 4/14/78 Solar i rradia nce fl10 1976 

7 A78 132 5/ 12/78 NIP radia tion BRW, flLO 19 77 

SfIO, SPO 

8 A78 139 5/19/78 Wind, pressure, BRW, fl10 1977 

temp. , hum idity SMO, SPO 

9 A78146 5/26/78 Solar irradiance SflO 1976 

10 A78160 6/9/78 Solar irradiance SPO 1976, 19 77 

11 A78230 8/18/78 Solar i rradiance BRW 1976 

12 A782 72 9/29/78 Solar i rradia nc e BRW, flLO First ha lf 

1978 

13 A78279 10/6/78 Solar irradia nce Sfl0 First half 

1978 

14 A7912 7 5/7 /79 Solar irra diance SflO 1976 

(research- cooperator format) 

15 A791 28 5/7 /79 Solar irradiance SMO 1977 

(research- cooperator f ormat) 

16 A79208 7/27/79 So l ar irradiance M10 Second ha lf 

1978 

17 A79222 8/10/79 Solar i rradiance SMO Second half 

1978 

18 A80010 1/25/80 Carbon dioxide flLO 1974-1978 

19 ABOOll 1/25/80 Ca rbon dioxide SPO 1976 

20 A80012 1/25/80 Carbon dioxide BRW 1973-1978 

controller in August. The Acquisition and Data Nanagement Group' s part i n the 

project wa s documented in a paper pre sented at the WHO technical conferenc e in 

Boulder this August (Harris et al., 1980) . 

A p rototype controller for CO 2 field operations has bee n built, and wo rk is 

b eing done on the software to support it. We are also eva luating a Deck Tape II 

cartridge system, which if viable, wi ll all ow the controll ers to become stand 

alone, data logging syst ems. 

3. 12.2 Archiving 

Table 24 lists the GflCC data archived at the World Data Center-A in Asheville, 

North Carolina . Each file on the archive tapes is preceded by a description of 

the data in alpha numeric form. Cop ies of these tapes can be obtained from the 

Computer Products Branch, National Climatic Center, Asheville, NC 28801, FTS 672-

0203 or (704) 258-2850 ex t. 203. GNCC archived data tapes are located i n tape 

deck no . 9708 . 

62 
3.12.3 Processing 

A new data set combines important GMCC measurements with information about 

variability, instrument performance, and evidence of local pollution. The form of 

the data set, consistent with guidelines set down in WHO 299, has a line for each 

hour of the station year. The data on each line are described in table 25. 

Figure 42 shows sample output from a program written this year to utilize 

this new data set. The plot labeled windrose shows the wind distribution according 

to 16 22.5 0 wind direction intervals and 3 windspeed intervals. Carbon dioxide 

and condensation nuclei measurements were also averaged within the 16 wind direction intervals and plotted on the graph labeled climatology. The table below the 

graphs presents the same data in tabular form with the addition of CO 2 and CN 

standard deviations based on minute data . 

BARROW 

76 

w 

1"1'11) SPttlI (II/S) 

_ !>I"<S 

IZ:ZZI ~ , ., < 10 

o -SIlO 

DAT" rCA BARRCJI..I 

DOR CO<! 

N 

.. s 

V[o\R 1976 

CO<SQ cO<! '" 

WIND ROSE: 

.1 1'10 J'REQ 

, 

E 

BARROW 

'6 

W 

¢ 

"" '" 

CLIMATOLOGICAL 5U"'tV.RY 

'" so CN CALM 

;f> 

""'" "p,,, !TALLYI ICH-]I ( TAlLYI ['AlLYl 

N 335.7 1.231 ' ,go; .09 .2"53' >« " 336 . 6 ... . 3<. ,,. .238" m 

'" 335.8 .2'00 ' -., '21 .115 .36 C'" ]3"5 ." . .,... "'. 10. .'66 '6' C 333.'+ I.o?l" · ,0>, 13' · 190' ,... , CS[ 333 .8 ..... s· ,,, 276 .2"50 ' '" , S[ 335.2 .913' lB. '6' .'+06' '21 , SS[ 333.8 .1 93: '59 '" .<!So-

"' 3 

S 333.9 .198 ' ". 26' .... '63 SSW 33'<.8 .3'+ 1' 310 • "'" .'67 '" sw 336." .170 ' , .. m .i?22 • '" 3 

"'" 336." .5'+2 ' 599 3D" · 1'+6 52' • 

" 335 .7 .993· 62' 276 · "" '26 • """ 335 .0 I. 338 · m ~~ .333 219 , "" 336.2 . S»' ..., ., ... '27 • """ ll!!.O .197 ' 13' .... .305 56 • AVG/ TOT 335.1 .'101 ' 6'''' ." .... 6 ,,.. " EACH OIR£CTI~ SIN CONTA INS '- 11.25 D£CRE(S rR()1 It()lCUEO OIR£CTICtl. 

VAll£S R£~TEO rclR CN AR£ OCOt£TR1C 1'£.t.N ,t.J{) LOGAA1T~lC STAt()ARO D£V1U1ON. 

F'IELOS w-tI CH J,R£ F' ILL(O WITH NII'£S D£NOTE H1SSIN:i OU .... 

STAt()ARO D£vI ATID'6 .t.R£ D£RIVEO HICJ1 (1.£ HINJT( AV(RAG( V.I.lt.l:S. 

A STAR C' ) 1t()I C"'TES THAT CN:-I1INJTE DATA I.£R£ AVAILAa.( 

r~ LESS THAN 75l ($ TI< H1RS wiTHIN THIS SIN . 

N 

.... 4' 

.... 

s 

WIN:) SPEED (I'£t(RS ptR S£CCN:)I 

.'5(010.'5<'5 'j<oWS<]O 16)010 

1 T"-lL YI ITA.LL YI 1 TAlL YI 

'" " • '" ", • ." ". " '" ,.. "'3 

'9' 69' ,,, '66 3>, 2D 

'22 '07 • "' .. , "6 "6 • "6 '66 '6' m " 59 

'69 '" '02 

3<6 ". m 'S"< " 29 

'79 '02 52 1<, " .. "'''' "'133 '''' 

SU< 

CI.IIdATOLOG o ."eN 0:: C02 

E 

NUCLEI 

~, 

DIST 

(TAlL YI lPCTI 

26Z ,., "6 '.9 ;0;' 6. , '26' ''t.'!> 

'''06 16.1 

... 6.' 

23' '.6 .06 .. , 

'DO ,., m 

,,. '-' 

5.' 

'3'0 6.' 

.... 9.' , .. ... m ' .6 

'92 U 

S"19 100.0 

Figure 42.--Sample output from program using new data set from GMCC Barrow station 

for 1976. Left: windrose. Right: distribution of aerosol and carbon dioxide 

concentrations as a function of wind direction. Bottom: climatological summary. 

63 
Table 25. --0escrip lions of da t a for ea c h line o f new data set 

field 

n o. Parameter format 

I ISTA IX, I3 

2 !DATE IX, IS 

3 IHR IX, 12 

4 CO2 IX, r6. I 

5 C02 SO IX, r 6 .3 

6 ITAL IX, I3 

7 I GE IX, I S 

8 GESD IX , f6. 3 

• JTAL IX, I3 

10 NEPHI IX, 1 7 

II NEPH 2 17 

12 NEPII 3 17 

13 ~'EPII4 17 

14 IRWD 2X, I3 

15 RWS 2X, F4. I 

16 PRESS I X, f7. I 

17 AIRT IX, f 6.1 

18 DEW IX, F6.1 

" IFLG 2X, A2 

20 IPLFLG IX, AI 

21 IeOFLG 2X, A2 

22 I C02FL 2X, A2 

23 IGEFL 2X, A2, 2X 

*Origi na l Bsp ha ve been multiplied by 

Comment 

BRW = 199, tlLO = 31, ~I O 191, SPO III 

HOOD, GMT , Jul i an datf' 

Ho ur begi lllllng (0- 23) , GMT 

CO, avera ge in 1959 SIO index 

Ho urly sl.andard of CO2 based on mi nute data 

Tally of minutes in hou r for CO2 

Geome tri c mean co nde nsa t ion nuclei concen t ra ti on (cm 3) 

Loga rithmi c s tanda rd dev ia t i o n fo, the hour based on minute data (cm- 3 ) 

Tally of minute s in hou r [or CN 

Geometric mea n o f vol umetric 1 i ght sca ttering (m- I ,,: 10- 9 ).;: , 450 nm 

Same os above, 550 nm 

Same as above, 700 run 

Same os above, 850 nm 

Res ultant wind direction i n deg r ees 

Res ultant wind speed (m s - I ) 

Atmosphe ri c pressure (mb) 

Air temp e rature (OC) 

Dew point tempe ra tu re (OC) 

Waterman CO, flag s: 

Codes identifying data s uspect.ed as no t being representa t ive of backg r o und cond i tions: 

AC Airline cont.aminated 

GA Ground air - intake unintentionally near ground l eve l 

Le Lo cal contam ination (e.g. , au t omobile traffic at obse rvatory ) 

RV Slripchart recorder trouble ca u si ng variability 

SI Suspect instrument - data are no t markedly different from s urrvu nding hours , s pecific instrumental prob l em has been identified 

ST Suspect time (possibility data are logged at ""rong ho urs of day) 

SW Suspect high winds (causing pressure reversal in air intake) 

V Stripchart trace variable 

VA Variability caused by wind fl ow from Aunuu Isla nd (SMO) (Wi nd directio n ap prox. 150 t.o 180 degs.) 

VO Variabilit.y ca used by vo lcanic activity (tILO) 

VV Variabilit.y probably ca u sed by vegetation (SMO) 

VW Variability ca used by wi nd direction (tIET data indicate co ntaminai on coming from known source of pollution) 

Codes giving the reason for missing data: 

AI. Air pump l ea k 

C We e kl y ca libralion 

I Instrume nt (a nd i n s trume nt r elated problems) 

HA Moving analyzer lO ne ... · location 

PF Power fa ilure (unintentional) 

PO Power o utage (intent.ional) 

R Stripchart. recorder trouble (no comput. er l ogged r ecord) 

T Water vapor trap-relaled problems 

TF Wat e r vapor lra p frozen 

U Unkn own (unab l e to assign specific ca u se for missing data) 

Othe r codes - dat a probably OK, but some supporting i nformati on missi ng: 

NC No s lripc harl record ava ilable (computer logged data OK) 

NT Water vapor lrap not i n use 

RC Re fe rence gas con se rv ed (ca 1 ib rat i o n frequen cy reduced) 

p, Evidence of loca 1 pollut.ion from CN record , n d obse rver comme nt.s 

NI: No ICOAS data available 

eF: CO, fill dala used (don' t compute SO from ICDAS) 

GF: CN fi 11 data used (don't compule SO from lC DAS) 

109 . 

64 
4. SPECIAL PROJECTS 

4.1 Comprehensive Theoretical Examination of the Optical 

Effects of Aerosols on the Umkehr Measurement 

The present investigation is concerned with error on the Umkehr measurement 

resulting from a variety of aerosol size distributions, refractive indices , and 

vertical profiles of aerosol concentrations including augmentation in the stratosphere originating from volcanic and possibly anthropogenic sources. All orders 

of scattering are included in the theoretical calculations . Several different 

ozone profiles are used to simulate low, middle, and high latitude conditions. 

Some preliminary results of this investigation are given here. 

The technique used to calculate the haze errors on the Umkehr measurement is 

a modified version of the one used by Dave (1978) for ca lculating the aerosol 

errors on total ozone estimated from satellite ultraviolet measurements of the 

backscattered radiance. The aerosol error on the Umkehr measurement is found by 

taking the difference between simulated Umkehr measurements calculated for modeled 

atmosphere s with and without aerosols. 

The method used to deduce ozone profiles from Umkehr measurements is essentially the one developed by Mateer and Dutsch (1964), which is now the standard 

evaluation system used by the World Ozone Data Center, Toronto. The haz e error on 

the deduced ozone profil e is found by taking the difference between ozone profiles, 

which were deduced from simulated Umkehr measurements calculated with and without 

aerosol effects, respectively. 

4.1.1 Haze Error On the Umkehr Ozone Profile 

Umkehr measurements simulated for atmospheres with and without aerosols and 

for a variety of ozone profiles were evaluated by the standard Umkehr eva luation 

system (Mateer and Dutsch, 1964). A difference Xi(H) is defined by the equation 

t::.X.(H) 

111 

= X.(H) - X., 

(H) where X. and X. are the ozone amounts in the i-th layer deduced from simulated 

eas ur e~ents for ~odels with and without aerosol, respective l y. 

In fig. 43 we show plots of Umkehr layer number vs. percent haze error E to 

the ozone profile s where 

E(%) = 100 t::.X. (H)/x. 

1 1 

Layer 1 has mid layer atmospheric pressure of 500 mb whereas layers 2 to 9 have 

midlayer pressures of 117, 88, 44, 22, II, 5.5, 2.8, and 1.4 mb, respectively. 

In figs. 43-45, T stands for tropospheric aerosols, S for stratospheric 

aerosols, and ST for both combined. Haze models are take n from Dave (1978) and 

ozone and aerosol profiles are taken from Dave (1979). Figure 44 shows the 

effect of changing tropospheric ozone profiles, and fig. 45 shows the effect of 

changing aerosol profiles. 

65 
- - - Model 500·1 

-- Model 500·2 

9 ST S T 

B 

1: 

E 

~ 6 

• 

~ 5 ~ 

.. ! 4 

E 

::> 3 

2 

1 

- 30 - 20 - 10 0 10 20 !30 - 20 - 10 0 10 20 130 - 20 - 10 0 10 20 30 

_ - - Model 300·, 

- - Model 3(XJ.2 

9 ST S T , , 

B 

• \ 

1: \ 

E \ , 6 z 

· > 5 ~ • 

.. ! 4 

E 

::> 3 ( 

2 

1 

- 30 - 20 - 10 0 10 20 !30 -20 - 10 0 10 20 1 30 -20 - 10 0 10 20 30 

- - - Model 400·1 

- _ Model 400·2 

9 ST S T , 

B 

\ 

1: \ 

E \ 

ii 6 \ 

I 

· ~ 5 ~ 

.£ 4 ~ 

E 

::> 3 \ 

\ 

2 

1 

- 30 - 20 -10 0 10 20 130 - 20 - 10 0 10 20 1 30 - 20 - 10 0 10 20 30 

% Error 

Figure 43.--Haze error caused by ozone profiles. Ae r osol profile and opti cal 

properties are held fixed: Haze H, stratosphere ; Ha ze L, troposphere ; aerosol 

r efractive index is 1.5 to 0 . 0i. Aerosol profiles 1 and 3 ar e used. Models 

500-1 and 500- 2 are two different ozone profile s having a t ot a l ozone of 500 

m-atm- Cffi. 

66 
- - - Model 300·2 

--Model 300·202 

9 ST T 

\ 

\ , B \ 

, 7 , ~ , E , , 6 z 

• 

~ 5 J 

~ • 4 ~ 

E 

=> 3 

I 

2 \ , , , I 

- 30 -20 - 10 0 10 20 ± 30 - 20 - 10 0 10 20 30 

- - - Model 400· \ 

--Model 400·1 02 

9 ST T , 

, B 

• , ~ , E 

, 6 1 z 

· ~ 5 Figure 44.--Effect of changing tropospheric aerosol profile. Aerosol optical properties are defined as Haze H, 

stratosphere; Haze L, troposphere; refractive index is 1.5. to O.Oli. D2 is 

modified profile 2, etc. 

J 

~ • E 

=> 

4 

3 

2 

I 

- 30 - 20 - 10 0 10 20 130 - 20 - 10 0 10 20 30 

"'" Error 

Model 300·2 - _ _ n=O.O i 

-- n=0.05i 

9 ST S T 

\ 

\ 

B ~ 

\ 

\ 

\ 

1: \ 

E \ , 6 z 

• 

~ 5 J 

~ . 4 ~ 

E 

=> 3 , 2 

I 

- 30 -20 - 10 0 '0 20 1 30 -20 - '0 0 10 20 ±30 - 20 - '0 0 10 20 30 

Figure 45.--Effect of 

stratosphere; Haze L, 

are given on figure . 

% Error 

changing aerosol absorption refractive index. Haze H, 

troposphere; i maginary terms for aerosol refractive index n 

Aerosol profiles are fixed. 

67 
4.1.2 Summary 

Even though we have included a wide variety of aerosol characteristics in our 

treatment of their error effects on Umkehr ozone profiles, we note that there is a 

commonality in the features of the errors in the deduced ozone profiles . Both 

stratospheric and tropospheric aerosols tend to (1) induce a s ignificant negative 

ozone error in the uppermost layers 7-9; (2) induce a small, usually negative 

ozone error in layers 3 to 6, and (3) induce a significant positive ozone erro r in 

layers 1 and 2 . Compared to tropospheric aerosols, stratospheric aerosols are 

much more effective in produc ing errors on the deduced ozone profiles. Tropospheric aerosols induce a small negative ozone error on the order of 2% to 5% in 

layer 9 (the region of importance in ozone production), whereas stratospheric 

aerosols induce errors of 10% to 20% in the same layer. 

In all cases studied, multiple scattering tended to reduce the magnitude of 

primary scattering estimat es of the haze effect. This encouraging result means 

that we need not be as concerned with tropospheric aerosols as previously thought; 

however, this does not preclude the utility of deriving some correctional schemes 

for tropospheric aerosols to improve the accura cy of the Umkehr method. Stratos pheric aerosols, on the other hand, mu st be considered as serious to the Umkehr 

measure ment when optica l depths are abnormally high, which is normally a consequence of significant volcanic activity. Again, correctional schemes for stratospheric aerosols may improve the accuracy of the Umkehr measurement, but the 

extent of the improvement will rely heavily on the accuracy of the measurement of 

stratospheric aerosols themselves. Aerosol optical depth is the most important 

variable. 

Finally, a few calculations that were performed to examine the aerosol error 

on the new shortened multiwavelength version of the Umkehr measurement (now in the 

process of development) indicate that the ozone profile errors for this method 

possess the same characteristics as those for the standard Umkehr method. The 

magnitudes of these errors seem to be slightly s maller, but it is too soon to be 

certain that this would be true for all conditions . 

4.2 Disparities in Ozone Measurement 

Figure 46 shows a plot of DeLuisi's (1975) ozone data in terms of departures 

from a mean of 0.294 (atm-cm vs. A for every 0.2 nm, beginning at 298.1 nm and 

ending at 319.5 nm. The mean total ozone was calculated from all data not exceeding 313.0 nm, because total ozone determinations became intolerably noisy beyond 

this wavelength; that is, ozone optical depth becomes comparable to the Rayleigh 

and aerosol optical depths. It was also necessary to eliminate a few data points 

at wavelengths above 313.0 nm because they displayed high standard deviations 

related to occasional spurious signals in the measurement system. Finally, a 

three-point unweighted smoother was applied to the entire set of data. The smoother 

had little effect on reducing the magnitude of the maxima and minima at wavelengths 

less than 310.0 nm. 

The variations in the total ozone at different wavelengths seem to display 

occasional positive correlation with the variations in the UV spectra at the same 

or nearly corresponding wavelengths. If there is some definite relationship, it 

is puzzling because the Langley method for obtaining optical depth is thought to 

be independent of the wavelength structure of the incident solar UV radiation 

source. The deeper and wider Fraunhofer line structure (where deduced ozone seems 

68 
E 

y 

E 

+0 04.--------.-------,-------.--------r-----~ 

+0.03 

+0.02 

3055 

+0.01 \ 3114 

3066 

3176 

~ Or_----~~r_f4r_-4---\_--~--~~~--~~~~--~ 

g \ N 

o 3125 

-0.01 

-0.02 

-0.03 

-0.04'-------L _____ ......l. ______ -'-_____ -L ___ __ ---' 

295 300 305 310 315 320 

X (nm) 

Figure 46.--Plot of DeLuisi's (1975) ozone data, in terms of departures from a 

mean of 0.294 atm-cm vs. A at 0.2-nm intervals beginning at 298.1 nm and ending at 

319.5 nm. Spectrometer bandpass is 1 . 0 nm. The mean total ozone was derived from 

all ozone values for wavelengths <3. 13.0 nm. 

to be mo st affected) may be responsible in some way for producing an apparent 

ambiguity; e.g., a significant Ring effect (Brinkman, 1968) might reduce the 

magni tude of the slope of a Langley plot, thereby resulting in a lower value of 

total ozone deduced from the slope. This could produce a positive correlation 

between total ozone and the extraterrestrial spectrum. 

4 .3 Selection of CO 2 Values from Whole Air Samples 

An algorithm for selecting CO 2 concentration values from whole air sampl es 

was based on two assumptions: 

(1) Independence of flask values obtained with at least 2-day separation. 

We assume the statistical independence of the residuals of means of 

flask pairs about a least squares polynomial fit of degree one through 

five. 

(2) Normality of the same residuals. 

These assumptions are shown to be valid for CO2 concentrations at MLO and BRW . At 

these stations minute mean values from continuous analyzer records were used from 

69 
about the same time interval as for flas k samples. In addition, the residual sum 

of squares for the fitted polynomials was ca l cula ted from the conti nuous data and 

used as an estimate of the "pure error" s um of squares. 

A schemati c diagram of the CO 2 se lection scheme i s shown in fig. 47. Because 

of serial correlation , paired CO 2 values are averaged unless they exceed 3 ppm, a 

value unlikely to result from rea l CO 2 concentration f lu c tuations. If the pair 

values differed by more than 3 ppm, they are probably independent b ecause of 

experimental error . The values are fitted to a poly nomial of degree one. Residuals 

are tested for normality by compa ring their s kewness with that of the Biometrika 

tables for 1% point (Pearson and Hartl ey , 1966). If the skewne ss of t he residuals 

exceeds the Biometrika v alue for the same number of sampl e points, the largest 

absolute residual is removed and t he fit is redone. Wh en this procedure yields an 

acceptable value for s kewness, the residual sum of squa res is tested against the 

"pure error" s um of squares explained above . If the F t est fails (i.e., the 

fitted s um of squares i s s i gnificantly larger than the s um of s quares found to be 

appropriate for a good fit), then a l l data points are r estored and the fitted 

polynomial degree is increased by one. The procedure is continued until the 

residuals are acceptab ly normal and the unexpla ined va riance is at an acceptable 

level. 

Average pairs with 

differences, 11, 

smaller than 

given value 

Compare residual sum 

of squares to "pure 

error" s um of squares 

t 

F test for adeq uacy 

of f i t 

P~ss 

I 

Finish 

FLASK DATA SELECTION SC HEME 

Flas k data 

taken in pairs 

Degree = 1 

f 

Fit pol ynomial of gi ve n 

degree to available 

flask va lue s 

Ca l culate residua ls 

for flask values 

t 

Te st of whether the re sidual s 

(pa ss ) approach a normal distribution 

(fa il) 

Remove flask val ue corresponding 

to largest residual 

Fail 

Degree of polynomial increased 

by l. Bring back original data 

IFigure 47.--Algorithm for se l ecting CO 2 va lues obta ined from fl as k samples of air. 

70 
4.3.1 Number of Flasks Sampled at One Time 

The data selection scheme, used with artificial data, was 

2 ITT 

CO 2 = 330 + 3 sin 365 + RV 

where T is time in days and RV is a random variable having two components. The 

first compone nt is a random variable having mea n 0 and standard deviation 0.3; the 

probability of this comp onent occurring is 0.B7. The second component is a 

random variable having the mean 1 and standard deviation 1 in case 1 and mean 2 

and s t andard deviation 1 in case 2. The samp l i ng was simulated by a monte-carlo 

technique usin g a total of 20B original points for pair sampling and 207 original 

points for triple sampling . 

Since the individual samp l es were compo sed of independent 

se l ect ion scheme did not average individual samples as above. 

s qua r es from the function 

330 + 3 2 ITT sin 365 

variables, the 

The mean sum of 

wa s ca l c ulated for each trial. Since the total number of sampl ings was about the 

same, the triple sampling was done two-thirds as many times as pair sampling . 

Tabl e 26 s hows the results for cases 1 and 2. Abou t 50 trials were used for each 

Table 26. --Flas h selec t ion of CO 2 data*t 

Case 1: RV' = N(l,n 

No. of flasks 

% of origina l 

Mean s um of sq. 

Trials 

Case 2: RV' = N(2,2) 

No. of flasks 

% of original 

ea n s um of sq. 

Tri als 

Pair sampling 

(20B original points) 

196 ± 4 

94.2 

0.15 ± 0.03 

49 

IB9 ± 6 

90 . 9 

0.19±0.1l 

51 

*C02 = 330 + 3 sin 2ITT + RV 

365 

RV = N (0,0.3) p = 0.B3 

RV = RV' P = 0.17 

t95% confidence intervals are given. 

71 

Triple sampling 

(207 original points) 

194 ± 4 

93.7 

0.26 ± 0.13 

46 

1B4 ± 6 

BB.9 

0.46 ± 0.34 

52 
case for both triple and pair sampling, and the results show that approximately 

the same number of samples are chosen regardless of pair or triple sampling. This 

approximate equa lity is caused by the effort of the selection scheme to save 

individual CO 2 value paired differences that exceed a preassigned value. 

4.3.2 Data Comparison between Flask Selected and Continuous Analyzer Data 

A continuous data set different from those examined above and corresponding 

to 1 year of flask data was examined. The flask data from tlLO were selected as 

described above and presented in fig. 48. Since the collections were made at 

about the same time each sampling day, hourly mean values from the continuous CO 2 

analyzer re cord from the same sampling time for every day of the year were used 

for comparison. Those hourly mean values are s hown in fig. 49. The comp arison 

technique wa s the extra sum of squares principle described by Draper and Smith 

(1966). 

The null hypothesis used was that there is no difference in the st r ucture of 

the data se ries. The null hypothesis could not be rejected at the 95% confidence 

level, and the approximate equiva lence of the flask data to the hourly mean data 

led us to confirm the value of the data selection scheme. 

1971 Mauna Loa FInk CO~ Dala 

329 5~ 32115~ 

32B.3 328.3 r-

• 

~ ! 

1977 Maun, l oa COnllnuous CO2 0.111 

. . 

':,,!', 

, 

:' 

'. 0" , 

-

.e 3212 

§ ; 321.1 1-

• .. - • ! 8 326.0 

o . u 

-

324.9 ~ -

=h I r ~------------~"~9------------~~~2~----~~~ Do, 

Figure 48 .--Mean concentrations of CO2 

for pairs of flask air samples taken at 

MLO in 1977. 

, 

~ g . " • ~325 :.': :.' ,: - o ..... 

u .:: :.: ~ 

324.6 -

Do, 

Figure 49 .--Hourly mean values for the 

time of flask sampling at MLO in 1977. 

72 

-
4.4 Analysis of North Carolina Turbidity Data 

In 1960, R . A. McCormick established a national tu r bidity network, with 

support from the U.S . Environmental Protection Agency (EPA) a nd NOAA, to provide 

data on the geographical, seasonal, and long term var ia tions of atmospheric 

aerosols (Flowers et al . , 19 69). Turbidity, or aerosol optical thickness, is 

indirectly obtained from measurements of direct solar beam intensity and has been 

customarily computed on the decadic ba se . While standardizing a nd ca librating 

network instrume nts , some 8 , 500 turbidity observations were obtained at Raleigh, 

N.C., from July 1969 through July 1975. This comprehensive 6 - yr data set of 

turbidity values was analyzed for with in-day, day-to-day, a nd year-to-year varia -

tions and f or dependnece on me t eorological parameters . A full report of the 

analyses is i n press (Peterson e t al., 1981 ) . 

Table 27 summarized the 1969- 1976 Raleigh turbidity measuremen ts. A very 

wide range of values was detected in both instantaneous measurements and monthly 

averages. The a nnual average of 0.147 is near the highest nonurban turd i d ity 

value in the United Sta t es . 

A distinct diurna l turbidity cyc l e was most pronounced i n winter and least in 

summer. The daily maximum occurred in early afternoon. The early morning minimum 

was slightly less than the late afternoon minimum. Although we could not identify 

the specific ca use of this cycle from available data, we believe that the cycle is 

a real atmospheric feature rather than an instrumental artifact. 

Table 27.--Summary of atmospheric turbidity (B) and vertical transmission (T) at 

500-nm wavelength for Raleigh, N.C ., 1969 - 1976 

B T Remarks 

0 0.855 Rayleigh scatt ering (t ) and ozone absorption 

(t ) only (t = 0.063, t = 0.005) z r z 

0 . 010 0.836 ~1inimum observed value (approx. ) 

0.042 0.776 Smallest monthly average (Dec 1972) 

0.05 4 0 . 755 Dec average 

0.127 0.638 Smallest annual average (1971) 

0.147 0.610 Average annual average 

0.164 0.586 Largest annual average (1973) 

0.318 0 .411 Jul average 

0.433 0.3 16 Largest monthly average (Aug 1974) 

1.000 0.086 Maximum observed value (approx . ) 

73 
The very ext ensive data bas e allowed us to describe the annual turbidity 

cycle i n some detail. Monthly statistics s howed the well known general features 

of high turbidity and day-to-day variation during summer and l ow values and 

variation during winter. A cubic spline best fit to daily averages, which gave a 

conti nuous estimate of turbidity during the year , revealed an asymmetric annual 

cycle , with a fla t I-rna-long minimum centered on 1 January rising to a peaked 

ma x imum centere d on 1 August. 

The depe ndence o f turbid ity on meteorologica l conditions was investigated by 

comp aring individual observations with l ocal meteorologi ca l parameters and through 

c lass i fica tion of air mass traj ec tories . Turbidity s howed a slight dependence on 

s urface wind me asurements with higher val ues with lowest wind speeds. Aside from 

winter, hi ghest av e rage turb i dities occurred with southea st winds and lowest 

turbidities with e ither northeast or northwest wind s. A fair correlation was 

obtained between turbidity and relative humid i t y ; when relative humidity was less 

than 40%, turbidity averaged significantly less than when it was greater than 40% . 

The best correlations were during winter . A better moisture parameter for turbidity correlations was dew point. For all seasons, turbidity marked ly increased as 

dew point increased, with the most significant correlations during winter and 

spring. Correlations between turbidity and local visibility showed a pronounced 

increase for visibilities less than 7 mi, but an ambiguous visibility-turbidity 

depende nce for visibiliti es greater t han 7 mi . 

The dependence of turbid ity on synoptic air ma ss was investigated by using 

air mass traj ectorie s arriving at Raleigh. Independent of season, air masses with 

a southern origin had greater turbidities than air ma sses arriving from either 

north or west. Turbidity of an air mass significantly increased as its residence 

time over the continental United States increased. Finally, turbidity changed 

more rapidly with residence time during summer than during other seasons. 

Year-to-year turbidity changes were studied by combining the Raleigh (1969-

present), Greensboro, N.C. (1965-1976), and Raleigh-Durham airport (1972 -1975 and 

1979) records. Figure 50 illustrates the monthly average turbidities from these 

loca ti ons . There was a distinct s ummer increase through 1976 . Summer turbidities 

subsequently dec r eased , but a reduced measurement freque ncy partly obscured the 

significance of that decrease. Turbidity during winter has been largely unchanged . 

A linear regression analysis of annual averages for the complete record gave an 

18% per decade turbidity increase. 

0.5 r--,----.----,----,--,--,----,---,---,--,--.,-----,----.----,---, >-

ft3 e 0.4 

",0) 

a: a: w::J 

> f- 0.3 

"'u >-0: I ~O 2 f-a. 

Zen 

~~01 f-

--- Greensboro 

--Raleigh 

.. ...... Raleigh·Durham 

/\ 

: \ l A \ r, , I 'VI " I, : \ 

~ .\ :\ n : ~I \ I, . , , 

\ I~ \ I \ /", I 

I I l I" \ 1 ' I \,_, \J \. I \/ 

t 

( 

I 

I 

I 

'" .O ~19~6-5-L----~1~9~6~7~----~19~6~9-L----~~9~7-~----~19~7~3-L----~~9~7~5~--~~19~7~7~----~1797=9~ 

Figure 50.--Monthly average atmospheric turbidity (500 - rum wavelength) at Greensboro, 

Raleigh, and Raleigh- Durham airport, N. C. 

74 
4.5 Barrow CO 2 , Aerosol , and Ozone Dependence on Air Tra j ectori es 

One aspect of the GNCC mea surement programs involves research into underst anding t he variability of those measur ements . A method we ha ve used for Barrow 

data is to link measured concentrations to air trajectories (Peterson et al., 

1980). This section s ummarizes t he research de scribed in that report. 

Daily average CO2 concentrations at Barrow for January through Ap ril 1977 and 

1978 are characterized by quasi-cyclical variations with amplitudes of 1 to 3 ppm. 

Ten CO 2 events were identified during these periods when con centration s significantly depa rted from t he s hort t erm average. To investigate a meteoro log i ca l 

caus e for these variations we obtained trajectories of ai r flow arriving a t Barrow 

using the method described by Hefter et al. (1975) . The trajectory calculations 

are ba sed on rawinsonde windspeed and direction meas ureme nts over the height 

interval 300 to 2,000 m above ground. Specific trajectories from 1 day of each of 

the 10 events are presented in fig. 51. Trajectory paths during the events were 

u sually persistent with s mall day-to-day variation. Days with above and below 

average CO 2 concentrations are represented by dashed and solid trajectory paths, 

respectively. The open circles indicate I-day travel time. The 5-day origin of 

fou r trajectories from the south was off the map . 

The traj ectories (fig. 5 1) are distinctly separated between those assoc iate d 

with hi gh and those with low CO 2 concentrations. All five cases with high CO 2 had 

a ssociated trajectories with air flowing from the Arc tic Basin. All air trajec -

tories associated with low CO2 concentrations came from t he south; four of these 

came out of the Gulf of Alaska. Synopti c me teo rologica l chart s f or these pe riods 

showed that the southerly air flow usua lly occurred in association with a well 

developed low pressure system (from the s u r face to 500 mb or highe r) in the Bering 

Sea-Aleutian region. 

Average daily condensation nucle i concent rations, aerosol light scattering 

coe fficients at 0.55-~ m wavelength, and ozone concentrations f or the 10 days 

75 

Figure 51.--Five- day trajectories of airfl ow arriving 

at Barrow, Alaska, on the 

indicated dates . Open circles indicate I-day travel 

time. Dashe d lines co rrespond to days with high 

CO 2 a t Barrow and solid 

lines to days with low CO2 , 
identified by fig. 51 trajectories were also computed. Every light scattering 

value associated with southerly trajectorie s is less than every value associated 

with northerly air flow. The same distribution is, true for condensation nuclei 

concentrations, excep t for one occurrence. In contrast, the ozone measurements 

have no dependence on the north-south trajectories. The largest po sitive and 

negative departures from monthly means, for example, both occur with northerly 

traj ectories. 

The higher concentr ations in air originating to the no rth imply a northern 

source of CO 2 , We s ugge s t two possibilities for such a sour ce. The first is the 

Arctic Ocean itself. Gosink and Kelley (personal communication) found that 

during winter CO 2 is transferred to the atmosphere through the annual sea ice, 

which can be quite porous because of brine channels. Thus, the wintertime Arctic 

s hould not be considere d as an ice-sealed passive surface with regard to exchange 

of gaseous carbon dioxide. 

A second possible source of CO 2 "north" of Barrow is advection to the Arctic 

from midlatitude anthropogenic sources, primarily the northeastern United States 

and western Europe. Rahn and McCaffrey (1980a) suggested such sources and pathways 

for aerosols, based on their measurements at Barrow and other Arctic locations. 

They believed that the elevated aerosol mass over the Arctic from De cember through 

April probably is caused by advection from midlatitude anthropogenic sources, 

especially European sour ces , to the Arctic . Our reported depende~ce of aerosol 

meas urements on north-south wind flow supports Rahn and McCa ffrey's hypothesis. 

Although the Arctic Ocean annual ice could be a natural pathway for CO2 to the 

atmo sphere, we do not know of any significant natural aerosol sources from the 

Arctic during winter. 

Our ozone mea s urements showed little dependence on trajectory or1g1n, suggesting either nonexistent or spatially uniform sources Qr sinks in the Alaskan-Arctic 

region at this time of year. Thus~ the fact that we see no trajectory direction 

dependence of ozone l ends significa nce to an argument for spatial non-uniformity 

of aerosol and CO 2 sources and sinks. 

In sunIDlary, we analyzed measurements of CO 2 , aerosol, and ozone from the 

base l ine observatory at Barrow, Alaska, in conjunction with low level trajectories 

of airflow arriving at Barrow. The CO2 and aerosol concentrations depended on 

trajectory origin; higher values occurred with airflow from the Ar ctic Basin than 

from the south. Ozone had no directional dependence. Thes e aerosol findings 

support the hypothesis that the origin of the Artic haze is anthropogenic. The 

CO 2 findings suggest two possible sources for the higher CO 2 concentrations: 

transfer from the ocean through annual sea ice to the Arctic atmosphere or advection to the Arctic from midlatitude anthropogenic sources by a mechanism similar 

to that of the Arctic haze. 

4.6 Intercomparison of mlcc and SIO CO 2 Neasurements at Mauna Loa 

The Scripps Institution of Oceanography (SIO) ha s operated a CO2 analyzer at 

Nauna Loa Observato ry since 1958 . GNCC ha s operated its own analyzer there since 

May 197 4 . During 1978 we began a program to directly intercompare the SIO and 

GNCC measurements through an exchange of data. Some first results are presented 

here. 

Average CO 2 concentrations were compiled for tho se hours when both SIO and 

GNCC determined that their records were free of local contamination. Then we 

76 
computed the GMCC minus SID differences by hour. Monthly summaries for 1976 are 

presented in table 28. The mean hourly difference, the standard deviation about 

that mean (SD) , and the number of hours of computed differences (N) are included 

for each month. A histogram of the January data is shown in fig. 52. 

The agreement between the two systems during 1976 was very good. Although 

the data from both systems were in the 1959 SID Adjusted Index Scale (no pressure 

broadening correction applied), they agree well in absolute va lue because the 

pressure broadening corrections for the SID (Applied Physics) and GMCC (URAS) 

instruments are similar (Pearman, 1977). Although the hourly differences averaged 

by month are very small, they did exhibit some small systematic variations related 

to the typical diurnal meteorological cycle at Mauna Loa. For example, the average 

nighttime differences were about 0.1 ppm greater than those during afternoon, and 

the differences with very dry air averaged about 0.15 ppm greater than those 

associated with highest dew points. Research is continuing into the cause of 

these small systematic differences since they indicate that the two systems do not 

respond similarly to some environmental factor. 

The long term difference between the systems is also under investigation. 

Although they agreed very well during 1976, there are indications of disagreement 

of about 1/2 ppm in subsequent years. This cooperative investigation with SID is 

being continued to determine possible causes for periods of disagreement and 

improve the overall data quality of both records. 

Table 28.--Comparison of 1976 Mauna Loa hourly average CO 2 measurements 

(GMCC minus Scripps, ppm) 

Month Mean SD N 

Jan -0.03 0.22 362 

Feb 0.00 0.21 379 

Mar -0.05 0.27 203 

Apr 0.21 0.22 264 

May 0 . 05 0.28 407 

Jun -0.08 0.18 345 

Jul 0.00 0.23 229 

Aug 0.01 0.23 251 

Sep 0.00 0.21 163 

Oct 0.03 0.27 229 

Nov 0.04 0.23 427 

Dec 0.13 0.21 348 

Ave. (less Apr) 0.01 3,343 

77 
100 

80 

en 

w 

() 

z 

w 60 a: 

a: 

::0 

() 

() 

0 40 LL 

0 

ci 

z 20 

0 

MAUNA LOA C02 COMPARISON 

JANUARY, 1976 

GMCC - SIO (PPM) 

Figu re 52.--Histogram of the number of 

occurrences at Mauna Loa GMCC minus SIO 

h ourl y CO 2 measurements, Three hundred 

sixty-two hourly differences from January 1976 are presented, 

4.7 Signatures in Atmospheric Transmission Variations 

at Mauna Loa Observatory, Hawaii, and Other Parts of the World 

Computation of clear sky atmospheric transmission from normal incident 

p yrheliometer measureme nts made at MLO from 1958 have been reported b y Ellis and 

Pueschel (1971) and Mendonca et al. ( 1978). In both studies secular trends in 

c l ear sky transmission and a well defined annual periodicity were observed (fig. 

53). The secular trend s were as much as two times larger than the annual variation and attributed to explosive volcanic ejections of ash and gases into the 

stra t osphere. 

The annual variation in transmission (late spring-early summer minimum in 

tra ns mission) was observed for the duration of the observation record regardless 

of whether volcanic explosions perturbed t he atmospheric transmission at irregular 

intervals. When the Mauna Loa record is examined for long term secular trends in 

t ransmission, an obvious signature is not evident. If the volcanic perturbations 

are overlooked, a very gradual long term decrease (~0.2%) can be discerned from 

1958 to 1976. But in 1977 the transmission values are as high or higher than 

those measu red in 1958 to 1960. 

I n fig. 54 the annual amplitude of t he atmospheric transmission for ~tauna Loa 

is plotted with time, after the perturbations in transmission from volcanic 

event s have been subtracted from the record. A general upward trend in amplitude 

i s observed. Although the magnitude of t he increase in annual amplitude is small 

~1 .0%), t he percentage incre ase ~50%) is significant. 

To investigate whether similar trends exist elsewhere, data were examined 

f rom t he United States and the Orient, which are the nearest continental land 

masses to Mauna Loa. 

Figu re 55 shows a plot of atmospheric turbidity for winter and s ummer and the 

difference between the two (annual amplitude) for several stations in the continent al United States. An upward trend in the annual amplitude of turbidity is 

evide nt, and an inc rease in summer values is the primary cause for the increase in 

annual amplitude with time. 

78 
94r-----------------------------------------, 

12 month funning mean 

.92 

91 o 

g> ~ 

"0' 

Q ~ < 

60 

YEAR 

20 km 

10km 

Figure 53.--Six-mo and 12-mo smoothing of Mauna Loa transmission values for 20-yr 

record. Episodic explosive volcanic erupt ions are listed on bottom for t he 

record period. Heights of the arrows designate the atmos pheric height that t he 

visible volcanic cloud reached. The 12-mo running mean plot shows the secul ar 

perturbations in transmission. The 6-mo running mean plot shows the annual 

variation as well as the secular trends. Several sharp dec reases are seen in 

the trace after Agung, Awu, and DeFuego. From the pre-Agung period to 1976 t he 

upper enve lope of the trace suggests a gradual decrease in transmission, but i n 

1977 the transmissions recove r and arc as high or higher than during the preAgung pe riod. 

02 

§ 

" , 

, 

, 

r 

<l 

O. 

Annual Amplitude Vert.eJI Tt,lIb.dlly 

Mauna Loa 

1975 

030: o 

-, 

'" , 

02 '" <l 

" 

Figure 54.--The annual variation in atmospheric transmission and turbidity is 

plotted with time. The annual variations (~T and ~~) are obtained by taking the 

difference between winter and spring values. The line trace was obtained by using 

the transmission values from Mendonca et al . (1978); the dots are obtained f r om 

Volz turbidity measurements at NLO. The wide scatter in the turbidity data in 

the later years may be partially caused by instruments. The upward trend in t he 

amplitude of transmission is detectable especially in the later years . 

79 
.J 

.. 

.J 

.2 

§ 

• > 

.. .. 

Huron, S.D. 

M ,noul •• Mont 

St. Clolld. Minn. 

M"Id"n, Miu. 

Summer 

~t, 

"" 1970 1975 1965 

NNi Yofk. N.Y. 

YOU"'1'lown, 01'''0 

B.lumore. Md. 

Lillie Roc~ . Ar~ . 

Memphll. Tann, 

Greensboro. N.C 

Topeka, Kin ... 

Green Bay, Wit, 

1970 1975 

Figure 55.--Plots of Volz turbidity measurements for two groups 

of U.S. stations, showing trend 

in turbidity with time. Top and 

bottom curves are for summer and 

winter, respectively. The difference of the two (~~) is the annual 

amplitude. 

When the annual variation of vertical atmospheric turbidity is examined for 

Mauna Loa and the two sections of the continental United States, different signatures are evident (fig. 56). Stations in the eastern United States have the 

highest turbidity, standard deviations, and annual amplitude, as would be expected 

for measurements near a source region. As the measurements progress westward to 

middle America the annual amplitude decreases and the maximum shifts toward 

spring, with smaller standard deviations. This appears to be a feature of cleaner 

sites . 

In fig. 57 a comparison between the annual variation of atmospheric transmission between Asia and Mauna Loa is shown. In contrast to the comparison between 

Mauna Loa and the continental United States, the annual transmission variations in 

fig. 57 are in phase. The transparency of the atmosphere has been determined by 

several methods with the same results. 

8,Uimo<t 

Vourlvnown 

'Mm!)hll 

Merldiln 

N .... VOlk 

GrNn BIY 

linl. Rock 

G,"n!bo'Q 

1\ 

'--Huron. SoD 

M,uoul. 

T~k. 

SI. Cloud " CO 

. ../ 

• 

Annu,' V,fll.lon 

VtrhUrl Tu rb ldl\Y 

IVa', Inn,., 

• 

80 

Figure 56.--Average monthly 

turbidities and standard deviation for three groups of stations. 
'" V.nul Col~mn 1,,(1) ,HV ..... . ~ •• I.or,H.kl 

11 9 ... -1 

IS V") 

"" 

'" ~ , 

~ 

921 Figure '" 57.--Average seasonal var-

'" "'LO IT,an .. ' iations in turbidity for Mauna lOY" Loa and Asia. The Mauna Loa 

0 '" '" '" transmission values and Volz :; 930 g 

, turbidity measurements are com-

'" 024 § pared with atmospheric turbidity MlO . '" III .... 1.' , values determined from silver II,,, '" ~ 

'" '" disc pyrheliometer mea s urements 

". made i n Japan, Korea, and China 

(Yamamoto et al. , 1968). Sum .... ' h ll 

The annual ampl itude of vertica l turbid ity for several stations in Japan is 

presented in fig. 58 . Although the scatter is large, an increasing t rend in 

annua l amplitude i s also dis ce rned from t he record. The increase in annual 

amplitude for Japan is more pronounced from the 1950's to t he present than for the 

earlier years . Yamamoto et al. (1968) s uggest that t he decrease in industrial 

activity in Japa n i mmediately after World War II explains the decrease in turbidity in that period. 

From al l nata examined the annu a l amplitude i n atmospheric transparency s hows 

an increasing trend with time from the 1950's in the eastern and central United 

States , Mauna Loa, and east Asia. The i n crease in annual amplitude results mainly 

f rom a n increase in turbidity in s ummer or spring, when turbidity is at t h e annual 

maximum. Whether t his long term increase in s ummer a nd spring results from increases in industrial activity couple d with the greater atmospheric vertical 

mixing and con sequ e ntial lon ger aeroso l residence time (spring-summer) mu st still 

be examined. If industrial activity contributes to the increa sing turbidities i n 

summer and spring , the n gas-t o-partic le conversions with increased sunlight and 

vertica l moisture convection at these times could a l so add to t h e long term turbidity increases in summer and sprin g. 

,,~" Apr .. July - boo. Ckl . 

u.1r.a An""ll Amplilude Ver\le~1 TurbldllY 

Shimizu 

M.I''''''IOIO 

Aim. 

To\yo 

Sippa.o 

81 

Figure 58.--The annual amplitude in atmospheric turbidity over Japan is plotted with time . The ordinate scale is a 

rela t ive measurement of the annual amplitude. 
5. COOPERATIVE PROGRAMS 

5. 1 Air Chemistry Studies at Barrow During 1979 

Kenneth A. Rahn 

University of Rhode Island 

Kingston, RI 02881 

During 1979 the University of Rhode Island continued to study air chemistry 

at Barrow . Routine 4-day high volume samples of the near surface aerosol were 

taken throughout the year. In September, the fourth consecutive year of such 

sampling began . 

In July and August, an improved, expanded relay box for the sample control 

system was installed by R. J. McCa ffrey, designed to accept multiple high and l ow 

volume samplers simultaneousl y, and operate them in nearly any combination of 

clean sector, dirty sector, and continuolls sampling . At the same time, a second 

high vo lume aerosol sampler, identi ca l to the first, was installed, to allow us to 

take samples for othe r r esea rchers, or t o t a ke different types of samples simultaneously. A problem in the sector control box was discovered in August and 

rectified at URI during fall. The entire control system was put into operation in 

December. We now have a mini sampling center at BRW that H. Rosen of LBL has used 

for his low vo lume sampling of carbonaceous aerosol. 

In Summary Report 1978 w~ presented data from our 1976-77 samples; this year, 

we s how data (fig. 59 ) f or SO~, y, and 210Pb for individual samples of 1977-78 

(Rahn and McCaffrey, 1980a). SO~ and V, which we believe are derived from distant 

pollution sources, show similar patterns to thos e of 1976-77, with a spring maximum 

superimposed on a broader winter plateau. SO~ decreases some weeks later in 

spring than does the V. Both show pronounced quasi-monthly cycles of concentration. 

10.0 

1.0 

0 .1 

0.0 1 

0 .001 

" 

BARROW, ALASKA 

1977-78 

EXCESS (NONCRUSTAL) V, ng m- 3 

1 15 1 15 15 15 1 15 1 15 15 15 15 

SEPT 77 OCT NOV DEC JAN 78 FE8 MAR APR MAY 

15 15 

JUN JUL 

15 

AUG 

Figure 59 .--Concentrations of noncrustal V, norunarine sulfate, and 210Pb i n 

individual filter sample s at Barrow, Alaska, during 1977-78. Monthly mean 

concentrations of 210Pb at Barrow during 1975-76 (EML) are given for comparison. 

(After Hahn and McCaffrey, 1980a) . 

82 
Both our 210Pb data for individual samples and earlier 210Pb data from Environmental Neasurements Laboratory (monthly means) agree in magnitude and point to a 

nearly level winter plateau beginning in November. This rapid early rise is 

probably related to the early peak of the precursor 222Rn. 

Several special experiments were conducted at BRW during 1979 by our group 

and in cooperation with other groups. In Narch and August-September, aeroso l 

samples were taken on glass fiber filters for J. Daisey of NYU for organic analysis. 

Her results have shown that organic matter is probably the second most abundant 

constituent of the Arctic winter submicron aerosol, and that its sources are 

different from winter to summer. Portions of her extracts have been analyzed by 

C. Weschler of Bell Laboratories; among the most interesting of his results is the 

presence of high concentrations of silicones. 

From 31 Narch through 14 April, aerosol was sampled simultaneously at BRW and 

Narwahl Island, a remote location 30 km north of Prudhoe Bay, to check the regional 

representativity of the clean sector of the Barrow atmo sphere. T. J. Conway of 

URI undertook this experiment in response to suggestions that the high concentrations of aerosol at Barrow, even in its clean sector, were from Barrow itself and 

not representative of the North American Arctic in general. The Narwahl Island 

site was upwind of all human activity when the winds came from the north, and 

hence was considered the baseline. The results showed conclusive ly that Barrow 

clean sector ~ir truly represents the Alaskan Arctic air. Concentrations of the 

pollutants SO~ and V were nearly the same at BRW and Narwahl. Filters from both 

locations were equally gray (from sooty carbon) and could not be told apart by 

eye. These results give confidence to comparisons between data from Barrow and 

tho se from other Arctic locations. _One example of such a comparison is the map of 

typical winter concentrations of SO~ shown in fig. 60 (Rahn and McCaffrey, 1980a), 

which shows sulfate on both sides of the Arctic. 

From 27 July to 7 August, R. D. Borys of Colorado State University took a 

series of aerosol samples at Barrow, as part of a six site study of cloud active 

aerosol (cloud condensation nuclei and ice nuclei) in and around the Arctic. This 

work will form the bulk of his Ph.D. thesis. 

Beginning in August, we obtained a series of measurements of fluxes of 222Rn 

from the tundra and ambient concentrations of 222Rn, through a cooperative experiment between R. J. McCaffrey and EML in New York. Fluxes were measured by absorbing the 222Rn in activated charcoal cannisters mounted on pipes driven into the 

tundra. The results, which are still uncertain because of slow mail service 

betweeen Barrow and New York, show very low fluxes of roughly 1 to 7 atto Ci 

cm- 2s- 1 . Comparable values in New Jersey are 40 to 100 atto Ci cm- 2s- 1, decreasing to roughly 5 atto Ci cm- 2s- 1 when the ground is frozen. By contrast, the 

atmospheric concentrations of 222Rn were 20 to 70 pCi m- 3 (2-wk averages), the 

highest yet measured for coastal regions of Alaska. Figure 61 shows that Barrow 

has the same fall maximum reported earlier for Kodiak and Wales, Alaska, but 

higher concentrations. These data are consistent with an Alaskan source to the 

south or a distant source to the north; more detailed experiments will be required 

to reveal which explanation is correct. 

In December we began a program to sample daily the Barrow aerosol with the 

second high volume sample r. This project had several purposes: to better correlate our results with GMCC data and the NOAA trajectories to Barrow, to compare 

concentrations with locations of air masses and synoptic systems near Barrow, and 

to investigate the relative amplitudes of the various temporal cycles of the 

aerosol at Barrow. The experiment will be repeated during winter 1980-81. 

83 
Figure 60.--Winter concentrations of 

nonmarine sulfate, fJg m -3. (After Rahn 

and McCaffrey, 1980a). 

70 

60 

50 

~lE 40 

30 

20 

10 

6-------10. Barrow (1979 - 80) 

0--0 Wales (1953 - 59) 

__ Kodiak (1950 - 60) 

Figure 61.--l'1onthly mean concentra tions 

of the continental gas 222Rn at Barrow 

and two other Alaskan sites. Wales and 

Kodiak data are from Lockhart (1962). 

5.2 Soot in the Arctic 

H. Rosen and T. Novakov 

University of California 

Berkeley, CA 94720 

A sampling program for characterizing the carbonaceous aerosol was started in 

August 1979 in Barrow, Alaska. The preliminary results of this study show the 

following important features: 

(1) The concentrations of the aerosol particles dramatically increase from 

fall to early spring with the levels of carbonaceous particles approaching 2 fJg m- 3 

which is only about a factor of 4 less than the loadings typically found in urban 

environments . 

(2) The Arctic haze contains a large graphitic component, which in the 

spring can ac count for approximately 40% of the carbonaceous mass . This component 

can only be produced by combustion processes, and therefore, if forest fires 

ignored, it must have an anthropogenic origin. 

(3) Graphitic carbon has a large optical absorptivity, evidenced by the grey 

or black appearance of the filter deposits. The magnitude of the absorption 

coefficient b b during the spring is approximately 5 x 10- 6 m- 1 , which could be 

climatically ~lgnificant if the absorbing species extends over several kilometers 

84 
in height. Visual obse rvation (Mitchell, 1956) from airplane flights indicates 

that the Arctic haze extends up to 10 km. A simple model calculation us ing the 

two stream approximation of Chylek and Coakley and assuming a 10-km pathl ength and 

a snow albedo of 0.8 yields a change in the planetary albedo of 10%, whi ch is 

quite large and may significantly affect the heat balance over the Arctic region 

(Shaw and Stamnes, 1980). 

(4) The ratio of total carbon to sulfate content of the aerosol a t Barrow is 

similar t o that found for Brosset's ( 1979) bla ck episodes in Sweden, which have 

been postulated as resulting from long range transport. The Ar c tic haz e may be 

due t o a continuation of this transport proce ss, as suggested by Rahn and McCaffrey 

(1980b). 

(5) Results obtained with samples collected with and without a wind controller suggest that there is no signifi cant contamination from local sources. 

Further, aerosol samp l es collected a t other sites across the Arctic (Mould Bay, 

Spitzbergen) seem to show the same genera l features as those collected at Barrow 

(Barrie et al., 1980; Ottar et a l., 1980). 

These preliminary observations suggest that antropogenically generated aeroso l 

concentrations comparab l e to those found at urban lo ca tions can develop even in 

remote environments. 

An aerosol sampler was designed and constructed at Lawrence Berkeley Laboratory to collect parallel filter sampl es on 47-mm quartz fiber and millipore substrates at a flowrate of approximatel y 1 .5 cfm . The sampler was put into opera t ion 

on 18 October 1979 and coupled to a wind controller on 7 January 1980, to minimize 

local contamination by collecting samp les only when the wind was blowing from the 

clean air sector. Approximately 50 filter pairs have been collected at sampling 

time intervals ranging between 2 days and 1 we e k . All these filters have been 

analyzed to determine the total carbon content of the aerosol, the absorption 

coefficient of the aerosol, and the concentration of e lements with Z > 11 by the 

X-ray fluorescence technique. Only selected filt ers have been analyzed by Raman 

spectroscopy and opticothermal analysis. 

Raman spectroscopy was applied to the analysis of several samples coll ected 

at Barrow . The results are shown in fig. 62, where the spectrum of a n Arctic ha ze 

sample is comp ared to that of urban particulates, various source emissions, and 

carbon black. All these spectra show the presence of t wo intense Raman modes 

l ocated at 1 ,35 0 and 1,600 cm- i , which have been identified as resulting from 

phonons p ropagating with graphitic planes. This result shows that graphitic 

structures simi lar t o carbon bla ck and caused by combustion processes are present 

in the Arctic aerosol . Further, the large intensity in these modes i nd icates that 

the graphitic structures represent a major component of the aerosol. 

The filters coll ect ed at Barrow from fall through late spring have a grey or 

black appearance similar to tha t found for urban particulates . For the urban 

samples, this optica lly absorbing component has been identifie d as the graphitic 

species determined by Raman s pectroscopy (Ro sen et a l., 1978) . For the Arctic 

samples, a similar identification is presumably valid but needs to be te sted. 

Pre liminary measurement on a limited number of sample s s hows that the optically 

absorbing species has a l /A wavelength dependence , is insoluble in a wide range of 

solvents, and has a high temperature stability with an oxidation threshold of 

approximately 500°C. These results are consistent with the properties of graphitic 

carbon and strongly suggest that the optically abso rbing species at Barrow is 

graphitic. 

85 
I 

Arctic 

haze 

St. Louis, 

11; ssouri 

T 

" 

. ' -

. . . 0,/. 

"~." .. ::-... : .. ...... :: ..... '.-

,,:.:," 

.f.. 

.. ' \. Car 

.;/ \....) 

"'" , .......,,,,,,' 

~ Diese l 

.' 

, '. 

'. 

' . 

, 

-, 

'-~ 

.-

Carbon 

bl ack \ .... ,j 

\ ..... --....... --

Graph; te 

1000 'zoo 1400 1600 1800 

..... ':" 

Figure 62 . --Raman spectra between 920 

and 1,950 cm- 1 of Ar ctic haze, urban, 

and various source particulate sample s . 

86 
9.-,,--,-,~--,--,--.-,,--.--,--,-,-,-, 

Barrow (1979- 1980) • 

• 

July AUQ_ Sept Oct Nov. Dec. June Feb. Menh A9rll May June 

Figure 63.--Biweekly averages of absorption coefficient at Barrow from 

October 1979 through May 1980. 

The variation of the optical absorptivity (or graphitic carbon concentra tion) 

of the Barrow aerosol is rather dramatic (fig. 63). The absorption coefficient 

changes by about an order of magnitude from early Novembe r to earl y January and 

remains at a relatively high level throughout most of February, March, and Ap r il. 

It decreases substantially in May . The magnitude of the absorption coeffi c i ent 

during winter and spring is comparable to that found in urban environments (i .e ., 

about a factor of 5 less than Berkeley and Denver and a factor of 10 less than New 

York) and appears to be an areawide phenomenon with similar annual variations 

occurring at widely spaced sites across the Arctic (Mould Bay, Spitzbergen) (Ba rrie 

et al., 1980; attar et al., 1980) ; see fig. 64. 

.0 

a 

'" '" or 

c 

"'" u 

o 

ID 

Borrow (l979-19BO) ~)\ 

/ ~ ~ 

~ V\ I -1 J \.- , , , , , 

July Au\!. Sept Ocl. Nov. Dec. Jon Feb. Morch Apr. May June 

87 

Figure 64.--Comparison between seasona l 

variation in blac kness of filter depo sits collected at Barrow, Al aska, and 

Mould Bay, Canada, in 1979 and 1980. 

Mould Bay samples were p rovided by 

L. A. Barrie and R. M. Hoff of the 

Canadian Atmospheric Envi ronment Science. 
40r--.--,---r--.--,---r--.--,---r-----, 

c 

~ 

~ ~ 2" 30 

c 

o 

<> 

;; 

u 

u 

".;: 20 

i 

E 

'" 

10 

0- Biweekly overoges 

Bo rr ow 1979- 1980 

__ New York 

-- Los Angeles 

Oct Nov Dec Jon Feb M ar Apr Ma y June 

Figure 65.--Biweekly averages of the 

graphitic content as a percentage of 

the total carbon content of the Barrow 

aerosol from October 1979 through May 

1980. 

Using the optical constants of graphitic carbon determined from our urban 

studies, we can estimate the graphitic carbon concentration at Barrow. (Measurements are under way to test these determinations by an independent methodology.) 

These results are shown in fig. 65, where we plot the graphitic carbon concentration as a fraction of the total carbon content of the aerosol for various periods 

of time during the year. The results show a strong enrichment of the graphitic 

fraction of the carbonaceous aerosol from early to late winter. The concentration 

of graphitic carbon in late February is almost 40% of the carbonaceous mass. The 

percentage is higher than that found in urban centers like New York City and Los 

Angeles. After its peak in February, the fraction of graphitic carbon seems to 

level off to a value more typical of that in urban environments. 

5.3 Chemical Composition of Atmospheric Aerosols 

William H. Zol l er, William C. Cunningham, and Namik K. Aras 

University of Maryland 

College Park, MD 20742 

Our project was designed to mea sure the chemical composition of atmospheric 

particulate material in remote areas. Since different sources of airborne particulate material have different chemica l compositions, the important sources can be 

identified for a given location. Through these measurements we hope to observe 

changes in the chemical composition of remote aerosols that result from changes in 

the sources (seasonal variations or anthropogenit emissions) or in the mode of 

transport to remote areas. Measurements began in 1970 at the South Pole, and the 

record of aerosol chemical composition is nearly continuous from 1975. Measurements began in February 1979 at Mauna Loa Observatory. 

At present aerosols are collected on filters at each location using high 

volume vacuum pumps and a ll plastic sampling systems. Nuclepore, Fluropore, and 

Whatman 541 filters are currently used at the sampling sites along with Battelletype cascade impactors for particle sizing experiments. At SPO, sampling is 

controlled by a wind directional controller that allows sampling only when the 

wind is from the Clean Air Quadrant and windspeed exceeds 1.3 m s-l. The Clean 

Air Quadrant is defined as a 140o -wide area to the northeast of the station. The 

wind comes from this area almo st 90% of the time, and the quadrant is off limits 

to all vehicles and people to minimize contamination. 

88 
At MLO, we collected downslope samples between 2100 and 0500 and upslope 

between 0800 and 1800. During the day sunlight heats up the island's lava, which 

in turn heats up the air, making it rise up the slope of the volcano, and sea 

breezes transport sea salt up onto the higher areas. At night the island cools 

rapidly, and air flows down the mountain allowing clean air from above the boundary 

layer to flow over the station. Sample collection periods at SPO are 10 days and 

at MLO 7 days. Samples for shorter periods are occasionally collected, but because 

of the low concentration in clean, remote areas, only a few (10 to 15) elements 

can be determined above the filter blanks. All samples are analyzed by nondestructive neutron activation analysis for the trace elements, and soluble sulfate is 

determined by flash volatilization using flame photometric detection. 

5.3.1 South Pole Station 

Measurements have been taken at the South Pole almost continuously since the 

1974-75 austral summer season (Maenhaut et al., 1979; Cunningham, 1979; Zoller et 

al., 1979). The results of these measurements show that a relatively consistent 

pattern of atmospheric aerosol composition reflects changes in the transport 

mechanisms of aerosols into the interior of the Antarctic continent. The observed 

chemical composition variations can be compared with the known composition patterns 

of sources to identify some major aerosol contributors in the Antarctic: crustal 

dust, sea salt, meteorite burnup in the atmosphere, and tropospheric plus stratospheric sulfate. The source of the anomously enriched elements (Se, As, Sb, Zn, 

In, Pb, Cd, Au, Ag and Br) is unknown, or in doubt. These elements only account 

for a few percent of the total mass but are greatly enriche d over that expected 

for known sources of airborne particulates. A portion of these elements is believed to come from volcanic emissions and the ocean (Br). 

In fig. 66, the time variations for four austral summer seasons and two overwinter periods are shown. The variations are compared with those for 7Be, a 

radionuclide produced in the stratosphere that shows regular seasonal patterns 

related to the transport of stratospheric material into the troposphere and then 

into the interior of Antarctica. The results show that sulfate, crustal dust, and 

meteorite debris are correlated to 7Be in that they have higher concentrations in 

austral summer and significantly lower concentrations during winter. Sea salt, on 

the other hand, shows a significant increase during winter. Se does not show any 

significant variations during these periods, making it difficult to assess its 

sources or transport to Antarctica. For sulfate, the over-winter mass observed is 

corrected for the contribution of marine salts and in many cases is only an upper 

limit, since the l.evels were below the detection limit of the analytical procedures. 

The results in fig. 66 are calculated as follows for each component. 

Crustal dust: The mass of dust is calculated on the basis of the elements 

AI, V, and Sc, using the crustal composition pattern of Taylor. At first we also 

used Mn and Fe, but significant variations of these elements were observed on some 

samples which we found to be correlated with enhanced cobalt believed to be of 

meteoritic origin. 

Meteorite: Excess Co is used as the tracer of this component, but excess Fe, 

Mn, and occasionally Mg are also used to calculate the mass of this component, 

using the composition of average chondritic meteorites for comparison (B. Mason, 

personal communication, 1979). Of these elements, the ones with the greatest 

influence are Co and Fe. 

Sea salt: Sodium, the major element that indicates sea salt, is used to 

calculate the mass of this component after correction for its crustal contribution. 

89 
'" ". E 10 i- .... , . ..... ........ : Se - "- .' 

'" ...... a. If- -

1000 f- -

'" E " 'II' p'rP 

W "- " ~\'il,' Sulfcte_ 

'" 100 i- e: " " 

'" 10 i- - E f- - "- . \ 

'" ... ... , e: ,. ..... 01 . , Meteor _ i- .. " '. ' . . .. .. " " 10 I- 'I' '" - '" E x,: 'J. , ", , "- Crust " '" " , " e: - " Xx I: \ -

, " " ' 

100 - .. -

'" .: :. . . ,. .. E 10 .. Sec "- - . -

'" :. ... • . ... e: Figure 66.--Temporal variation of com- : - - ponents in the Antarctic atmosphere. 

OF OF 1975 OF 1976 OF 

71 75 76 78 

Other elements (K, Ca, and Mg) are used as checks, but uncertainties with respect 

to the ir possible fractionation at the sea surface and analytical uncertainties 

make their use questionable. 

Sulfate: Sulfur is measured and the sulfate mass i s calculated by assuming 

that all sulfur is present as S042-. Correction is made for marine source sulfa te, 

so that the ma ss given is for excess sulfate, whi ch is be l ieved to come from the 

stratosphere as well as troposphere. During winter, a majority of levels were 

below the sensitivity of neutron activation analysis and so only upper limits 

could be determined. In more recent studies, more sensitive analytical techniques 

have been employed. 

From the observed time variations of each comp onent and the meteorology of 

the region, a model of transport ha s been developed that shows a strong seasonal 

variation of the sources and the mode of transport to the interior of Antarctica. 

During the austral summer, transport is enhanced between the stratosphere and 

troposphere, causing the higher levels of 7Be, sulfate, and meteorite debris 

observed then . The mixing probably occurs nea r the margins of the Antarctic 

continent, and the air moves over the continent where it gradually mixes and 

diffuses toward the surface. During summer the entire area around and over 

Antarc tica i s relatively calm, with minimal storm activity, so that the sea salt 

has little cha nc e of mixing to an altitude high enough to be carried into the 

interior of Antarctica. The small amount of sea salt and the crustal dust that 

reaches the interior of Antarctica is believed to be transported through the upper 

tropo sphere from areas distant from the Antarctic. 

90 
The transport during the winter season is exactly the revers e, with exchange 

between the troposphere and stratosphere substantially reduced, while intense 

storm activity off the coast of An tarctica mixes sea salt into the upper tropos phere . Since passing weather systems tend t o circle the Antarcti c continent and 

not move toward the int erior, they ac t as a barrier to air masses moving to the 

south from the continenta l areas of Australia, Africa, and South America. This 

effect results in the washout or rainout of crustal dust being tra nsported toward 

Antarctica. Some sea salt aerosols are transpo rted to the upper areas of the 

tropos phere , where water vapor evaporates leaving sea salt particles t hat are then 

transported into the i nteri or of the Antarcti c continent by persistant air flows 

in the mid t o upper troposphere. Some of this sea salt then finds its way to the 

surface i n the interior and, in some cases , can be identifie d with large s torm 

activity off the coast as observed during fall 1979. 

5.3.2 Mauna Loa Observatory 

The results of the sample analyses from MLO are handle d simi l arly to those 

f or South Pole samples. We have comp ared the c l e anest conditions at ~ILO with 

summer conditions a t SPO. Table 29 s hows a comp arison of the concentrations of 

some elements associated with crustal dust or sea salt and a few anomously enr iched 

elements for each site. We have a l so included the winter and s ummer data for the 

South Pole and have calculated the ratios of some values. The downslope sulf ur 

l evels are comp arable with the South Pole s ummer results but are higher than the 

Table 29.--Mean atmospheric chemical concentrations of atmospheric aerosol 

Element South Pol e (all data) Mauna Loa (clean) DS/summer 

Summer* Wintert Downsl ope Upslope US/ OS 

S (ng m- S) 76±24 29±10 74±12 230±90 3. I 0.97 

Na (n m-s) 5. 1±1. 7 40±31 3 . 3±2.5 88±56 27 0.65 

Al (ng m-s) 0 .83±0.41 0.30±0.04 5.0±3.2 14±8 2.8 6.0 

Mn (pg m -s) 14±6 6.7±4 .5 85±65 190±1l0 2. 2 6.1 

V (pg m- S) 1. 6±0. 6 -0.9 1l±9 27±13 2 . 4 6.9 

As (pg m- S)** 24±7 17±3 23±20 1.4 0.71 

As (pg m-S)tt 8.4±1.1 17±9 

Se (pg m-s) 6.3±O.6 6.9±2.7 35±24 25±8 0.7 5.6 

Sb (pg m- S)** 2.0±1.6 6.6±2.9 5.8±3.3 0. 9 3.3 

Sb (pg m-S)tt O. 45±0.16 2.1±1.5 

* Average of four summers. 

tAverage of two winters. 

7-."* Nuclepore filters. 

ttWhatman 541 filters. 

91 
winter results. The upslope sulfur concentrations are higher by a factor of three 

than the downslope values because of the increase in sea salt sulfate. The downslope sodium values are also approximately the same as observed in Antarctica, 

whereas the upslope values are nearly 30 times higher. All crusta l elements (AI, 

Mn, and V) show downslope levels six times higher than during the average Antarctic 

summer season. These crustal elements also show an increase in the upslope samples 

presumably indicating soil derived particles from the Island of Hawaii itself. 

The volatile elements show some very startling differences. The concentrations observed in the upslope and downslope samples are essentially the same, 

showing no change with wind direction or meteorological conditions. The levels of 

As are very similar for spa and MLO, whereas Se and Sb levels are higher in Hawaii. 

The differences observed for the Whatman and Nuclepore filters are believed to be 

caused by the efficiency differences for these filters for small aerosols (Maenhaut 

et al., 1979). Since the winter Whatman samples have concentrations similar to 

the s ummer Nuclepore samples, it is tempting to suggest that the observed differences in the Whatman concentration during the summer and winter are caused by 

different scavenging me chanisms that occur during the colder seasons . The large 

increases in Se and Sb in Hawaii are very interesting. Although the number of 

observations during 'clean' conditions in Hawaii is small, one is tempted to 

suggest that the higher levels are caused by antropogenic production. A majority 

of anthropogenic emissions are in the Northern Hemisphere and these two elements 

(Se and Sb) are enriched in anthropogenic sources (Gladney et al., 1976; Greenberg 

et al., 1978, and Kowalczyk et al., 1978). 

Another important aspect of the measurements in Hawaii has been the identification of the source of the aerosols that cause hazy conditions each spring. 

These condi~ions aEe typified by a drastic increase in the light scattering 

(b = 10 7 ~ 10 5 m 1) without a comparable rise in the number of condensation 

scat nuclel. During 1979, we collected samples that showed that the large increase in 

the mass of the atmospheric aerosol at Hawaii results from an increase in the 

amount of crustal component usually observed. This relation is evidenced by the 

large increase in the crustal e lements such as AI, Mn, Fe, V, Sc, etc. Figure 67 

s hows the aerosol mass for crustal dust and salt during upslope samples collected 

in spring 1979. A similar plot for the downslope samples is shown in fig. 68. 

The downslope results show a similar increase in rustal mass with the highest 

concentration occurring in early May. The ma ss of the marine aerosol in the 

downslope samples is much lower than that in the upslope ones. The l arge increase 

in the downslope samples in early June appears to be caused by contamination of 

the site by winds during evening. This is confirmed by the chemistry of the 

aerosols, which is similar to that of the weathered island lava. There is some 

slight indication, because of excessive levels as As, that venting of Mauna Loa 

volcano may be partially responsible, but no substantial increase in Se or Sb was 

detected. To be more certain of the potential of the volcano to impact these 

samples, samples of gaseous and particulate emissions from Mauna Loa volcano 

should be collected and characterized for the minor and trace elements that are 

uniquely enriched by each volcano. 

The chemical composition of the dust during the April-May episode is significantly diffe rent from the chemistry of Hawaiian basalt and compares more favorably 

with that observed for desert dust. A more detailed comp arison is currently under 

way using the concentrations of more than 35 trace elements in the Hawaiian 

aerosol samples and desert dust samples from different areas of the world. It 

appears that the desert dust samples and the anomolous Hawaiian aerosol samples 

are both enriched in the rare earth elements and some of the heavy metals so that 

it appears possible to develop a unique chemical fingerprint for this dust and 

92 
-' o 

(J) 

o 

a: 

w 

"" 

5.0,..--,---,----,.----,.---, 

4.0 

3.0 

2.0 

1.0 

MLO 

UP SLOPE WINDS 

1979 

0-0 MARINE AEROSOL 

CRUSTAL DUST 

• 

• 

I . . .~ \" 

\. 

O~F~E~B~~M~AR~~~A~P~R--'--M-A~Y--L-~JU~N~ 

Figure 67.--Temporal variation of 

crustal dust and sea salt during upslope wind conditions at MLO when Asian 

dust impacts the area. 

-' o 

(J) 

a! 

w 

"" 

5.0r---r----.---,..---,.--~ 

4 .0 

3.0 

MLO 

DOWN SLOPE WINDS 

1979 

0-0 MARINE AEROSOL 

.-. CRUSTAL DUST 

FEB MAR APR 

\ 

\ 

\ . 

MAY 

• 

JUN 

Figure 68 . --Temporal variations of 

crustal dust and sea salt during downslope wind conditions at MLO when Asian 

dust impacts the area. 

identify its source by the chemical composition when samples of the source dust 

are analyzed. 

J. Miller of NOAA, who has calculated air mass trajectories during the time 

period, has shown that the air masses carrying the dust came from the west. The 

trajectories all point toward the northwest Pacific ocean and would indicate that 

the dust observed comes from the Asian mainland. These results agree very well 

with the characteristics observed by Duce et al. (1980) at Eniwetok, where they 

observed an increase in aluminum (dust) during the same period, and their air mass 

trajectories also point back toward the Asian mainland. The dust has been previously observed in Japan where it is generally yellowish or light brown (Kadowski, 

1979) . It would appear that during each spring season Asian desert dust is blown 

throughout a majority of the north Pacific basin. Further studies of the composition of dust samples from the Asian mainland and Hawaiian aerosols will provide 

more conclusive evidence for this long range transport. 

93 
5.4 Nuclear Fallout and High Vo lume Aerosol Collections 

Herbert W. Feely 

Environmental Measurements Laboratory 

U.S. Department of Energy, New York, NY 10014 

Precipitation samples, analyzed for 90Sr fallout from atmospheric tests of 

nuclear weapons, are collected monthly in plastic buckets at MLO and SMO. They 

are combined into quarterly composites and analyzed with samples from about 70 

other stations (see Feely et al., 1978). 

High volume filter samplers, whi ch sample air at about 1 m3 min- 1, are 

operated for EML at all four GMCC observatories. These are part of a network of 

about 20 samplers operated for EML, mainly in the Western Hemisphere. Monthly 

composites of the filter samples are analyzed routinely by gamma spectrometry for 

7Be, 95Zr, 137Cs, and 144Ce. Until mid-1976 they wer e a lso routinely analyzed 

radiochemically for 210Pb, 90Sr, and 239, 240pu. Results are reported quarterly. 

Table 30.--Quarterly mean con centration s of radionuclides in surface air filter 

samples co llect ed at GllCC observatories, 1978 to 1979 

1978 197 9 

1 2 3 4 1 2 3 4 

7BE (fCi m- 3 ) 

BRW 66 SO 26 48 84 SO 21 54 

MLO 194 197 149 175 144 220 181 161 

SMO 83 92 61 69 49 75 65 

SPO 118 141 114 192 232 89 116 140 

95Z r (fCi m- 3 ) 

BRW 1. 7 1.7 <0. 5 <0.5 <0.5 <0.5 <0 :5 <0.5 

11LO 1. 7 1.4 <0.5 <0 . 5 <0.5 <0 .5 <0. 5 <0.5 

SMO <0 . 5 <0. 5 <0.5 <0.5 <0 . 5 <0 . 5 <0.5 

SPO <0 .5 <0.5 <0.5 <0.5 <0.5 <0 .5 <0. 5 <0.5 

137Cs (fCi m- 3 ) 

BRW 1.7 2.1 0.5 0.4 0 . 7 0 . 5 <0 .1 0 . 2 

MLO 3.9 4. 7 1. 2 0.5 1.1 1.7 0.5 0.2 

SMO <0 .1 0.1 0 . 1 <0.1 <0. 1 <0.1 0.1 

SPO 0.1 0.2 0.1 0.2 0.3 0.2 0.1 0.1 

144Ce (fCi m- 3 ) 

BRW 13 . 6 13.7 3 . 8 1. 7 2.2 1.6 0 . 3 <0.4 

MLO 32.4 34.0 7.2 2.7 3.7 4.6 2 . 2 <0.5 

SMO <0.5 0.5 <0.5 0.4 <0.3 <0.2 <0.3 

SPO <0.5 <0.5 <0.5 <0. 5 <0.3 <0. 3 <0.3 <0.3 

94 
Table 30 summarizes quarterly mean concentrations of the various radionuclides 

measured in surface air filters for 1978 and 1979. The cosmic ray product, 7Be, 

is usually high in concentration at MLO throughout the year. This station appears 

to represent adequately the air of the upper troposphere. Samples from BRW and 

other Arctic sites show a summer minimum and winter maximum in 7Be concentration. 

7Be is produced predominantly in the upper troposphere and lower stratosphere, and 

reaches the surface layer of air preferentially at midlatitudes. Evidently it is 

transported into the Arctic from midlatitudes most rapidly during winter, at the 

time of formation of the Arctic haze layer. 

The artificial radionuclides from nuclear weapons tests currently measured in 

the filters are the fission products 95Zr, 137Cs, and 144Ce. At MLO high concentration of 95Zr were found throughout 1977, and significant concentrations of 

137Cs and 144Ce persisted through the first half of 1978 as a result of fallout 

from the 17 November 1976 Chinese nuclear test, which had a yield of 4 megatons. 

Lowe r concentrations of these radionuclides were found at BRW during this period, 

and negligible amounts of the radioactive debris from this Chinese test reached 

the stations in the Southern Hemisphere. Only low concentrations of fission 

products were found at any of the GMCC sites by the end of 1979. 

5.5 Attenuation of Solar Radiation by Atmospheric Particles at MLO, 1958-1978 

G. D. Robinson 

The Center for the Environment & Man, Inc. 

Hartford, CT 06120 

The MLO pyrheliometric record (discussed in Mendonca et al., 1978) was examined in terms of the total atmospheric attenuation of the direct solar beam to 

isolate the effect of suspended particles from other attenuations, specifically 

Rayleigh scattering, 02 and 0 3 absorption, and H20 absorption. First the attenuation was computed by known sources and subtracted from the observed attenuation. 

The record consists of monthly means of measurements on meteorologically quiet 

days, so that variation of surface pressure (the only unknown in the Rayleigh and 

02 terms) is very small. Trial computation showed that in these conditions at MLO 

the variance of the attenuation of the monthly mean averaged direct solar radiation by 0 3 could be neglected in comparison with the variance of that connected 

with particles and H20. The investigation then became a search for a method of 

separating the effects of these two major variable attenuators, based on the 

different relations between attenuation and solar zenith angle for the highly 

selective H2 0 absorption and the relatively grey attenuation by particles. 

The analysis was carried out on a set of tabulations prepared by the GMCC 

staff. The MLO pyrheliometric measurements were multiplied by the square of the 

radius vector and combined into six parameters, monthly means of which were 

tabulated. These parameters are 

where 

T.. and S ~ ., i = 2 to 4, j = i + 1, 1J 1J 

T . . 1J 

S~. = (1. + 1.)/2T . . , and 

1J 1 J 1J 

1. 1 = measured solar intensity at zenith angle S-1 i 

corrected to mean solar distance. 

95 
The datum examined by Mendonca et al. (1978) is ~ T . . /3, a conventionally i 1J 

specified transmissivity combining the effec t of molecular and particle scatt ering 

and gaseous and particle absorption. The principle of this method of reduction, 

from Ellis and Pueschel (1971), is 

where 

a~M. = ~I. = I T., 1 1 0 1 

M is an instrument reading, 

a is the applied instrument calibration factor, 

~ is the ratio of the true (but unknown) instrument 

calibration factor to a, 

I is the true (but unknown) value of the solar constant, o 

so that T . . = 1 ./1. = M./M. is independent of the unknowns ~ and 

1J J 1 J 1 

I as 

o 

they remain constant during 

depends on both I and~ . 

a measuring period, but S~ . = (I 12~), 1J 0 (T. 1 

o 

long as 

+ Tj)/Tij 

The original Ellis-Pueschel method further assumes that the transmissions may 

be approximated by Beer's law 

where 

so that 

T. _ exp (-Ki), 1 -

K is the zenith optical path from all attenuators, 

T .. _ T ::: exp ( - K) , 1J 

i T. _ (T) , and 

1 -

s~. = (I 12~) (T)i- 1 (1+T). 1J 0 

A third set of parameters was examined, defined by 

= [(T .. )i + (T . . )j]/[T . + T . ] . 1J 1J 1 J 

If the attenuation by particles alone follows Beer's law (a much less restrictive 

assumption than that of Ellis and Pueschel), the B~. depend only on ~ and the H2 0 

1J 

path, and are independent of t, the optical depth of the particles. 

A catalogue of the transmissions (I c . ) of a set of standard atmospheres of 

specified 03 and H2 0 content and specifiea optical depth caused by particles (t) 

was computed for the set of zenith angl es s-l i . From these computed intensities 

the sets of parameters 

96 
c c c T . . = 1./1., ~J J ~ 

SC . (Ic + c c 

= Ij)/T I ~J ~ ij 0' 

and 

c [(Tc)i-l c i

l 

c B .. - + (Tij ) /Sij ~J ~J 

= [(T ~ j + (Tc.)j lj(Tc + TCl = (Tch (Tc)j ~J ~J ~ J J ~ 

were formed. 

Details of the comparison process of the observed parameters with the computed catalogue and of interpolation procedures will be reported in a month-tomonth tabulation over the record period (see figs. 69 and 70). 

Esti ... ted randa!ll error 

-.. Eo- I +11- I -1- f - - .04 ... 

~ Probable ,y't~t1c error 

c 

.. 

N 

c· --11r- -1I~ .. .. .03 v 

- Thigh T low 

Ir" ~ 

.. 

.. .... 

-0 

"" 

r 

~ ~ 

.... .02 .. ." 1" 

-.. 

u 

-~ 

.... 

0 ~~ .01 .J 

r V;'W ~ w II 

r 

I 

1960 

I 

1965 i 

Date I 

Agung Awu,ete . 

Figure 69.--nonthly mean zenith optical path of particles at nLO. 

97 
·020 

.015 

• 010 

, 

. 

." .-

•••••• 1963-T979 

-- 1958-1962 

, 

" 

............ ... ..... ,.. . ...... 

Figure 70.--Annual variation of particle optical depth. 

5.6 Mauna Loa Solar Spectral Irradiance Program 

Glen E. Shaw 

Geophysical Institute, University of Alaska 

Fairbanks, AL 99701 

The University of Alaska has establihed a program at MLO to search for tiny 

fluctuations in the Sun's radiation near the time of maximum solar activity . The 

research is supported by the NSF's Office of Climate Dynamics, and its goal is 

determining solar spectral irradiance in 12 narrow (10-nm) wavelength passbands in 

the near ultraviolet and visible regions of the electromagnetic spectrum. On each 

clear day the extraterrestrial spectral solar irradiance is monitored to a precision of -0.1%, and the day-averaged measurements are transferred to an absolute 

electrical scale of units to an accuracy of 1% for later comparison with measurements carried out around the time of minimum solar activity. It has been suspected 

that although the so lar constant (the total solar radiation at all wavelengths) is 

apparently constant to a fraction of 1%, the spectral irradiance, especially at 

blue and near ultraviolet wavelengths, may be fluctuating in response to periodic 

changes in dynamical activity taking place beneath the Sun's photosphere. The 

changes in total solar radiation caused by fluctuating spectral irradiance at 

short wavelengths may be compensated by simultaneous slight increases or decreases 

in the radiation at the longer wavelength by a greenhouse effect mechanism . That 

is, the total area under the curve of so l ar spectral irradiance (the solar constant) 

tends to be stationary in time, although the shape of the spectral distribution of 

sunlight undergoes variations . Identifying spectral irradiance variations could 

improve understanding of Sun-Earth climatic coupling mechanisms. For example, the 

equilibrium vertical distribution and concentration of trace constituents in the 

Earth' s uppe r atmosphere (OH, 03 , etc.) may be modulated and force alterations in 

climate parameters through interactive feedback loops. 

98 
The solar spectral irradiance program began operation at MLO in February 

1980 . Data will be taken continually for at least 1 year. A by-product of the 

program will be a set of determinations of t he spectral atmospheric optical transmissivity above Mauna Loa that will represent benchmark data for comparison with 

similar measurements in the future, to see if global aerosol loading is slowly 

increasing. 

5.7 Ultraviolet Erythema Global Measuring Network 1979 

Da niel Berger 

Temple University 

Philadelphia, PA 19140 

The sunburn ultraviolet meter network has operated since Septemb er 1973. 

Data represent energy in the UV-B and can be related to sunburn, DNA damage, and 

other effects of ultraviol et light on biologic systems. At present 30 sta tions 

are in operation (see t able 31) . NOAA is now preparing a 5-yr s ummary of network 

dat a . Collected data are disseminated on request by NOAA, 8060 13th Street, 

Silver Spring, HD 20910. 

5.8 Ozone and Solar Radiometry 

Ronald J. Angione and Robert Roosen 

San Diego State University 

San Diego, CA 92 182 

Three instruments were brought to lLO in arch 1979 for intercomparison. The 

main instrume nt was a microprocessor controlled filt er wheel radiometer employing 

a temperature controlled (±O.l°C) photodiode detector and 11 narrow band (100 A 

FWHH) filters. The f ilters were selected to determine the amount of atmospheric 

dust, total ozone from the Chappuis band, and total precipitable water vapor from 

the 0.93 -~m band. We were parti cularly interested in comparing ozone amounts 

derived from the Chappuis band with those derived by the Dobson. 

The remaining two instruments were both absolute cavity radiometers: a 

Willson ACR and a Kendall Mark VI . Our main purpose in bringing t he absolute 

cavities to MLO was to intercompare them, taking advantage of the nearly ideal 

atmospheric conditions at ~lLO. 

During our 1-wk stay we were able to make measurements on 4 c lear days . The 

mean aerosol optical depth a t 0.5011 ~m for the 4 days was 0.030. The ozone 

values derived from the Chappuis band were on the average 17% l ower than the 

corresponding Dobson values. The caus e for this difference is being studied. 

We made 24 intercomparisons of the Willson and Kendall absolute cavities at 

a variety of different air masses on the 4 days. The cavities remained constant 

with respe ct to each other with a standard deviation of 0.1. The Willson yielded 

values consistently higher than the Kendall by 0.6%. 

99 

• 
Table 31.--Stations in sunburn ultraviolet meter network 

Stations 

Gainesville, Fla. 

Bismarck, N. Dak. 

Talla hassee, Fla. 

Oakland, Calif. 

Fort Worth, Tex. 

Minneapolis, Minn . 

De s Moines, Iowa 

Albuquerque, N. Mex. 

El Paso, Tex. 

fotauna Loa, Hawaii 

Philadelphia, Pa. 

Honeybrook, Pa. 

Detroit, Mich. 

Seattle, Wash. 

Salt Lake City, Utah 

New Orleans, La . 

Atlanta, Ga. 

Tucson, Ariz. 

Belsk, Poland 

Warsaw, Poland 

Aspendal e (Melbourne), Australia 

Brisbane, Australia 

Davos, Switzerland 

Hamburg, Germany 

Panama 

Point Barrow, Alaska 

Rockville, Md. 

Hamilton, New Zealand 

Basle, Switzerland 

100 

Period in continuous operation 

Aug 1973-pre sent 

Oct 1973-present 

Sep 1973 -present 

Oct 1973-pres ent 

Sep 1973-present 

Oct 197 3-pre sent 

Oct 19 73- pres ent 

Sep 1973-present 

Sep 1973-present 

Dec 1973-pre sent 

Sep 1973-present 

Nov 1974-present 

Sep 1977-present 

Sep 1977-present 

Oct 1977-present 

Sep 1977-present 

Oct 1977-present 

Jun 1975-present 

tlay 1975-present 

Jun 1975 -Sep 1976 

Jun 1974-present 

May 1974-present 

Oct 1974-present 

Feb 1976-present 

Nov 1978-present 

Oct 1978-present 

Sep 1978-present 

tlay 1980-present 

Mar 1980-present 
5.9 Satellite Determination of Ozone 

W. G. Planet 

National Environmental Satellite Service, NOAA 

and 

A. J. Miller 

National Weather Service 

Washington, D.C. 20233 

The National Environmental Satellite Service continues to receive total ozone 

records from 11 Dobson stations either operated directly by GMCC or associated 

with it. The data records begin in November 1978 and will continue through the 

operational lifetime of the TIROS-N series of operational environmental satellites 

into the late 1980's. 

The atmosphere sounder on TIROS-N has spectral channels whose measured 

radiances are correlated with the total ozone amount. A mu ltichannel regression 

scheme has been established whereby total ozone on a global scale can be deduced 

from the satellite measurements. To establish and upgrade the individual regression coefficients, coincident Dobson measurements and satellite observations are 

required. The regression coefficients are generated and implemented in the 

TIROS-N data processing system. Regression coefficients are latitudinally stratified and changed seasonally. The ozone amounts derived from the satellite measurements continue to be evaluated by comparisons with a selected subset of Dobson 

measurements for determining the accuracy of our retrieval process. 

The same Dobson data set is also being used for the verification of ozone 

values determined by the Nimbus-7 SBUV/TOMS system . These efforts are under way 

in the Analysis and Information Branch, National Meteorological Center, Asheville, 

N.C. 

Preliminary results of these efforts were presented in the fall 1979 AGU 

meeting and at the XVII General Assembly of IUGG, 1979. 

5.10 Daily Sunspot Count, American Association of Variable Star Observers 

W. R. Winkler 

National Geophysical and Solar-Terrestrial Data Center, EDIS 

Boulder, CO 80303 

When weather and official duties permit, daily sunspot number is observed and 

reported monthly to the American Association of Variable Star Observers, Cambridge, 

Mass. Each daily observation is combined with others to determin RA, the "American 

sunspot number." This index closely follows Rz, the "Zurich sunspot: number." 

Both are published by the National Geophysical and Solar-Terrestrial Data Center 

in Solar-Geophysical Data--Part I, which appears monthly . Sunspot number, the 

only long term index of solar activity, dates from about 1750 . 

Visual counts of sunspots are made using a filtered 4-in reflecting telescope 

located in the fifth floor dome of RB-3 in Boulder, Colo. Figure 71 shows the 

form used by observers to report their data. 

101 
AAVSO - SOLAR DIVISION 

!)AI ~~~.~ , .... '.!: _~;,;, ",,~": ..... . _~!;, .. , ~.; _'~~~. _~ •. J(:;. 3

Ji

FIS ::~~:aor /8'/Po""lly~;' 

10 

" " 13 

" " 

IJ " 

11 

11 

" " 

-S 14 '-<1. 

S Iq ":; ''f 

5" ~O 70 

&-J :ZIJ S 24 74 

, '!r-I /~o '7 ;;i.'i G8' 

r-1 I~' S '(. I f. {,., ~~-( 18'( 4 3 .".3 

G-- 1 1 ,,~, '" "7 ";'7 

(~-J 11W q 14-7 1/3 '7 

1/'-1 'QO, I- ,I 

16--.3 :;!33 If 144- 11S"4 

1(,-( .. :;.q. 13 .<>, I/ll~ 

.1 

'/ 

,*" 

.3 I /~ IS 

I I S 

l?' S 

..; ..... 14-

4- S 1/5 3a 

<:" t I q 42 

,* 

~ 

11 -/ 1, .. 1/, 1;}' ;44 1(,1/. 5 '7 l!i ~'j 

11 

14 

n Cr · ISO 

~:? := ;~i? ili ']:~r::i"=!:~i~~r:~ :''':'':'':''''':';''''':~: ;~ ~...o': ::, :. :t.." .. ~~rr~ .. " ............... ,._. 

~~~~j~~:~~~~·*'C<::::r'm' 

_ ... . ., .... " .. ......... , ............ " , .. ::: :i~~:.~ W.T- '·:';'; ~ :f; p:~' .. "!.'=. 

Figure 71.--Typical sunspot report form. 

102 
5 . 11 Precipitation Chemist ry at Samoa and Ma una Loa 

Donald C. Bogen, Stuart J. Nagourney , and Cami lle C. Torqua t o 

Environmenta l Me a surements Labor atory 

U. S. Depa rtment of Ene rgy , New York, NY 10014 

Monthly samples of wet, dry, and tota l deposition are coll ected at SMO and 

MLO. The samples are sent t o the Envi r onmental Meas urements Laboratory CEML) for 

physical and chemical measurements . 

The average monthly deposition value s and r ange of results at SMO and ~lLO for 

April 1978 to March 1979 are pres ented in t ables 32 and 33. 

Table 32 .--Chemi ca l ana l yses of total, wet , and dry deposition at SMO, April 1978 

t hrough Ma rch 1979 

Total Co llec t or Wet collector Dr:t: col l ector 

Mean Range ean Range Mean Range 

Vo lume (R.) 7.88 0-1 4.0 10 . 0 1.96-14.4 

pH 6 . 01 5 . 49 - 6 . 48 5.81 5.45-6.26 

Conduc tivity 

S em - ') 

69 . 4 19-115 25.9 9.6-63.5 

CI 112 63- 191 52 20-89 69 38-98 

(mg mo ') 

SO.-2 20 10 - 31 9.9 3.7-16 10 . 9 6 . 6-15 - (mg mo ') 

N0 3 3 .8 ND'·'- 41 0 . 02 ND·:'-0.28 0.01 ND" - 0.08 

(mg mo-' ) 

+ Na 70 38- 120 33 18-120 42 23-61 

(mg mo-' ) 

+ Mg 2 8.9 4.7- 16 4.0 1.6-7. 3 5.1 2.7-7.7 

(mg mo-' ) 

Ca +2 3.2 2.0-5.3 1.6 0 . 8-3 . 0 1.8 1.1 - 2.6 

(mg mo-') 

+ 

K 3. I 1.7-5 . 5 1.4 0.6-2.5 2 . 0 1.0- 2.8 

(mg mo-') 

Tot.al cations I. 12 ± 0 .06 I. 15 ± 0 . 08 1.11 ± 0.06 

Total anions 

* NO-not detectabl e 

103 
Table 33. -- Chemica 1 

t hrough Nar ch 1979 

Vo lume (,0 

pH 

Condu c t!yity 

(fJS em 1 ) 

CI 

(rng rna 1 ) 

SO , - 2 

(rn g rno - ' ) 

N03 (rng mo - 1 ) 

Na + 

- (rn g rn a 1 ) 

+ Ng 2 - (rn g rna 1 ) 

Ca+ 2 

(rn g mo- 1 ) 

K+ - (rn g rna 1 ) 

Tota l ca t ions 

To t al anions 

-,,'( 

ND-not detec table 

analys es of t o t a l, we t, and dry de positi on a t NLO, 

To t a l Colle cto r Wet co llec t or 

Mean Range Mea n Range 

2.44 0-11 .7 3 . 55 0-9. 8 

5 .1 3 4. 77 - 5 .56 5 .48 5 .01-5 . 85 

5. 74 2 .5-8 .8 3 .68 2 . 2- 6 . 2 

0. 21 0.02-0 .58 0.19 0 . 03-0 . 43 

1. 32 0 . 15- 3 . 99 0 .80 0.03- 2 . 09 

0. 09 ND "' -O . 48 0. 11 ND" - 0 .56 

0. 39 0 . 04- 2 . 5 1 0 .20 0. 02 - 0 . 55 

0.07 0.01-0. 22 0.07 ND'·' -0 .1 9 

0 . 09 ND" - 0.35 0.08 ND" - 0. 23 

0 . 02 ND" -0 . 05 0 . 02 ND* - 0 . 09 

0 .93 ± 0 . 16 1. 02 ± 0 . 32 

5.12 Drifting Snow at Barrow 

G. Wendle r 

Geophysical Institute, University of Alaska 

Fairbanks, AL 99701 

April 1978 

Dr;r col l ecto r 

~f ea n Ra nge 

0.0 7 0 . 02 -0 .28 

0 . 47 0.09- 0.95 

0 . 04 ND" - 0.2 1 

0 . 13 0 . 04 - 0. 32 

0. 02 0 . 01- 0 .04 

0 . 05 0.01-0.06 

0.0 1 ND* -O.03 

0 . 98 ± 0. 17 

On the Antarctic continent snow is redistributed, blown off, or evaporated. 

It is influential for all practical operations, since zero visibility i s frequently 

experienced during periods of blowing snow. We are studying the katabatic wind in 

the French sector of Antarctica, an area where high winds are f r equent. A maximum 

windspeed of 196 m h- 1 was measured at Dumont d'Urville , but the whole austra l 

wi nter is windy. 

Schmidt developed an instrument that measures the size distr ibution of particles as we ll as frequency of blowing snow particles. We obtained a sensor from 

Schmidt but built our own electronics along lines des cribed by Schmidt. Before 

104 
building three more instruments and installing them in Antarctica, we are testing 

one sensor including electronics at BRW. In contrast to Fairbanks where the winds 

are light in winter, BRW is more exposed and drifting snow is a common occurrence. 

Testing was sucessfully completed during spring 1980. 

5.13 Recalibration of the Pollak Counter 

at the 680-mb Level 

A.W. Hogan 

State University of New York at Albany 

Albany, NY 12222 

The Pollak-Nolan photoelectric nucleus counter has been used as an aerosol 

detector by the GMCC program since its inception. The actual instruments in use 

are replicas of the last Dublin version, using a 2.5-cm unglazed ceramic fog tube 

and convergent light beam, constructed from Pollak's drawings by R. Gussman. The 

intrinsic calibration for this instrument has been used to convert observed values 

of light transmission through the fog tube to initial aerosol concentration. 

The intrinsic calibration was established at sea level; Emmanuel and Squires 

(1969) repeated the calibration of Pollak's counter near the 850-mb level and 

concluded that the sea level calibration was s uffi ciently accurate for fie ld 

studies. When the Pollak counter was installed at Mauna Loa, A.W. Hogan compared 

the instrument with an Aitken counter and found their measurements to generally 

agree over the range of concentrations expected to be observed. Since both Mauna 

Loa and South Pole have average st ati on pressures of around 700 mb, a comparison 

of the Pollak with the photo r ecording Aitken counter of Winters, Barnard, and 

Hogan (1977) was conducted a t Mauna Loa to confirm the numerous data collected at 

these stations. 

5.13.1 Preliminary Ca lculations 

The Pollak photoelectric nucleus detects particles smaller than a wavelength 

of light by Aitken's method of forcing them to grow into visible drops in a supersaturated environment. The calibration is based on the amount of change in light 

transmission caused by the formation of these. drops on the initial particles; if 

more or less water vapor is made available to the growing particles, then in 

theory, the amoun t of light transmission at a given concentration may be altered, 

invalidating the ca libration. Sensitivity of an Aitken counter does not depend on 

the size of the drops formed, as long as the drop grows to visible size; it can 

then be used as a refe rence instrument at the higher altitude. 

The saturation in the Pollak counter is produced by raising the pressure in 

the aerosol filled fog tube with filtered air, allowing the sample to come into 

humidity equilibrium with the moist walls, and then expanding the air by venting 

the chamber to ambient pressure. The saturation produced is then ca lculable from 

adiabatic considerations: 

T = T (PIP) .286 

F 0 0 

At sea level an expansion of 160 mm Hg is used; 

P + tu' 

-=0---;:,-_ = 

P 

o 

760 + 160 

760 = 1.21 . 

105 
The same expansion ratio can be achieved at Mauna Loa and South Pole by adjusting 

t he overpressure accordingly : 

P o +LlP 

P 

o 

= 

511 + LlP 

511 = 1.21, 6P~105 mm Hg. 

If the amb ient temp eratures is assumed to be 293K (20°C) at all stations, the 

adiabatic temperature change can be calculated from the pressure ratio, 15.6°C . 

The saturation can be calculated from values given in the Smithsonian Tables, or 

an adiabatic diagram: 

Sa tura tion 

Temp. Pressure mixing ratio Supersaturation 

293K 10 13 mb 14.6 g kg-' 2.81 

277.4K 10 13 mb 5.2 g kg -, 

293K 681 mb 21.4 g kg-' 2.78 

277.7K 681 mb 7.7 g kg-' 

At sea level, this would liber~te 9 . 4 g kg-' of water condensation, and at Mauna 

Loa it would release 13 .7 g kg '. When this is converted to volume mixing ra t io, 

we find 11.99 g m- 3 available at sea level; at Mauna Loa 12.24 g m- 3 are availabl e. 

The ratio of the cube roots of these values indicates that the drops may be 0.7% 

larger at Mauna Loa, which should not greatly influence the calibration . 

5. 13.2 Re s ults of Experiments 

The theore tri ca l considerations above indicate t hat no real discrepancy 

should exist between a sea level calibration of the Poll ak counter and one at 

approximately 700 mb. The experimenta l results (fig . 72) indicate that this is 

true, since there is little or no systematic difference between t he number of 

particles meas ured by the Aitken and Pollak techniques. Ambient aerosol was used 

for these comp arisons, and the two instruments were operated in close time and 

space proximity. 

Although there is little systematic difference through the ca libration 

range, there is extreme variation when individual readings are compared. For 

example, 26 individual determinations of aerosol concentration were made, over a 

period of 5 days, when the Pollak counter i ndicated transmission of 93.5 to 94.5, 

a tYRical Mauna Loa value. The mean of these was 93 .9, which corresponds to 

156 /cm3 ; the extreme values of 93.5 and 94.5 correspond to 170 n/ cm3 and 

137 n/ cm3 , respectively. The simultaneo us observations of concentration made with 

the Aitken counter ha ve a mean value of 164 n/ cm3 , which is in good agreementn but 

the individual values determined by the Ai tken counter ranged f rom 42 t o 301 /cm3 . 

This variation is apparently random error, since the sensitive volume of the 

Pollak counter contains 7,300 particles at this concentration , whereas the Aitken 

counter contains only 21 as a mean value. Since t he particles are 2 mm apart at 

this concentration, a sensitive volume 1 mm thick would be subject to extreme 

concentration variation during instantaneous determinations. The six plotted 

points near this value in fig . 72 are the means of determinations during six 

106 
z 

0 

~ 

~ 

~ 

~ 

z 

w 

u 

z 

0 

u 

1000,----,--------,--------,,-------, 

MLO 680mb 

• 

0 

0 

0 

0 

0 

f 

0 0 

0 

85 90 95 

POLLAK R 

Figure 72.--Scale reading of Pollak 

replica PG13 at MLO (station pressure 

681 mb) and coincident concentration 

determinations made with a photographic 

Aitken counter. The plotted curve is 

the Metnieks Pollak 1960 calibration. 

Solid circles are means of 10 or more 

determinations at the same Pollak reading, open circles single values. 

periods. This wide range of Aitken va lues corresponding to a narrow range of 

Pollak values is a strong argument in favor of the Pollak as a prime instrument 

for obtaining c lima tological aerosol data. 

An experiment was conducted at Mauna Loa, during a period of very stable 

natural aerosol concentration, to determine the sensitivity change of the instrument at several expansion ratios. The results of this experiment (fig . 73) indicate that the extinction in the fog tube is a linear function of water made available by the expansion up to the established (1.21) Aitken expansion ratio. At 

greater expansions the response flattens, probably because the relative radius 

change in the drops formed is diminishing. There are no discontinuities in the 

curve, which might be expected if additional particles were activated at some 

supersaturation rather than the additional available water causing existing drops 

to become larger. The minimum overpressure used was IS mm Hg, which would produce 

a supersaturation of 1.20, sufficient to cause growth on 6 x 10- 7 cm radius particles. It would seem reasonable to conclude ·that the Mauna Loa aerosol on this day 

consisted of particles larger than this, which is in agreement with past work with 

diffusion batteries. 

5.13.3 Conclusion 

The Pollak 1962 intrinsic calibration of the photoelectric nucleus counter 

is valid for climatological aerosol determinations at 700- mb station pressure. 

Slightly exceeding the optimum (Aitken) expansion at altitudes above sea 

level has little influence on the value of concentration observed. Failure to 

achieve the Aitken saturation results in severe loss of sensitivity. 

Acknowledgment 

This work was supported by NOAA/ERL/ARL/GMCC under contract NA79RAD00023. 

107 
z 

o 

IU 

Z 

I10 

o 

.1 

0/ - 0 

Figure 73.-- Variation in extinc tion 

::: 5 I (100% reading) observed with the Pollak 

counter when va ring the initial overpress ure. The extinction appears to be a 

linear function of the amount of water 

made avai l able for condensa tion. Increasing the overpressure causes l ess 

change in sensiti vity per unit pressure 

than de creasing the overpressure. The 

smallest overpressure used (15 mm Hg) 

produced a s upersaturation of 1 .2, whi ch 

should cause growth of particles larger 

than 6 x 10- 7 cm radius. 

o 

0 

"' S2 

• " • I • • ~ 

I I I I I I j j I 

OVERPRESSURE. MM HG 

°0~~~~~5~~~~~0~~~~-1~5~~--' 

CONDENSABLE WATER GM/KG 

5 . 14 Measurement of 502 and TSP at Mauna Loa Observato ry 

Richard Sasaki, Mavis Kadooka, and Wilfred Ching 

Department of Health , State of Hawaii 

Honolulu, Hawaii 96801 

The cooperative program between the Department of Hea lth, State of Hawaii, 

and NOAA is nearing completion of its third year of data collection. All raw data 

are being checked for accuracy, along with all required quality assurance data to 

ensure final data validity. Final computation and assessment have been delayed by 

l ate receipt of computer progr ams and equipment . Evaluation and assessment and 

all data will not be available until later this year. 

108 
6. INTERNATIONAL ACTIVITIES 

Under the U.S. A.-U .S.S.R . Agreement on Cooper~tion in the Field of Environmental Protection, Working Group VIII, Soviet scientist Alexander Shashkov visited 

the NOAA Air Resources Laboratory, Boulder, Colo., from 9-28 October 1979, to 

study techniques and apparatus used in the NOAA /ERL/ARL Geophysical Monitoring for 

Climatic Change (GMCC) program for measuring carbon dioxide. During the visit, 

Dr. Shashkov studied procedures and equipment used in CO2 flask sampling; practiced 

collecting CO 2 flask samples a t Niwot Ridge, Colo.; studied instrumentation and 

methods employed in analysis of atmospheric CO2 using nondispersive i nfrared 

analyzers; and parti cipated in the analysis of t he air samples co llected at Niwot 

Ridge. Dr. Shashkov also had opportun ity to study details of construction of 

nondispersive infrared CO 2 analyzer apparatus for continuous CO 2 measurements, 

manual CO2 flask sample ana lysis instrumentation, and a newly developed semiautomatic apparatus used for analyzing CO2 flask air samples. 

While in Boulder, the Soviet scientist had an opportunity to become familiar 

with other GMCC programs concerning monitoring of atmospheric trace gases, including Freons, nitrous oxide, and ozone. He made a presentation at a GMCC seminar on 

techniques, instrumentation, and some results of the spectroscopi c method developed 

in the U. S. S.R. for measuring the average CO 2 mixing ratio in a vertical column of 

the atmosphere . Useful discussions were held concerning spectroscopi c instrument 

and nondispersive analyzer measurements of atmospheric CO2 and CO2 monitoring in 

general . 

In October, 1979, K. Hanson traveled to Tblisi, U.S.S.R., to participate in 

the fifth annual meeting of Working Group VIII under the U.S .-U .S.S.R. Agreement 

on Protection of the Environment. 

At the request of the World Meteorological Organization (Global Ozone Research 

and Monitoring Project) R. Grass participated in the Europian regional Dobson 

spectrophotometer intercomp arison held in Potsdam, German Democratic Republic, in 

June 1979. The primary reason for the intercomparison was to ensure the compatibility of ozone measurements with Dob son ozone spectrophotometers for research 

purposes by comparing them with the regional standard instrument, which had been 

ca librated by the world standard at Boulder, Colo., in August 1977. While at 

Potsdam the Czechoslovakia Dobson no. 74, Hungarian Dobson no. 110, and the 

Romanian Dobson no . 121 were modified with the U.S. solid state circuits. Optical 

alignments were made on the se three instruments as well as the French Dobson no. 

11 and the German Federal Republi c Dobson no. 44. Wedge calibrations we re performed on Dobson no. 's 44, 74, 84, and 110. A training session was also conducted 

to teach the participants the procedures for performing certain tests and the 

techniques for making optical adjustments on the instruments. 

In September 1979, B. Mendonca traveled to Chile, Peru, Ecuador, and Brazil 

to aid in initiating CO 2 monitoring sites at Easter Island, Chile; Cosmos , Peru; 

and Galapagos Islands, Ecuador. Initial government contacts were made. The scope 

of the CO 2 measurement program was explained as well as t he techniques of fla s k 

s ampling at remote sites. 

109 
B. Mendonca made a brief visit to Brazil to follow up on the solar radiation 

calibration facility that was started in 1979 at the national meteorological 

center in Bras11ia. The National Meteorologica l Institute there has initiated a 

national solar radiation monitoring network with the headquarters at the Solar 

Radiation Calibration Center in Bras11ia. All data are forwarded to the center 

for processing and evaluation. On the invitation of the University of Belem in 

Para, Brazil, B. Mendonca conducted a seminar on the GMCC program. Informal talks 

were held with the university staff to explore possible cooperative programs 

between the GMCC program and the University of Belem. Interest was expressed in 

acid pre cipitation and carbon dioxide measurements. 

110 
7. 1979 PUBLICATIONS AND PRESENTATIONS BY GMCC STAFF 

Bodhaine, B. A. Ae rosol monitoring at Barrow, Mauna Loa, American Samoa, and the 

South Pole: instrumentation and results. Proceedings, WHO Technical Conference on Regional and Global Observations of Atmospheric Pollution Relative 

to Clima te, 20-24 August 1979, Boulder, Colo. 

Bodhaine, B. A. A modified General Electric condensation nuclei counter and its 

operation at baseline sites. Presented at 53rd Colloid and Surface Science 

Symposium, 11-13 June 1979, Rolla, Mo. 

Bodhaine, B. A. GMCC 

March 8-9, 1979. 

Aerosol Chemistry Workshop summary and recommendations, 

Bull. Am . Meteorol. Soc. 60(11):1337-1339. 

Bodhaine , B. A. Measurement of the Rayleigh scattering properties of some gases 

with a nephelometer. ~ ~ 18:121-125. 

Bodhaine, B. A. Nephelometer l i ght scattering me asurements at baseline monitoring 

sites . Presented at 53rd Colloid and Surface Science Symposium, 11-13 June 

1979, Rol l a, Mo. 

Cram, R. S., and H. R. Tatum. 

Hawai i, Jan.-Feb. 1979. 

Record torrentia l rainstorms on the island of 

Mon. Weather Rev. 107(12):1653-1662. 

Dave , J. V., J. J. DeLuisi, and C. L. tlateer . Results of a comprehensive theoreti ca l examination of the optical effects of aerosols on the Umkehr measurement. 

Proceedings, ~10 Technical Conference on Regional and Global Observations of 

Atmospheric Pollution Relative to Climate, 20-24 August 1979, Boulder, Colo. 

DeLuisi, J . J. Shortened version of the Umkehr method for observing the vertical 

distribution of ozone . ~ ~ 18:3190. 

DeLuisi , J. J. Umkehr vertica l ozone profile errors caused by the presence of 

stratospheric aerosols. ~ Geophys. Res. 84(C4):1766-1770. 

DeLuisi, J. J., K. J. Hanson, and B. G. tlendonca. Estimation of changes in the 

albedo and relative temperature due to stratospheric aerosols from Agung and 

subsequent volcani c activity. Proceedings, ~10 Technical Conference on 

Regional .and Global Observations of Atmo spheric Pollution Relative to Climate, 

20-24 August 1979, Boulder , Colo. 

DeLuisi, J. J ., C. L. Mateer, and D. F. Heath. Comparison of seasonal variations 

of upper stratospheric ozone concentrations revealed by Umkehr and Nimbus 4 

BUV observations. ~ Geophys. Res. 84(C7):3728-3732. 

Dutton, E. G., W. D. Komhyr, and T. M. Thompson. Global baseline concentrations 

of selected fluorocarbons and nitrous oxide. Proceedings, WHO Technical 

Conference on Regional and Global Observations of Atmospheric Pollution 

Relative to Climate, 20-24 August 1979, Boulder, Colo. 

Fegley, R. W. Practical comments on the Lidar monitoring of stratospheric and 

t ropospheric aerosols. Proceedings, WHO Technical Conference on Regional and 

Global Observations of Atmospheric Pollution Relative to Climate, 20-24 

August 1979, Boulder, Colo. 

111 
Hans on, K. J. Book reviews: Carbon Dioxide, Climate and Society, J. Williams 

(ed.), Pergamon, New York, N.Y., 1978. Clim. Change 2(2):194- 195. 

Hanson, K. J ., J. T. Peterson, B. G. ~Iendonca, and W. D. Komhyr ., Some examples of 

a tmospheric dynamical effects on atmospheric trace constituent s . Proceedings, 

4th Annual Climate Diagnos tics Workshop, 16-18 October 1979, di son, Wis., 

Inst. for Environ. Studies, Nadison, Wis., 246-265. 

Harding, D. , and J. N. ~liller. Studies of acid rain on the big isl and . Proceedings, Second Conference on Natural SCiences, 217-219. 

Harris , J. N., J. R. Jordan, and G. A. Herbert. Automation of GHCC's CO 2 Labora -

t ory operations using microprocessors. Proceedings, WHO Technical Conference 

on Regional and Global Observations of Atmospheric Pollution Rela tive to 

Climate, 20-24 August 1979, Boulder, Colo . 

Herbert, G. A., J. H. Harris, N. S. Johnson, and J. R. Jordan. Data acquisition 

and processing in mICC. Proceedings, WNO Techni ca l Conference on Regional 

and Global Observations of Atmospheric Pollution Relative to Climate, 20-24 

August 1979, Boulder, Colo. 

Hoyt, D. V. Atmospheric transmission from the Smithsonian Astrophysical Observatory pyrheliometric measurements from 1923 to 1957. J. Geophys. Res. 

84(C8):5018-5028. 

Hoyt, D. V. Pyrheliometric and circumsolar sky radiation measurements by the 

Smithsonian Astrophysical Observatory from 19 23 to 1954. Tellus 

31(3):217-229. 

Hoyt, D. V. Theoretical calculations of the true solar noon atmospheric transmission. In SOLNET, vol. 2 (TD-9724), Dept. of Energy, Ashevill e, N.C., 

119- 163. 

Hoyt, D. V. Variations in sunspot structure and climat e. Clim. Change 2 :79-9 2. 

Hoyt, D. V. Variations in the solar constant caused by changes in the active 

featu res on the Sun. In Solar-Terrestrial Influences on Weather and Climate, 

B. H. HcCormac and T. A. Se l iga (eds.), Reidel, Dordrecht, Holl 65-68. 

Komhyr, W. D. An aerosol and gas sampling apparatus for observatory use. Pro ceedings, ~IO Technical Conference on Regional and Global Observations of Atmospheri c Pollution Re l ative to Climate, 20-24 August 1979, Boulder, Colo. 

Komhyr, W. D., and T. B. Harris. NOAA CO 2 -in-air ca libration gas st andards. 

Pro ceedings, ~IO Technical Conference on Regional and Global Observa tions of 

Atmospheric Pollution Relative to Climate, 20-24 August 19 79, Boulder, Colo. 

Komhyr, W. D., W. R. Taylor, and T. B. Harris. A semi -automatic flask sample CO 2 

analyzer. Proceedings, WHO Technical Conference on Regional and Global 

Observations of Atmospheric Pollution Relative to Clima t e, 20-24 August 1979, 

Boulder, Colo. 
Mateer, C. L., J. J. DeLuisi, and C. C. Porco. On the development of the short 

Umkehr method for estimating the vertical distribution of ozone. Proceedings, 

WHO Technical Conference on Regional and Global Observations of Atmospheric 

Pollut ion Relative to Climate , 20-24 August 1979, Boulder Colo . 

Mendonca , B. G. (ed.). 

mary report 1978. 

Geophysical Monitoring for Climatic Change--No. 7. 

NOAA/ERL, 131 pp. 

SumMendonca, B. G., J. J. DeLuisi, K. J. Hanson, and J. T. Peterson . Signatures in 

atmospheric transmission variations at Mauna Loa Observatory, Hawaii. Proceedings, WMO Te chni ca l Conference on Regional and Global Observations of 

Atmospheric Po llution Relative to Climate, 20-24 August 1979, Boulder, Colo. 

Miller, J. M. The monitoring of acid rain. Proceedings, American So ciety of 

Civil Engineers meeting, Boston, Mass., 95-103. 

Miller , J. M. , and A. Yoshinaga. The acidity of Hawaiian precipitation. Presented at Committee on Atmospheric Chemistry and Global Pollution Symposium 

on Budget and Cycles of Trace Gases and Aerosols in the Atmosphere, Boulder, 

Colo. 

Miller, J. M., H. L. Volchok, D. C. Bogen, H. W. Feely, and R. J. Thompson. 

Evaluation of the U.S . baseline and regional precipitation chemistry program. 

Proceedings, WHO Technical Conference on Regional and Global Observation of 

Atmospheric Pollution Re lative to Climate , 20 - 24 August 1979, Boulder, Colo. 

Miller, J. M. The acidity of Hawaiian precipitation as evidence of long-range 

transport of pollutants. Proceedings, WHO Symposium on Long-Range Transport 

of Pollutants and Its Relation to General Circulation Including Stratospheric/ 

Tropospheric Exchange Processes , 1-5 October 1979, Sofia, Bulgaria. 

Miller, J. M. National Atmospheric Deposition Program: Analysis of data from the 

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Nimira, J. K., and J. J. DeLuisi. On the validity of the aerosol correction 

method s used i n the Dobson ozone measurements. Proceedings, WHO Technical 

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Relative to Climate, 20-24 August 1979, Boulder, Colo. 

Oltmans, S. J. 

Te chni ca l 

Pollution 

Near surface ozone meas urements in clean air. Proceedings, WHO 

Conferenc e on Regional and Global Observations of Atmospheric 

Relative to Climate, 20-24 August 1979, Boulder, Colo. 

Osborn, J. C., Jr. Geophysical Monitoring for Climatic Change (GMCC) 

Pole, 1978. Antarct. ~ ~ ~, annual rev. issue, fall 1979. 

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Peterson, J. T., W. D. Komhyr, T. B. Harris, T. E. DeFoor, and L. S. Waterman. 

On the within-year variability of ambient CO 2 mea surements at Barrow, Alaska. 

Proceedings, WHO Technical Conference on Regional and Global Observations of 

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118 
9 . G~lCC STAFF 

Director's Office 

*Kirby J. Hanson, Director 

*Bernard G. ~lendonca, Deputy Director 

Helen Cook, Secretary 

Gail M. Phillips, Secretary 

""Dale A. Gillette, ClRES 

John E. Hay, ClRES 

Bill Hiscox, Lt. (jg) NOAA Corps 

Jerome K. Nimira, ClRES 

,"John Osborn, Lt. NOAA Corps 

Graeme I. Pearman, ClRES 

Constance Shilvock, Jr . Fellow 

ACquisition and Data ~lanagement Group 

*Gary A. Herbert, Chief 

Connie Carla, Secretary 

*Joyce ~L Harris, Computer Programmer 

Lee Johnson, Computer Programmer 

Milton S. Johnson, Electronic Technician 

James Jordan, Electronic Engineer 

Steven Waas, Jr. Fellow 

Monitoring Trace Gases Group 

*Walter D. Komhyr, Chief 

Connie Carla, Secretary 

Patricia Angel, Clerk Typist 

"Robert D. Grass, Physicist 

*Thomas B. Harris, Meteorological Technician 

,"Samuel Oltmans, Physicist 

Frank Polacek III, Meteorological Technician 

*Lee Waterman, Chemist 

"Ellsworth Dutton, ClRES 

Robert Evans, ClRES 

Kent Leonard, ClRES 

""William Taylor, ClRES 

Aerosols and Radiation onitoring Gro up 

"'John J. DeLuisi, Chief 

Gail Phillips, Secretary 

Bonnie Hill, Secretary 

*Barry A. Bodhaine, Meteorologist 

Richard Cram, Meteorologist 

*Ronald W. Fegley, Physicist 

119 
Analysis and Interpretation Group 

*James T. Peterson, Chief 

Gail Phillips, Secretary 

Bonnie Hill, Secretary 

Douglas V. Hoyt, Physicist 

Cheryl Reynolds, Jr. Fellow 

Thomas Stoffel, CIRES 

Thayne Thompson, Physicist 

Mauna Loa Observatory 

1'Kinse ll L. Coulson, Director 

Judith B. Pereira, Secretary 

*John F. S. Chin, Physicist 

*Howard Ellis, Physicist 

Mamoru Shibata, Electronic Technician 

*Alan M. Yoshinaga, Analytica l Chemist 

Barrow Observatory 

*Thomas DeFoor, Lt . NOAA Corps, Station Chief 

*Dave Smith, Physical Scientist 

Bradley C. Halter, Electronic Technician 

Robert Hanby, Electronic Technician 

Samoa Observatory 

'~Donald W. Nelson, Station Chie f 

Roger A. C. Wi lliams, Electronic Technician 

South Pole Observatory 

'''John Bortnia k , Lt. (j g) NOAA Corps, Station Chief 

Charles Smythe, Electronic Technician 

1'Contributors to Summary Report 

tl: u .s. GOVERNMENT PRINTING OFPICE HaO - 1 77- 002/1236 Reg. 8 

120