Geophysical Monitoring 

for Climatic Change 

No.7 

Su arl Report 1978 

U.S.OEPARTME.T 

OF COMMERCE 

~ NATIONAL 

OCEA.IC A.O 

ATMOSPHERIC 

AOMI.ISTRATIO. 

E.VIRO.ME.TAL 

RESEARCH 

LABORATORIES 

. l 

• 
Geophysical Monitoring 

for Climatic Change 

No. 7 

Summary Report 1978 

Bernard G. Mendonca, Ed itor 

December 1979 

Boulder, Colorado 

US. DEPARTMENT OF COMMERCE 

Philip M. Klutznick, Secretary 

Nationa I Ocean ic and Atmospheric Adm in istration 

Richard A. Frank, Administrator 

Environmenta l Research Laboratories 

Wilmot Hess, Director 
NOTICE 

Mention of a co~nercial 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 such products is not 

authorized. 

ii 
CONTENTS 

FOREWORD 

ACRONYMS AND ABBREVIATIONS 

1. 

2. 

3 . 

4. 

5. 

SUMMARY 

OBSERVATORY FACILITIES 

2.1 

2.2 

2.3 

2.4 

Mauna Loa, Hawaii 

Point Barrow, Alaska 

Samoa 

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 

Surface Ozone 

Stratospheric Water Vapor 

Halocarbons and N2 0 

Stratospheric Aerosols 

Surface Aerosols 

Solar Radiation Measurements 

Meteorological Measurements 

Precipitation Chemistry 

Rain Chemistry at Kilauea Summit 

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 

Short Umkehr Method 

Robinson-Berger Meter Response 

Umkehr Vertical Ozone Profile Errors 

Confidence Interval for CO 2 Flask Sampling 

Isotopes of Carbon 

Nephelometer Calibration Studies 

Urban-Rural Solar Radiation at St. Louis 

U.S.A.-U.S.S .R. Atmospheric Transparency Measurements 

Mt. Kenya Site Survey Evaluation 

Trends in Atmospheric Transmission at Mauna Loa 

Smithsonian Radiation Data Evaluation 

Solar Variability and Climate 

Trends in U.S. Atmospheric Transmission 

COOPERATIVE PROGRAMS 

5.1 

5.2 

5.3 

5.4 

5.5 

South Pole Aerosol Climatology - SUNYA 

South Pole Aerosol Chemistry - Univ . of Md. 

Particle Analysis of Antarctic Aerosols - APCLjNOAA 

Monitoring of Large Atmo spheric Particles at South Pole -

Lab. de Glacio. du CNRS 

Chemical and Optical Properties of Barrow Aerosol - URI 

iii 

Page 

v 

vi 

1 

4 

4 

8 

10 

13 

20 

20 

23 

27 

33 

35 

39 

42 

49 

53 

60 

63 

67 

71 

71 

73 

75 

76 

78 

80 

80 

81 

82 

85 

87 

88 

88 

89 

89 

93 

95 

96 

97 
6 . 

7. 

8 . 

9 . 

5.6 

5.7 

5.8 

5.9 

5.10 

5.11 

5.12 

5.13 

5.14 

5.15 

5.16 

5.17 

5.18 

5.19 

5 . 20 

5 . 21 

5.22 

5.23 

5.24 

5.25 

5.26 

5 .2 7 

Aerosol at Barrow - CSIRO 

Ice Nucleus Measurements at Barrow - Univ. of Alaska 

Multiwavelength Turbidity at Mauna Loa - Univ. of Alaska 

Pyrheliometer Measurements at Mauna Loa -

Ctr. Environ. and Man 

UV Erythema Global Measuring Network - Temple Univ. 

Satellite-Based Estimates of Solar Radiation for GATE - ClRES 

Surface Solar Radiation Fluxes for Africa - ClRES 

Monitoring Spectral Quality of Solar Radiation -

Smithsonian Inst. 

Nuclear Fallout and Aerosol Collections - DOE 

Measurement of S02 and TSP at Mauna Loa -

Dept. of Health, Hawaii 

Precipitation Chemistry at Samoa and Mauna Loa - DOE 

Precipitation Chemistry at Mauna Loa - EPA 

Barrow Precipitation Data - USDA 

Boron in Marine Atmosphere - URI 

Atmospheric Carbon Dioxide Concentration - CSIRO 

Carbon Monoxide Monitoring - Max-Planck Inst. 

Stratospheric Nitrogen Dioxide - AL/NOAA 

Total Ozone Measurements and TIROS-N - NESS/NOAA 

Barrow Magnetic Observatory - U.S. Geolog. Surv. 

South Pole Riometer - Univ. of Calif., San Diego 

Antarctic Tritium - Univ. of Miami 

Atmospheric Electric Measurements at Mauna Loa -

Niagara Univ. 

INTERNATIONAL ACTIVITIES 

PUBLICATIONS AND PRESENTATIONS 

REFERENCES 

GMCC STAFF 

iv 

100 

101 

102 

103 

105 

106 

107 

109 

111 

112 

113 

114 

116 

117 

117 

118 

119 

119 

119 

120 

121 

122 

123 

124 

126 

130 
FOREWORD 

In this seventh annua l report the NOAA Geophysical Monitoring for Climatic 

Change (GMCC) program demonstrates that it is coming of age. In past years, 

this program has primarily collected data. Now that the data have accumulated, 

they ca n be analyzed, leading to valuable geophysical interpretations. 

The NOAA program documented in these pages has captured world-wide attention 

and set a high standard for other countries to emulate. All can now recognize 

the benefits which these data and their analysis provide to unde rstanding regional 

and global geophysical phenomena. 

The success of NOAA's GMCC program is no accident. Aside from NOAA headquarters' unfailing support, the dedication of GMCC's personnel must take the 

greater part of the credit. In addition, NOAA is appreciative of the help of 

ma ny non-GMCC scientists who have used its facilities and have guided several 

highly specialized programs. 

The future of GMCC is promising. While the measurement programs will 

continue, indeed they will most likely expand, GMCC will increasingly use the 

data for the good of the country and mankind. 

v 

Lester Machta 

Director, ARL 
AL 

APCL 

APO 

ARL 

ASRC 

BOSS 

BRW 

CAF,CAQ 

CIRES 

CNC 

CSIRO 

DAS 

DOE 

ECC 

EML 

EPA 

ERL 

GARP 

GATE 

GMCC 

ICDAS 

MLO 

MPI 

NARL 

NASA 

NBS 

NCAR 

NESS 

NIP 

NOAA 

NSF 

NWS 

OGC 

SMO 

SPO 

SRBL 

STP 

SUNYA 

UNEP 

URI 

USDA 

UV 

WHO 

ACRONYMS AND ABBREVIATIONS 

Aeronomy Laboratory, Boulder, Colo. (NOAA) 

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

Astrophysical Observatory, Smithsonian Institution, Washington, D.C. 

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

Atmospheric Sciences Research Center, SUNYA, Albany, N.Y. 

Basic Operating Software System 

Barrow Observatory, Barrow, Alaska (GMCC) 

Clear Air Facility, Clean Air Quadrant, South Pole Observatory, 

Antarctica (GMCC) 

Cooperative Institute for Research on Envirorunental Science, Univ. of 

Colo., Boulder, Colo. 

condensation nuclei counter 

COlnmonwealth Scientific and Industrial Research Organization, 

Australia 

Data Acquisition System 

U.S. Department of Energy 

electrochemical concentration cell 

Environmental Measurements Laboratory (DOE) 

U.S. Environmental Protection Agency 

Environmental Research Laboratories, Boulder, Colo. (NOAA) 

Global Atmospheric Research Program 

GARP Atlantic Tropical Experiment 

Geophysical Monitoring for Climatic Change (NOAA) 

Instrument Controlled Data Acquisition System 

Mauna Loa Observatory, Mauna Loa, Hawaii (GMCC) 

Max-Planck Institute of Chemistry, Mainz, Germany 

Naval Arctic Research Laboratory, Barrow, Alaska 

National Aeronautics and Space Administration 

National Bureau of Standards, U.S. Dept. of Commerce 

National Center for Atmospheric Research, Boulder, Colo. 

National Environmental Satellite Service (NOAA) 

normal incidence pyrheliometer 

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

National Science Foundation, Washington, D.C. 

National Weather Service (NOAA) 

Oregon Graduate Center, Beaverton, Ore. 

Samoa Observatory, American Samoa (GMCC) 

South Pole Observatory, Antarctica (GMCC) 

Smithsonian Institution Radiation Biology Laboratory 

standard temperature and pressure 

State University of New York at Albany, N.Y. 

United Nations Environmental Program, Nairobi, Kenya 

University of Rhode Island, Kingston, R.I. 

U. S. Department of Agriculture 

ultraviolet 

World Meteorological Organization, Geneva, Switzerland 

vi 
GEOPHYSICAL MONITORING FOR CLIMATIC CHANGE 

NO. 7 

Summary Report - 1978 

1. SUMMARY 

1.1 Observatory Facilities 

Minimal facility additions and modifications were made during 1978. At 

Samoa the Oregon Graduate Center set up a prefabricated building adjacent to t he 

GMCC remote sampling tower on Lauagae Ridge to begin measuring fluorocarbons . 

Also at Samoa the GMCC emergency electrical power generator was replac e d. At 

Barrow a 2.5-m x 2.5-m wanagan was added to the GMCC Observatory facilities i n 

anticipation of initiating a lidar measurement program there. Six hundred c ub ic 

yards of gravel were added to the observatory road to help ensure access during 

all weather conditions. Although the South Pole new Clean Air Facility monit oring program was generally troublefree, modifications to the observatory powe r 

feed transformers were necessary to h andle the electrical power draw when all 

systems were operated. 

1 .2 Ongoing Programs 

Continuous CO 2 measurements at the South Pole were temporarily suspended 

during 1978. Continuous measurements at the other observatories were uninterrupted, and data processing was completed for the entire record. Monthly averages of CO 2 concentrations for Mauna Loa and Barrow are included in this report. 

The first CO 2 -in-air calibration gases were run at Barrow and Mauna Loa. Eventually all calibration gases will be converted from CO 2 -in-N2 to CO 2 -in-air. 

Companion CO 2 flask sampling at all the observatories was completed, and the da t a 

are included in this report. 

Dobson ozone spectrophotometers at six U.S. continental stations were 

inspected, calibrated and refurbished in 1978. In cooperation with the World 

Meteorological Organization participation in the upgrading and calibration of 

Dobson ozone spectrophotometers continued in 1978. Dobson modifications and 

calibrations for four foreign countries were completed. Monthly total ozone 

data obtained from daily data in the GMCC Dobson network were edited and are 

included in this report. 

Surface ozone measurements continued at the observatories. An analysis of 

diurnal, day-to-day, seasonal, and station-to-station ozone variations was completed and is included in this report. A stratospheric water vapor measurement 

program, initiated in 1978, will become an ongoing program for the GMCC. An 

indepth analysis of halocarbon and nitrous oxide data collected at the GMCC 

observatories was completed in 1978. Hemispheric concentrations, gradients , and 

lifetimes are given herein . 

At a ll the GMCC observatories surface aerosol measurements of small particle 

concentrations and light scattering characteristics were continued. Enough data 
have now been collected to begin to investigate secular trends and confirm 

seasonal variations. Solar radiation measurements at Barrow and Samoa were used 

to identify seasonal variability in atmospheric transmission . 

Precipitation chemistry measurements continued at the observatories, and a n 

analytical laboratory was established at Mauna Loa Observatory in Hilo to analyze 

samples from Hawaii, Barrow, and Samoa. Data showing the spatial and time 

variation of ph values are shown. 

The reliability of the Instrumentation Control and Data Acquisition Systems 

(ICDAS) at the observatories improved during 1978. Noise levels in the ICDAS 

were reduced to improve the quality of the data collected. 

1.3 Research Programs 

GMCC personnel conducted several special research studies in 1978 . A remote 

sensing technique to measure vertical ozone profiles by incorporating more Dobson 

wavelengths in the measurements was refined and evaluated against the older 

Umkehr method. An evaluation of the Robinson-Berger erythema meter measurements 

showed differences from the true erythemal spectrum obtained from measurements 

made with a double monochromater. More analysis will be done to determine the 

cause and significance of the differences. 

A study of vertical ozone profile measurements when volcanic erup tions eject 

effluent into the stratosphere showed that significant errors result in the 

measurements. A procedure to correct the ozone profiles for perturbations in 

stratospheric aerosol concentrations is described herein. Variations in the 

isotopes of atmospheric carbon from the addition of limestone CO 2 into the 

atmosphere was studied. An increase in carbon-13 amounts from the addition of 

limestone CO 2 to the atmosphere could be significant and should be taken into 

account in carbon-13 to carbon-12 ratio studies determining the effects of 

burning fossil fuel on the total atmo spheric CO 2 budget. 

Two solar irradiance studies that measure urban effects on incoming radiant 

energy were completed . In cooperation with the U.S. Department of Energy, 

measurements taken in the metropolitan St. Louis area were analyzed and showed a 

decrease of up to 3% in solar irradiance as compared to adjacent unpolluted 

areas. Measurements in Voeikovo and Leningrad, U.S.S.R., were taken to assess 

anthropogenic effects on incoming solar energy and to compare U.S . and U.S .S. R. 

turbidity instruments. GMCC personnel evaluated measurements at several sites on 

Mt. Kenya, Africa, for the Mt. Kenya Feasibility Study. The Feasibility Study 

was undertaken to determine the suitability of the area for potential baseline 

measurement locations. The GMCC evaluation noted that background conditions may 

occur on Mt. Kenya and recommended that more detailed analyses of the meteorologica l 

regimes that influence CO 2 and aerosol concentrations be undertaken. 

Atmospheric transmission data at Mauna Loa continued to show perturbation~ 

from explosive volcanic eruptions, the latest being Soufriere. The monthly 

transmission values for the 20-yr record are included in this report. Several 

solar-terrestrial studies were carried out to determine whether variations in the 

solar constant could be detected from past solar data. 

2 
1.4 Cooperative Programs 

In 1978 GMCC support for cooperative programs at the observatories doubled. 

Twenty-seven summary reports from cooperative programs are given in this report . 

Investigations of aerosol chemistry at Barrow and the South Pole were the major 

efforts of t h e cooperative programs for 1978. Programs in precipitation chemistry 

and trace gases were also expanded through cooperative efforts. GMCC measurement 

programs together with university and other federal agency cooperative programs 

provided a mu l tidisciplined effort in describing the trace levels of atmospheric 

pollutants a t the GMCC observatories in 1978. 

3 
2. OBSERVATORY REPORTS 

2.1 Mauna Loa 

2.1.1 Facilities 

The following modifications of the MLO facilities were carried out in 1978: 

(1) Two strip chart recorders were acquired; a Leeds and Northrup multipoint 

recorder replaced an antiquated Brown recorder to record pyrheliometric data and 

a new dual-channel Honeywell recorder was added for use in precipitation chemistry 

studies. 

(2) A new, improved solar tracker was purchased and installed, and the 

pyrheliometer and infrared hygrometer were transferred to it. 

(3) Although two different pyranometer shading rings were fabricated and 

tested, problems with them forced acquisition of an Eppley shading disc. The disc 

and its Sun-following mount were used in me asuring diffuse radiation. 

(4) A 13-channel pyrheliometer was refurbished and put into use for measuring 

direct radiation. 

(5) Condensation nuclei counts with the Gardner counter were discontinued, 

and the instrument was shipped to the mainland. 

(6) Lidar system optics were changed to improve system reliability. The 

efforts were partially successful . 

(7) The the r moscreen and precipitation collectors at Kulani Mauka were moved 

abo ut 300 m northwest to avoid interference from a new telephone building. 

(8) Six rainwater collection devices were installed in the volcano area for 

a short time as part of the Harding precipitation chemistry study. 

(9) The Applied Physics carbon dioxide analyzer was modified to try to 

improve its stability and performance. The ma in modifications were as follows: 

a. Replacement of vacuum tubes in the amplifier. 

b. Replaceme nt of the thermal control unit in the analyzer. 

c . Replacement of the photodiode and transistor circuit in the 

contact and phasing a djustment assembly. 

d . Replacement of strip chart recorder. 

e. Replacement of alcohol bath in freezing unit and installation of 

a double freeze-trap arrangement. 

f. Replacement of air sampling pumps. 

g. General rework of electrical circuits. 

h. Installation of thermal insulation for better temperature control 

of the device. 

4 
2.1.2 Programs 

Table 1 lists the programs carried out at MLO during 1978. Brief status 

reports of the principal programs follow: 

Carbon Dioxide 

Both the AP and URAS carbon dioxide analyzers operated without significant 

interruptions throughout the year. Identifiable signatures in the data produced 

by outgassing from the volcanic caldera at the summit of Mauna Loa were detected 

in the CO 2 measurements. They occurred mainly between midnight and 8 a.m. local 

time during a downslope wind flow regime on the mountain. The frequency of occurrence of the anomalous conditions is shown for the different months of 1978 in the 

following tabulation: 

J 

No. of days 9 

Percent 

occurrence 29% 

Atmospheric Ozone 

F M 

5 4 

18% 13% 

A M J 

11 6 11 

37% 19% 37% 

J A S o N D 

13 13 10 18 8 8 

42% 42% 33% 58% 27% 26% 

Total ozone in an atmospheric column was measured by the Dobson spectrophotometer on approximately 260 days of 1978, and the ozone concentration in air near 

the surface was measured continuously with Dasibi and EEC ozone meters. All three 

measurement programs operated satisfactorily, although a few problems were encountered in maintaining the chemical solution in the EEC meter. 

Sulfur Dioxide 

The S02 meter operated well after installation in January 1978, although some 

data were lost because of strip chart recorder problems. The S02 data show the 

episodes of fuming from the Mauna Loa volcano. 

Carbon Monoxide 

Except for short periods in early January and November, the carbon monoxide 

measurements continued throughout the year. The record co ntinued to show interesting variations that appear to be related to the changing of air mass types over 

the Pacific area. 

Atmospheric Aerosols 

The aerosol measurement program operated successfully throughout 1978. After 

minor repairs at the University of Washington, the nephelometer was reinstalled in 

late January and gave reliable measurements during the rest of the year. Faulty 

lamps forced termination of Aitken nuclei measurements by the Gardner counter, but 

equivalent data were obtained on a routine basis with the Pollak counter. The 

least reliable instrument in the aerosol program, the G.E. counter, required 

realignment and voltage adjustments but provided adequate continuous measurements 

of nuclei concentration. 

5 
Program 

Gases 

Carbon dioxide 

Surface ozone 

Total ozone 

Fluorocarbons 

Aerosols 

Stratospheric aerosols 

Condensation nuclei 

Optical properties 

Sola r radia tion 

Global irradiance 

Ul travi olet irradiance 

Direct beam irradiance 

fleteorology 

Max imum temperature 

Minimum temperatu re 

Ambient temperature 

Dewpoint tempera t ure 

Relative humidi t y 

Total precipitable water 

Pressure 

Precipitation 

Wind speed 

Wind direction 

Precipitation chemistry 

Aci dity of rainwa t er 

Conductivity of water 

Chemical components 

Cooperative programs 

Carbon dioxide (Scripps 

Ins t. ) 

Carbon monoxide (Max 

Planck lnst.) 

Total nitrogen dioxide 

(Aeronomy Lab/NOAA) 

Surface S02 (EPA) 

Table 1. - - Summary of monitori ng programs at flLO in 1978 

I nstrume nt 

URAS - 2 infrared gas analyzer 

Evacuated glass flasks 

Evacuated flasks 

Electrochemical concentration cell 

Dasibi ozone mete r 

Dobson spectrophot ometer 

Pr ess u rized flasks 

Lidar 

Pollak CN counter 

G. E. CN co unte r 

4-wavelength nephe lometer 

4 Eppley pyranometers 

Eppley ul traviolet pyra nome t er 

Eppley pyrheliome t er 

Eppley pyrheliome t er with f ilt ers 

Eppley 13- channel pyheliometer 

Maximum t hermometer 

fli ni mum thermome t e r 

Thermistor 

Hygrothe rmograph 

Dewpoint hygrometer 

Hygrot hermograph 

Faskett infrared hygrometer 

El ec t ronic pressure transducer 

flicrobarogra ph 

Rain ga uge, 8 ft 

Rain ga uge, tippi ng bucket 

Anemometer 

Wind vane 

pH meter 

Conductivity bridge 

Ion chromatograp h 

Infrared analyzer (Applied Physics) 

Evacuated flasks 

Special 

Spec trometer 

Sampling 

f r eque ncy 

Con t inuous 

Wee kly 

Wee kly 

Continuous 

Conti nuous 

Discre t e 

Wee kly 

Wee kly 

Discre t e 

Conti nuous 

Continuous 

Continuous 

Conti nuous 

Co ntinuo us 

Disc r e t e 

In t ermi t ten t 

Daily 

Da i ly 

Conti nu ous 

Co nt i nu olls 

Continuous 

Co nti nuous 

Conti nuous 

Co nti nuous 

Continuous 

Wee kly 

Continuo us 

Continuous 

Continuo us 

Discre t e 

Discrete 

Discrete 

Conti nuous 

2 mo- 1 

Continuous 

Continuous 

1 every 12 days 

Remar ks 

Mo un tain and seacoa st 

Fo r Okayama Uni v ., J apan 

3 meas . wee kdays ; 0 we eke nd s 

694 . 3 om, 1 J 

5 meas . we e kdays ; 0 we eke nd s 

Wave l e ngth s 450 , 55 0, 700, 850 nm 

Cutoff fil t ers at 280 , 390, 53 0, 

695 nm 

Wavele ngth range 295 to 385 om 

Wave l ength range 280 to 3000 om 

Cu t off f ilte r s a t 280, 530 , 630, 

695 nm 

Combine d with dew point 

hygrome t er 

At MLO a nd Kul a ni Mauka 

At MLO a nd Kul ani Mauka 

Chec ke d wi th merc uri a l ba r ometer 

At MLO a nd Kul Hni Mauka 

Ra inwa t e r co llec t. at 6 sites 

Mountai n and seacoast 

Chemica l reaction with HgO 

Total surface particulates 

(DOE) 

Chemical bubbler system 

High-volume filter Continuous Dependent on wind direction 

Total surface particulates High-volume filter 

(EPA) 

1 every 12 days 

Atmospheric electricity 

(APCL/NOAA) 

Stratospheric aerosols 

(AFGL) 

Ultraviolet radiation 

(Temple Univ . ) 

Precipitation collection 

(DOE) 

Precipitation collection 

(EPA) 

Precipitation co l lection 

(Univ . of Paris) 

Precipita t io n collection 

(lAEA, Vienna, Austria) 

Cloud water collection 

(SUNYA) 

Field mill, air conductivity meter , Contin uous 

surface antenna 

Twilight photometer Co ntinuous 

Ultraviolet radiometer 

Wet-dry Health & Safety Lab 

collector 

Misco model 93 

Likens fu nne l col l ector 

Like ns funn e l col l ector 

Cloud and fog col l ec t or 

6 

Continuous 

Continuous 

Conti nu ous 

2 wk- 1 

Co nt i nuo us 

Radiation responsib l e for s unbu r nin g of s kin 
Lidar 

Some equipment failures occurred during 1978 in the MLO lidar program. 

Measurements were made on a weekly schedule, but electronic malfunctions prevented 

complete measurements on some occasions. Optical components, flash lamps, and the 

cooling system were replaced to improve the measurements. 

Solar Radiation 

The solar radiation program was relatively troublefree, and many reliable 

data were obtained. The acquisition of a new equatorial mount and a new shading 

disc improved the overall quality of the data, and calibration checks reaffirmed 

the basic stability of instrument responses. Efforts to use the 13-channel pyrheliometer were initiated late in the year. 

Meteorological Parameters 

Temperature, pressure, wind, and other meteorological parameters were me as ured 

routinely with few problems. The dew cell installed for dew point measurements 

was inoperable for the entire year, but humidity data were obtained by using the 

hygrothermograph records. 

Precipitation Chemistry 

Precipitation samples from Barrow, Samoa, South Pole, and several sites in 

Hawaii were routinely analyzed. Vandalism at collection sites continued, and the 

unavailability of ultraclean water caused some interruptions in the analyses. 

A special sLudy of precipitation in the vicinity of the Kilauea Volcano was 

carried out by D. Harding. This program was quit e successful; the details are 

discussed in section 3.11 of this report. 

Fluorocarbons (Halocarbons) 

This discrete sampling program continued without difficulty in 1978. Weekly 

air samples were taken at the observatory and shipped to Boulder for a nalysis. 

Cooperative Programs 

The observatory cooperated with several agencies and organizations in meas uring environmental parameters during 1978. The main studies are the following: 

a. Measurements of sulfur dioxide - EPA. Changes in the operational 

procedures during 1978 included lengthening the sampling duration from 6 to 12 

days, shifting the cognizant laboratory from the mainland to Honolulu, and 

instituting quarterly calibration and maintenance visits by EPA personnel. 

b. Collections of atmospheric particulates - EPA. High-volume samplers were 

run continuously to collect total particulates. The only modification in 1978 was 

the provision of a backup sampler unit. 

c. Precipitation chemistry - EPA. Monthly precipitation samples were 

routinely sent to the EPA laboratory in North Carolina. The small quantity of 

water available for the samples was a problem; a different type of collector unit 

could eventually solve this. 

7 
d. Precipitation chemistry - DOE. The automatic collector used in this 

program separates wet from dry fallout, and samples are sent monthly to the 

central laboratory. A second part of this project is to intercompare the DOE 

monthly collections and MLO's shorter term collections to assess the effects of 

time lags in the analysis. No particular problems were encountered. 

e. Collection of atmospheric particulates - DOE. This project us es two highvolume samplers, one operated at night and the other during the day to distinguish 

the particulate loading of upslope versus downslope wind flows. No problems were 

encountered during the year. An interesting result of the measurements is that the 

"down-slope" filters sometimes appeared darker than the "upslope" filters since 

fuming from the Mauna Loa sununi t has become evident. 

ICDAS Computer Operation 

The MLO computer experienced some hardware difficulties in 1978; however, 

the actual data loss was kept to a minimum. Malfunctions of connectors, switches, 

and sockets in the tape unit and Chronolog clock resulted in intermittent computer 

failures from January through May. The tape unit connectors were replaced, and 

a new, improved clock was received and installed. A noise problem manifested by 

drifts of the zero offset a nd 5-V reference was traced to the multiplexer cabinet 

and improved by strapping the system units together and eliminating some spare 

cables . The multiplexer was believed to be out of alignment, and a repl acement 

was received in June. A bad address register board and a failure in the computer 

CPU board required repairs in June. Some drifting of the zero offset and 5-V 

reference was experienced during the latter half of 1978, but several grounding 

straps, line filters, and a replacement 5-V reference card improved the situation 

in October. 

2.2 Barrow 

2.2. 1 Facilities 

A standard 8 ft x 8 ft wanagan from NARL was added to the GMCC Barrow 

Observatory's facilities during 1978. Work was begun to convert the wanagan 

into a lidar observatory. Since some lidar observations were to be made after 

normal working hours during part of the year, it was decided to locate the 

observato ry within the NARL camp area, in walking distance of the GMCC staff's 

housing. 

Six hundred cubic yards of gravel were added to the most needy sections of 

the observatory's access road. Additional gravel and clay will be required as a 

binder during summer 1979 to stabilize the road's surface. This work should 

significantly improve the road's surface and extend its life. 

2.2.2 Programs 

1978 sampling programs for the BRW Observatory are summarized in table 2. 

In September, T. Harris visited the BRW Observatory to exchange the station's 

UNOR CO 2 analyser with a URAS-2T ana lyser and to intercomp are both analysers by 

using GMCC's CO 2 -in-air reference tanks. Beginning in August, as an additional 

check on the CO 2 sampling system, hand-aspirated CO 2 flasks were exposed on 

alterna te weeks as opposed to the pressurized flask pairs, which are exposed at 

the analyser. 

8 
Table 2.--Summary of sampling programs at Barrow during 1978 

Gases 

Monitoring programs 

Carbon dioxide 

Surface ozone 

Halocarbons 

Total ozone 

Instrument 

UNOR infrared analyzer 

URAS-2T infrared analyzer 

Glass flask pairs 

Electrochemical concentration 

cell (ECC) 

Dasibi ozone meter 

Flask samples 

Dobson spectrophotometer 

Aerosols 

Condensation nuclei 

Optical properties 

Solar radiation 

G.E. CN counter 

Pollak CN counter 

4-wavelength nephelometer 

Global spectral irradiance 4 Eppley pyranometers with 

Q1, GG22, OGl, & RG8 filters 

Eppley UV radiometer 

Direct spectral irradiance Eppley normal incidence pyrheliometer with filter wheel 

Turbidity Eppley sunphotometer 

Meteorology 

Air temperature 

Relative humidity 

Air pressure 

Wind speed & direction 

Ground temperature 

Thermistor 

Hygrothermograph 

Dew point hygrometer 

Hygrothermograph 

Transducer 

Microbarograph 

Mercurial barometer 

Bendix Aerovane 

Thermistor 

Sampling frequency 

Continuous 

Continuous 

1 pair wk- 1 

Continuous 

Continuous 

1 pair wk- 1 

Discrete 

Continuous 

Discrete 

Continuous 

Continuous 

Continuous 

Discrete 

Discrete 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

Discrete 

Continuous 

Continuous 

Precipitation chemistry 

pH and conductivity Wide-mouth polyethylene Discrete 

Cooperative programs 

Total surface particulates 

(DOE/ELM) 

Arctic haze particulates 

(URI) 

Global radiation (SRBL) 

N0 2 (Aeronomy Lab/NOAA) 

CO 2 sampling (SIO) 

Icc nuclei sampling 

(Univ. of Alaska) 

Soil Conservation 

Service's precipitation 

gauge (USDA) 

collector (samples 

analyzed at MLO) 

Collection of snow on tundra 2 times mo- 1 

at old east precip. sampling 

site (samples analyzed 

at MLO) 

High-volume sampl er 

High-volume sampler 

Eppley pyranometers 

Scanning UV radiometer 

Temple Univ. sunburning meter 

N0 2 spec trometer 

Evacuated flask 

Low-volume sampler, membrane 

fil ters 

Wyoming shielded 

precipitation gauge 

9 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

Discrete 

2 sets mo- 1 

set day-1 

2 times mo-] 

Data record 

~!a r 73-Sep 78 

Sep 78-present 

Apr 7l-present 

~!ar 73-present 

Jul 75-present 

Sep 73-present 

Aug 73-present 

~!ay 73 -Nov 74 

Apr 76-present 

Jul 73-present 

Apr 76-present 

Jun 74-present 

Jun 74-present 

Apr-77 -present 

Apr 78-present 

Nov 75-present 

Feb 73-

Nov 77-present 

? 

Nov 78-present 

Feb 73-

Sep 78-present 

Nov 75-present 

Feb 73-present 

~!ay 74-present 

Feb 73-present 

Nov 75-present 

Sep 77-present 

? 

Oct 78-present 

Aug 75-present 

Sep 76-present 

Apr 73-present 

May 75-present 

Sep 78-present 

Aug 75-Feb 77 

Jan 74-present 

Sep 78-present 

Mar 78-present 
In November BRW's surface 0 3 equipment, ECC #005-06, Dasibi # 13 23, and 

MacMillan 1000 ozone generator #313 were compared against GMCC's standard Dasibi. 

Beginning in April, turbidity observations were resumed. These data will 

be used in the study of the Arctic haze phenomenon. 

In May the air temperature thermistor was moved from the instrument shelter, 

placed in an aspirated shield, and installed on the meteorological tower approximately 2.5 m above the tundra. In July, the ground temperature thermistor was 

moved from near the tower (depth 5 cm) to approximately 18 m east of the tower 

(depth 30 cm). The observatory's mercurial barometer was returned to Boulder 

for a replacement after a second yearly calibration by NWS indicated an unacceptable drift in the barometer's calibration. After extensive repairs and modifications the dew point hygrome ter was made to operate on the data acquisition 

system (DAS) and since November has been taking good data. 

Because of renewed interest in the chemistry of the Barrow area precipitation, it was decided to start taking precipitation samples off the tundra surface 

twice a month to supplement the falling precipitation collection started in 

1977. The old precipitation chemistry station approximately 50 m east of the 

observatory was selected as the sampling site. 

A Temple University sunburning UV meter was added to SRBL's cooperative 

program in September. A new cooperative program with the University of Alaska's 

Geophysical Institute to sample ice nuclei was started in June. Ice nuclei 

filters were also exposed for a 2-wk period in April and May for the URI. 

Beginning in March BRW personnel took over the servicing of the USDA Soil 

Conservation Service's Wyoming shielded precipitation gauge. 

2.3 Samoa 

2.3.1 Facilities 

No major GMCC-originated scientific facilities were added during 1978. An 

addition was made, however, by the Oregon Graduate Center, Beaverton, Ore., as 

part of the Atmospheric Lifetime Experiment (ALE) for fluorocarbons. The facility addition consisted of a small prefab building erected adjacent to the GMCC 

remote sampling tower on Lauagae Ridge. R. Rasmusson of the OGC is responsible 

for the ALE operations in Samoa. 

Some facility replacement activity was required at Samoa. A serious problem 

was caused by failure of the Samoa Station emergency generator set in March. 

Lack of emergency power effectively destroys the day-to-day data continuity 

because of frequent power outages, which are not necessarily long, but which put 

the ICDAS offline until an operator can restart the system. A replacement 

generator set (Kato) was purchased and sent to Samoa soon after the failure, and 

was mounted to the engine after removal of the defective generator. Emergency 

power was restored on May 13. 

A factor that may have contributed to the original generator failure was 

moisture absorption by its windings. This problem should be effectively eliminated in the replacement unit by factory-installed resistance heaters which run 

continuously and keep the unit always warmer than its surroundings when not in 

use, thus slowing down corrosion processes and preventing moisture buildup. 

10 
Other equipment problems involved air conditioner failures including the 

primary central unit for the main building, the unit for our remote sampling 

building, and the unit for the Ash dome, which houses the Dobson #42. 

2.3.2 Programs 

1978 is the first full year of operation for the present complement of GMCC 

monitoring instrume ntation in Samoa's Southern Hemisphere tropical loca tion. 

Installations of equipment were completed in July 1977 with the aerosol progr am 

equipment the last major addition. Tab le 3 summarizes the 1978 sampling programs 

at the Samoa station. 

Although certain programs had difficulties during the year, overall continuity of the data record was not seriously affected. For purpo ses of discussion 

difficulties may be classed in four categories: (1) island a.c. supply problems 

and station emergency a .c. power supply problems, (2) instrument problems, (3) 

sampling problems, a nd (4) human errors. The first category , a.c . power supply, 

was the primary source of continuity problems, and has b een during the 3 years of 

operation in Samoa. Instrument probl ems are intermittent and usually short, a nd 

when longer p e riods of downtime are probable, interim substitution equipment is 

sent from Boulder. 

Samoan sampling probl ems are compounded by the humid tropical environment. 

The most serious 1978 sampling problem was encountered in the continuous CO 2 

program which used a rather long samp l e line of polyethylene tubing. The problem 

of apparently elevated CO 2 index values obtaine d after sampling through a poly 

line was addressed by installing a liquid water condensation trap ahead of the 

normal freezer trap system as near the line inlet as possible. The trap should 

prevent the humid sample air from condensing in the long sample line and causing 

water buildup . During the year various line lengths and line replacements were 

used. Air samples were taken from two locations : Lauaga e Ridge , where the GMCC 

remote sampling towe r is located, and Matatula Point, where the remnant URI 

tower and building are located. Sample line lengths are approximately 120 Oland 

350 m, respectively. 

A modified flask sampling schedule was also instituted; hand-aspir a ted 

flasks exposed at Matatula Point were alternated with through- the-analyze r 

sampl es to check on sample line effects. 

During 1978, R. Williams completed a series of reports on ICDAS performance 

in general areas of reliability, nois e characteristics of the system, a nd analysis of the kinds of system failures experienced. 

2.3.3 Cooperative Programs 

T. Fogg, URI Graduate School of Oc eanography, arrived in Samoa on the Woods 

Hole research vessel Knorr duri ng August . He spent about 2 wee ks sampling at 

Matatula Point as part of his graduate research. 

Other individuals from the Knorr also visited the observatory, and preliminary discussions were held concerning us e of Samoa GMCC site for Southe rn Hemis phere SEAREX work in 1980-81. 

11 
Table 3.--Summary of sampling programs at Samoa in 1978 

Monito ring programs (GMCC) 

Gases 

Carbon dioxide 

Surface ozone 

Total ozone 

Fluorocarbons 

Aeroso ls 

Condensation nu c l e i 

Scattering properties 

(surface a ir) 

Atmosp heri c turbidity 

Solar radiation 

Global spec tr a l irradiance 

Direct spectra l irradi a nc e 

Meteorology 

Temperature (air) 

Temp era ture (s oi l) 

Temperatur e (dew point) 

Relative humidity 

Wind (speed/direction) 

Pressure 

Precipitation c h emistr y 

pH and condu ctivit y 

Cooperative programs 

NO z (Aeronomy Lab/NOAA) 

Atmospheric Lifetime 

Experiment fluorocarbon 

program (OGC ) 

Rain col l ecti o n (DOE/EML) 

Rain col lection (EPA) 

Instrument 

URAS-2T NDIR analyzer 

Evacuated glass flasks 

Electrochemical concentration cell 

Dasibi ozone me ter 

Dobson spectrophotometer #42 

Flask sampling 

G.E. CN counter 

Pollak CN counter 

4-wavelength nephelome ter 

Volz sunphotometer 

4 Eppley pyranometers with 

quartz, GG22, OGl, RG8 filters 

Eppley NIP with filter wheel 

(OGI, RG 2, RG8) 

Eppl ey NIP/equatorial mount 

combination 

Thermistor 

Thermograph 

Psychrometer 

Max/min thermometers 

Thermistor 

Thermistor with LiCI dew cell 

Hygrothermograph 

Bendix aerovane 

Transducer (capacitance t y p e ) 

Microbarograph 

Mercuri a l barometer 

Orion ph met e r 

Bec kman conductivity bridge 

Samples sent to MLO for further 

analysis on ion chromatograph 

NO z spectrometer 

H-P 5840A gas chromatograph 

Wet/dry collectors 

Misco collector 

12 

Sampling frequency 

Continuous 

Discrete 

Continuous 

Continuous 

Discrete 

1 wk- 1 

Continuous 

Discrete 

Continuous 

Discrete 

Continuous 

Discrete 

Continuous 

Continuous 

Continuous 

Discre t e 

Discrete 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

Discrete 

Discrete 

Discrete 

2 day - l 

Discrete 1 h - 1 

Continuous 

Continuous 
2.4 South Pole 

2.4.1 Facilities 

All GMCC South Pole measurement programs for 1978 were carried out from the 

Clean Air Facility (CAF). Figure 1 shows CAF exterior design, and fig. 2 shows 

the South Pole station layout and CAF and sensor locations . The CAF is off the 

snow surface, and drifting around the base poles is nonexistent. However, a 

ridge of drifted snow has been compressed by foot traffic, 15 m downwind from 

the grid southwest corner. It posed no threat to the CAF or GMCC operations. 

The interior of the CAF consists of four isolated rooms and two common 

areas for short-term projects and storage. Figure 3 shows the building's interior layout and space allocations. GMCC occupies rooms 1 and 4, and portions of 

rooms 5 and 7. Figure 4 shows the layout of sensors and equipment on the CAF 

roof. 

Ambient air for continuous measurement instrumentation is obtained through 

two sampling stacks (see figs. 1 and 3). One is for gas sampling and has six 

taps inside GMCC room 1 to which lines are attached that run to the instrumentation. Flows are adjusted at the instruments. The other is for aerosols and 

maintains laminar flow to prevent aerosol destruction. Three isokinetic taps 

are located inside room 1 with lines to the aerosol measuring instruments. The 

stacks are 14 ~ above the snow surface. Except for a slight buildup of snow at 

both intakes, discovered during a visual inspection in September, the stacks 

were free of obstruction and the interiors were in excellent shape. No other 

problems were encountered with the system during the year. 

One CAF problem was localized contamination of sampled air. Four ways by 

which locally contaminated air can reach GMCC instrumentation were evident during 

the year: (1) contamination from the CAF , (2) station contamination in winds from 

225° to 270°, (3) station contamination during periods of calm in strong temperature inversions, and (4) violations of the integrity of the CAQ. These instances 

were isolated, however, since the predominant polar winds eliminated (2) and (3), 

and regular inspection and scrutiny eliminated (1) and (4). Little if any data 

loss resulted from contamination. 

The major problem encountered in the CAF during 1978 was the inadequate 

power s upply from the station power plant. A greater than anticipated amperage 

draw by air sampling pumps of another CAF project (Univ. of Maryland, S-250) was 

noticed in February. This caused the transformers in the power plant and CAF to 

l3 

Figure 1. --New South Pole CAF constructed during summer 1976-1977. 
-

To 

Summercamp 

-

To G.CA 

/

TO 

Cargo Yard 

"'" 

Ice Crystal Hut 

o 

Sky lab 

""' ....... 30.5m. GMCC 

....... " jeMet Tower 

New CAF 

~ 

Snow Temp UC Dav Is 

·' 2 2m ~et Towers (Defunct) 

ERDA Hut -i.}-61m - e />1 /,E fec trlc Field Meter 

Atmos -1- A" / Ear1 h Current 

c::- I Elect ~ 0 

.... '30' 0 

0, I Acoust ic Sounder 

Antennas 

I 

I oOld CAF Rlo --- me - -- ter 

Ant en nas I Met.\ower 

I 

I 

I 

I 

I 

I 

335 Meters 

Grid East 

From O ld CAF 

Figure 2.--Amundson-Scott Station, South Pole, Antarctica, 1978 . 

overheat and reach a core temperature of 170 0 F, burning insulation, and causing 

deterioration. Stopgap measures to alleviate this situation prove d inconclusive. 

Finally, in April, a l arger capacity transformer to service the CAF was installed in the power plant and a separate transformer for the S-250 pumps was 

junctioned in at the CAF. All other CAF programs, including GMCC, were left on 

the original transformer . This solution was adequate but left the CAF without 

backup transformer capabilities for the winter. 

2.4.2 GMCC Programs 

ICDAS 

ICDAS p erformed excellently throughout 1978. No difficulties were encountered 

with the NOVA, Xerox multiplexor-digitizer , TTY, or Chronolog clock. Printed circuit board edge connector cleaning, digitizer z eroing, and TTY lubrication were the 

only preventive maintena nce required. 

Two small problems were encounte\ed with the ma gne tic tape drive during the 

year. From January to March 1978, EOFls being left on tape were traced to a 

loose pin on the tra nsport control board. In August, the BOT was not sen sed 

during a tape rewind, c ausing damage to transport control board components . 

Repa irs were effected by installing the spare board with new components and 

modified jumpers to match the NOVA interface . 

14 
-, 

E 

<D 

"-

/c. ~:'.:' .. Sl-" ~ 

Rm 1 

Com_ 

StOI.;' 

~ :,:;::::. D 

.~ . Commol'l 

Wo" ... , •• 

.~, 

SUN T .l.'ban, 

D 

.~. 

NO"" G"CC 

Rm 5 

N04 .. G"CC 

.. NO"""WPl. 

[] 

Figure 3.--Interior plan of new CAF, South Pole, Antarctica, 1978. 

17.1m. 

• Grid North I Sampling Stacks 

C@ 0000000 D " 

D D Unlv o t Maryland 

AI[ Sampl ing Stacks 

Atmos Conductivity Dobson Hat ch ERDA / HASL 

Pump Enclosure 

0 

UV Radiometer 

GG RG NWS NIP 

r'~ (.J !:::l (.J I 0 

Q OG 

Pyranometers 

J J 111111111 1111111 

Figure 4. --Roof plan of new CAF, South Pole, Antarctica, 1978. 

15 
Because of acceptable steadiness of station power and the lack of correct 

schematics and components necessary to construct a phase-locked loop driver 

board for the static transfer switch, the Deltec U.P.S. was not used for most of 

the year . 

No software problems were encountered. BOSS 76186 was used from November 3, 

1977, to December 14, 1977, when BOSS 77280 was put on line and run for the 

remainder of the year . Major improvements to the new version include a simplified startup sequence, TTY output for CO2 calibration sequence, and a revised 

method for ECC surface ozone data collecting and calibration. 

Carbon Dioxide 

Continuous sampling was performed throughout the year using the URAS-2T 

analyser, plus Cryo-cool refrigeration unit, solenoid switching valves, and the 

working calibration, and zero gases. For discrete sampling a pair of glass 0.5-Q 

flasks we re exposed twice monthly by diverting air from the analyzer's sampling 

line during the working gas cycle. Working gases were changed twice during the 

year, calibration and zero gases once. New IR sources were installed in March. 

Noise was minimal for most of the year, especially after the new sources stabilized. Slow downscale output drift was seen sporadically during the year, 

necessitating regular zero adjustments and analyzer realignments. 

Surface Ozone 

BOSS 77280 brought new methods for data handling and calibration. The 

Dasibi used a self-scaling routine written in the software. The ECC low calibration routine was relay controlled and TTY initiated. Zero ozone voltages for 

7 minutes were automatically transferred to the offset D-array registers. The 

scale factor was computed and entered by SR and TTY. 

All ECC problems centered on the cell. Those on line were recharged 

regularly, and one previously thought bad was washed in a mild nitric acid 

solution to clean the platinum screen and sensing chambers. As a result the 

output was increased and steadier. The Dasibi UV light source caused the most 

trouble. Power surges due to restoration after outages cracked the sources and 

diminished their stability. Sources were changed fairly frequently to try to 

keep the strongest and steadiest on line and to maintain maximum instrument 

reliability. 

Aerosols 

The aerosol program depended on three measuring instruments. A Pollak CNC 

and a long tube Gardner counter were used for discrete measurements, and a G.E. 

CNC provided a continuous record for the year. 

After extensive mechanical and electronic overhauling in November 1977, 

requiring a I-mo down period to await replacement partial main board and spare 

transistors from Boulder, the G.E. performed excellently for the year. Regular 

calibration and routine maintenance were all that were required for optimum 

performance. 

Pollak observations were taken three times every 24 h, throughout most 

of the year. One observation always corresponded to the daily SPO Meteorological 

16 
Office radiosonde flight. Cleaning a nd preventive maintenance were performed 

regularly. No problems were encountered with instrument operation . Concentra -

tions below 10 cm- 3 were seen throughout the winter . One Gardner observation 

was made daily, corresponding to a Pollak observation. Preventive maintenance 

was required every 10 days, and deflections corresponding to concentrations as 

low as 12 cm- 3 were obtainable. 

Solar Radiation 

The program consisted of discrete measurements of normal incidence and 

continuous measurements of both global spectral irradiance and normal incidence 

irradiance. The standard instrumentation (table 4) was us ed. In Decemb er 1977 

a nd January 1978, a series of special observations was made using the station 

filter wheel NIP and the traveling standard NIP and filter wheel to generate an 

intercomparison between the station and standard NIP both on the clear filter, and 

a correlative factor between the station and standard filter wheel, when both were 

on the standard NIP. Between November 1977 and January 1978, the traveling standard 

quartz pyranometer was installed and placed on line to provide an intercompa rison 

between it and the station quartz pyranometer. 

Ice crystal buildup on the domes was the major problem during the year. A 

new type of ring blower was installed in November. This ring clamps to the 

perimeter of the guard disc, and warmed air from the Thomas pump is forced out 

small holes in the ring. The old system forces the air up next to the dome 

through a ring under the disc. After intercomparing the two, it was decided 

that the newer rings were less efficient, and the old system was reinstalled on 

all pyranometers. 

Meteorology 

The six recorded parameters in table 4 make up the meteorology program. 

The only problem with recorded wind directions was related to some type of 360° 

to 540° scale expander card instability in winds from grid north (000°). Card 

modifications proved inconclusive, and because it was a sporadic problem and did 

not affect the resultant wind calculation, no further attempts were made to 

alleviate the instability. Low wind speeds when compared against station Meteorology Office values proved a puzzle for the first part of the year . Eliminating 

excess resistance from the signal receiving unit reduced the difference . In 

late November 1977 a new generator with newer bearings and brushes was installed 

in the aerovane. This further reduced, but did not eliminate, the difference. 

The problem was traced to excess capacitance across the input terminals acting 

like a resistor. Removal of this, however, fed the reference voltage onto the 

signal line, giving intermittent speeds around 35 m s-l. Card modifications in 

January and February 1978 reduced this to a sporadic occurrence only when wind 

speeds were high and gusty. After these modifications, GMCC wind speeds were 

still 10% lower than those of the station Meteorology Office. However, when the 

voltage output of the Meteorology Office aerovane was checked against BendixFriez documentation, its speed was fast by 1.5 kt over a range from 5 to 20 kt. 

This could account for the difference. 

A daily intercomparison between GMCC pressure values and the station Hg 

barometer, begun in March 1978, was stopped when the barometer was found to need 

repairs. The pressure transducer and temperature sensors operated for the year 

with no problems. 

17 
Table 4.--Summary of sampling programs at South Pole in 1978 

Gases 

Monitoring programs 

Carbon dioxide 

Surface ozone 

Total ozone 

Fluo roca rbons 

Aerosols 

Condensation nuclei 

Optical properties 

Solar radiation 

Instrument 

URAS-2T NDIR gas analyser 

0.5-£ evacuated glass flasks 

Electrochemical concentration 

cell 

Dasibi ozone meter 

Dobson spectrophotometer 

300-ml stainless steel 

sampling cylinders 

G.E. CN counter 

Pollak CN counter 

Long-tubed Gardner CN counter 

4-wavelength nephelometer 

Global spectral irradiance 4 Eppley pyranometers with 

quartz, G6-22, OG-l, and 

RG-8 filters 

Ultraviolet radiometer 

Direct spectral irradiance NIP on meridional tracker 

~leteorology 

Air temperature 

Air temperature 

Snow temperature 

Snow temperature 

Pressure 

Wind speed and direction 

Atmosphere moisture 

content 

Miscellaneous 

Room temperature 

Cooperative programs 

Carbon dioxide (SIO) 

Total surface particulates 

(Atmosphere trace metals) 

(DOE/ERDA/HASL) 

Turbidity (NOAA/ARL) 

Carbon-14 sampling 

(NOAA/ ARL) 

Atmospheric electricity 

(NOAA/APCL) 

Thermal radiation budget 

(NOAA/APCL) 

Acoustic echo sounding of 

planetary boundary layer 

(NOAA/WPL) 

Ionospheric opacity 

(Univ. of Calif . , San 

Diego; NOAA/EDIS) 

Filter wheel normal incidence 

pyrheliometer with quartz, 

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

Thermistor (aspirated shield) 

Thermistor (naturally ventilated shield) 

Thermistor 

Thermistor 

Transducer 

Bendix-Friez aerovane and 

recording system 

Dupont 303 moisture monitor 

Thermistor 

5-£ evacuated glass flasks 

Motor driven rotary lobe 

blower (high-volume air 

sampl ing through filters) 

Dual wavelength sunphotometer 

Pressurized steel spheres 

Atmospheric conductivity meter, 

electric field mill, air/ 

earth current antenna 

Net infrared radiometer 

Monostatic and bistatic echo 

sounding system 

30- and 50-~rnz riometers 

18 

Sampling frequency 

Continuous 

2 pairs mo- 1 

1 pair wk- I 

Continuous 

Continuous 

Discrete 

2 pairs rno - 1 summer 

1 pair mo- 1 winter 

Continuous 

Discrete, 2-4 day 1 

Discrete, 1 day-l 

Continuous 

Continuous during 

austral summer 

Continuous during 

austral summer 

Continuous during 

austral summer 

Discrete during 

austral summer 

Continuous during 

austral summer 

Continuous 

Continuous during 

austral swmner 

Continuous 

Continuous 

Continuous 

Continuous 

Continuous 

2 mo -1 (3 flasks 

per sampl e) 

Continuous (filters 

changed 4 times mo 

Data record 

Jan 75-Nov 78 

Jan 75-Nov 78 

Dec 78 

Dec 7l-Jan 79 

Jan 76-present 

Dec 63-present 

Jan 77 -Dec 78 

Jan 74-present 

Jan 74-present 

Jan 74-present 

Jan 79-present 

Feb 74-present 

Feb 74-present 

Oct 75-present 

Jan 77-present 

Dec 75-Jan 78 

la r 77 -present 

Dec 7S-Jan 78 

Jul 77-present 

Dec 75-present 

Dec 75-present 

~la r 77-present 

Jul 78-present 

1957-present 

May 70-present 

I) 

Discrete during Jan 74-present 

aus tra 1 summer 

500 P.S.I. ambient air Jan 74-present 

day-I, for 6 days 

Continuous 1973-Nov 78 

Continuous 

Continuous 

Continuous 

Terminated 

Feh 78 

Turn e d over to 

WPL pe rsonnel 

Jan 78 

1974-pres ent 
The Dupont mo isture monitor dynapump was rep l aced in late Decembe r 1977 

with a smooth er and less noisy metal b ellows pump . The only operational problem 

during the year was shorting of phosphorus pentoxide sensing cells b ecause of 

moisture buildup in the pump b eing injected rapid l y into the cell after power 

restorations . The s horting \\las elimina t ed by allowin g the pump to f lus h for 10 

mi nu tes before reattaching to the instrument. 

Fl uorocarbon s 

The r evised samp ling system (see GMCC Su~n ary Report 1977) was u sed t hroughout 1978 . \.Jin ter sampl es were mailed to Boulde r inuned i ate l y after the station 

opened . No leaks in the syst e m or probl ems of a ny type were encountered. 

Total Atmosph e ri c Ozone 

Dobson s pectrophotometer ob serva tions we r e ma d e fro m the CAF fo r the entire 

year . In early Novemb er, the times of the 2200 and 0200 CUT ob servation s were 

altered by as mu ch as one h o ur. This was d o ne to provid e ground truth for, and 

matc h the predicted times o f, the solar overpa ss of the F2 satell i te NFT ozone 

sen so r, at the requ es t of J. Lov ill, Satellite Ozone Analysis Center, Lawrence 

Livermore Laborato r y, Uni v . of Calif. A bad pho t omultiplier tube, discovered 

and rep l aced in December 1977, was the o nly malfunction during the year. 

Coopera tive Programs 

As a part of CAF operations, GMCC maintained cooperative programs for the 

i n stitutions listed in table 4. No strain on GMCC personnel or equipment 

occurred, a nd the quality a nd quantity of GMCC d ata were n o t affected. Coope rative programs e nhan ced CC'S polar presence and the fun ctioning of the 

CAF. 

19 
3. CONTINUING G~ICC PROGRAl'IS 

3 . 1 Carbon Dioxide 

3.1 . 1 Analyzer CO 2 Measurements 

During 1978, atmospheric CO 2 concentrations were continuously monitored by 

nondispersive infrared gas analyzers at the four G~lCC observatories. Ana lyzer 

measurements at South Pole were discolltinued on November 19, 1978 . 

The output from each analyzer was simultaneously recorded digitally by 

ICDAS and in an analog form by a strip chart recorder. Hourly CO2 values were 

obtained by using data processing procedures described in GMCC Summary Report 

1977 . 

Editing the hourly CO 2 data collected since the beginning of the GMCC 

monitoring program at Barrow (July 1973) and Mauna Loa (May 1974) has been 

completed. Mauna Loa Observatory CO 2 data bases for the first four years (May 

1974 through June 1978) have also been updated by using revised values for the 

working reference gases. 

Special calibrations, which used CO 2 -in-air standard mixtures, were carried 

out at Barrow during August 1978 and at Mauna Loa during September 1978 to 

obtain data for calculating pressure broadening corrections. These corrections 

are necessary when CO 2 -in-N2 standards have been used with an infrared gas 

analyzer to determine atmospheric CO 2 concentrations . Pressure broadening 

(sometimes called carrier gas effect) errors result when the proportions of N2 

and O2 in the reference gas mixtures differ markedly from those in natural air. 

The sensitivities of different analyzers to ~re~~ure broadening errors vary, and 

apparent measured CO 2 concentrations may be grea t er or s mall er t han when ca l ibrated mixtures of air are used as reference standards. 

Since inception of the mIce CO 2 monitoring program at Barrow, three different 

infrared analyzers have been used during the following time periods: 

Analyzer Serial no. Period of use 

UNOR-2 631521 July 73 - Aug 12, 75 

Aug 1, 76 - Aug 14, 78 

UNOR-2 631268 Aug 12, 75 - Aug 1, 76 

URAS-2T 0111 Aug 14, 78 -

At Hauna Loa Observatory, only one analyzer, a URAS-2 (serial no. 37626682), has 

been in use since the beginning of the measurement program in May 1974. 

Honthly mean 

values for Barrow 

to December 1978. 

expressed in the 

are given in the 

CO 2 concentrations have been computed from edited hourly CO 2 

for July 1973 to December 1978, and for Mauna Loa for May 1974 

The data are s hown in tables 5 and 6 . Values in column a are 

Scripps 1959 adjusted index scale, whereas those in column b 

1974 ~m CO 2-in-air mole fraction scale with tentative pressure 

20 
Table 5.·-Barrow Observatory monthly mean CO2 co ncentrat i on s": 

Nonth 

Jan 

F,b 

tla r 

Apr 

May 

Jun 

Jul 

Aug 

S'P 

Del 

Nov 

Dec 

1973 

b 

327 .13 324 42 

325 49 322 65 

328 29 325 64 

332 63 330 26 

336. 19 334 03 

336 56 334 43 

-:·Value!> exp re ssed in ppm. 

19 74 

a b 

340 93 339.06 

338 . 77 336 . 77 

339 48 337.52 

340 .71 338.83 

33927 337.3 1 

338 38 336.36 

333 . 30 330.97 

328 .14 325 49 

328.95 326 35 

332 41 330 OJ 

335 43 333 23 

338 61 336 61 

19 75 19 76 19 77 1978 

b b a b b 

340 35 338 45 339.46 337.51 338 64 336.63 34 1.1 8 339 34 

340 57 338 68 339.70 337 . 75 338 84 336.85 342 00 340 20 

340 09 338. 17 3406 1 338 . 72 340 06 338. 15 343 40 341 .69 

340,38 338 48 340.73 338 85 34091 339 .04 342.77 341.02 

34 1. 4 1 339 58 340. 11 338 30 341 .06 339 . 20 34255 340.78 

338 .06 336 . 02 339 05 337 . 07 33967 337.73 34 1. 37 339.53 

332 . 30 329 . 91 333 54 33 1 . 23 33248 330. 10 334 .25 33 1. 98 

327.41 324.71 326 5 1 323 75 329.34 326.76 327.23 328.28 

328 38 325.75 327.74 325 06 330.5 1 328 00 324.44 328.64 

332 52 330 . 17 332.41 330.03 334 40 332.14 327 . 73 332 29 

337.36 335 . 27 336.27 334. 13 336 98 335 84 333 .1 9 338 .10 

338.95 336 96 338.43 336.41 340 62 338 . 74 333 .63 338 59 

broadening corrections appli ed. Figure 5 shows plots of the data in the 1974 

\-INO mole fraction scale . 

The data presented are preliminary; e.g., all Barrow data must yet be 

updated with revised CO 2 concentration values for the working reference gases. 

Estimates of t he pressure broadening corrections will be improved. Pressure 

broadening corrections for UNOR-2 instrument (serial no. 631268), operated at 

Barrow from Augu st 12, 1975, to August I, IY 76, have not yet been determined; 

instead, corrections derived for the UNOR - 2 (serial no. 631521) instrument have 

been used. The pressure broadening characteristics of the two instruments are 

believed to be s ufficiently similar (Pearman, 19 77) to warrant application of 

this initial data adj ustment procedure . Relative errors in the data sets plotted 

Tab le 6.--~launa Loa Obse rvato ry monthly mean CO2 concentrations 

Nonth 

Jan 

Feb 

aar 

Apr 

~lay 

Jun 

Jul 

Aug 

Sep 

Del 

Nov 

O,e 

a 

328. 92 

327.88 

326 .68 

324.76 

323 29 

323 .1 5 

324 .28 

325 55 

1974 

b 

332.87 

331.76 

330 49 

328 44 

326 88 

326.73 

327 .9 3 

329 . 28 

"-"Values expressed in ppm. 

a 

326.62 

327 . 34 

327.95 

329 02 

329 59 

329 06 

327 .41 

325 .66 

324 40 

324.72 

325.60 

326 . 85 

19 75 

b 

330 42 

33 1.19 

33 1. 84 

332.98 

333 58 

333 02 

33 1.26 

329 40 

328 06 

328 40 

329 34 

330 67 

327 .68 

328 59 

329 28 

330 . 52 

330.73 

330 .19 

328 57 

326 49 

325. 10 

324 91 

326.12 

326.57 

21 

1976 

b 

33 1. 55 

332 52 

333 25 

334 58 

334 80 

334 22 

332.50 

330.28 

328 81 

328 60 

329 89 

330 37 

328 77 

329 .14 

330 62 

331.78 

332.4 1 

331.84 

330 29 

328 36 

327 21 

32 7.36 

328 61 

329.83 

1977 

b 

332 . 7 1 

333 .11 

334 68 

335 92 

336.59 

335 . 98 

334 33 

332 27 

33 1 .05 

33 1.21 

332.54 

333 84 

a 

330 96 

33 1.17 

332 .18 

333 49 

333 64 

33J 60 

332 . 10 

330 .13 

328 07 

328 42 

329 63 

330 69 

1978 

b 

335.05 

335 . 27 

336.35 

337.75 

337 91 

337 86 

336 26 

334 .1 6 

331.97 

332 34 

333 63 

334. 76 
E 339 a. 

a. 

c I :::t 

8 327~ 

\-

J". 

, . 

, 

'; 1 

\ . . , 

r. 

" 

\, 

• 

• 

:\ 

. " 

, 

.. ' 

, , 

J 1974 J 1975 J 1976 J 1977 J 1978 

, . 

Figure 5.--Mea n monthly CO 2 mixing 

ratios for Barrow, Alaska (solid 

line) a nd Mauna Loa, Hawaii (dashed 

line) plotted in SIO 1974 mole fraction CO 2 -in-air scale . 

in fig. 5 are estimated to be <1 ppm for the Barrow data and <0 .5 ppm for the 

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

±l ppm when referred to an absolute CO 2 mole fraction calibration sca l e . 

CO 2 analyzer data for South Pole and Samoa stations are no t presented in 

this report since an analyzer problem was experienced at South Pole and an air -

intake line problem was enco untered in Samoa during 1978. Final data processing 

from these stations has been postponed pending receipt of more CO 2 data and 

additio nal information about the performance of the analyzer system at these two 

stations. 

3.1.2 Flask Sample CO 2 Measurements 

Collection of pairs of atmospheric ai r samples in 500 crn3 double-stop-cock 

glass flasks continued at the four GMCC observatories and other sites during 

1978. Full-year dala are available from eight stations shown below : 

Station Sampling frequency Analytical standards 

Barrow, Alaska pr wk- ' CO 2 -in-N2 

Ni\vot Ridge, Colo. 1 pr wk_l CO 2 -in-N2 

Key Biscayne, Fla. 2-3 pr mo- 1 CO 2 -in-N2 

t-launa Loa, Hawaii 1 pr \<"k_l CO 2 -in-N2 

Cape Kumukahi, Hawaii pr wk- ' CO 2 -in- N2 

Cape Ma ta tula , Am. Samoa 1 pr wk - 1 CO 2 -in-N2 

Palmer Station, Antarctica 1 pr wk- I CO 2 -in-air 

South Pole, Antarctica 2 pr mo- 1 CO 2 - in-air 

Two methods were used to co llect the Barrow, Mauna Loa, and Samoa sampl es . 

The practice of filling the flasks by flushing with air from the CO 2 analyzer 

air intake system was alternated at weekly intervals with hand aspirating air 

22 
into the flasks outdoors while facing into the wind. The South Pole samples 

were collected by the CO 2 analyzer air-intake system, except after November 7 

when the manual aspiration technique was employed . Flask air samples at all 

other stations were collected by the hand-a spiration technique. All flask samples 

were analyzed with a Lira (Hine Safety Appliance) infrared analyzer, model 202, 

(serial no. 207 19). Samples from the first six stations were returned to Boulder 

as soon as pra ctica l after collection (usually within 1 to 2 weeks), and analyzed 

within a few days to a month thereafter. The Palmer, Antarctica, and South Pole 

samp les were received in Boulder early in 1979 and were analyzed during the period 

of ~Iarch I to April 12, 1979. 

Flask data in this report are presented in the Scripps 1959 adjusted index 

sca l e . All data are provisional. The data from the first six stations were 

obtained by using CO 2 -in-N2 calibration gas standards, and must be corrected for 

pressure broadening after conversion to the 19 74 Wl'IO CO2 -in-N2 mole fraction 

scale. All data are subject to corrections when final concentration values are 

determined for t he calibration gas standards. 

Hean monthly CO 2 mole fractions expressed in parts per million (ppm) Scripps 

1959 adjusted index scale are pre sented in table 7 for Barrow, Niwot Ridge, Key 

Biscayne, auna Loa, Cape Kumukahi, Cape Matatula, Palmer, and South Pole. Plots 

of the data are shown in fig. 6. Sample values enclosed in brackets in the plots 

have been visually judged to be outliers and have not been used in computing the 

mon thly mea n CO 2 concentrations. In addition, a small number of outliers lying 

outside the range of the plots have been excluded from the monthly mean value 

computations. The monthly mea n CO 2 mole fractions in table 7 have been determined 

from CO 2 measurement val ues where analySis values of two flask sa mpl es collected 

qua si-simul taneously represent one measurement result; also, a single sampl e value 

represents a measurement result in instances where its pair value is unavailable 

(e.g., because of a broken flask) or is deemed to be an outlier. The number of 

measurements made per month, the number of flask samples collected each month, and 

the number of sample values judged to be outliers per month at each station are 

indicated in tab l e 7. 

3.2 Total Ozone 

3.2 . 1 Ro utine Observing Program 

Routin e total ozone observations were continued in 19 78 at the four GHCC 

sta t ions, one foreign cooperative s tation, three domestic cooperative stations , 

t h ree NWS stations, and GHCC headquarters, Boulder. 

Figure 7 l ists the 12 stations of the U. S. Dobson ozone spectrophotometer 

netv/ork, the instrument number s, the agencies responsible for taking observations, 

and t he periods of record when observations were made. 

Other instruments under NOAA/GHCC control are: no . 94, to be installed at 

a U.S. \,e s t Coast station in California; no . 83, the world standard Dobson ozone 

spectrophotometer; no. 65, on loan to the University of Michigan; no. 93, loaned 

to Brazil; no. 8 1, loaned to Australia; and no. 38 in Boulder, a secondary 

standard instrument. 

23 
Table 7. --1978 provi si onal mean monl.hly CO 2 con central. ions from fI ask salnp 1 i ng 

--= Barrow NiwOl Ridge Ke:i Biscaxne Mauna Loa 

Mean No. of No. of No. of Mean No. of No. of No. of Mean No. of No. of No. of Mean No. of No. of No. of 

Monl.h cone. Ineas. flasks oullicrs cone. meas. flasks oul.liers cone . Ineas. flasks outliers cone. mcas. flasks oul.liers 

Jan JJ6 40 4 8 334 56 3 6 I 334.87 3 4 2 331.56 3 6 

feb 337.76 5 10 334 44 I I 3 334 90 I 2 332.37 4 8 

H" 340.12 2 3 335.12 2 4 335.54 3 5 333 40 4 8 

Ap' 338 57 4 8 338 22 I 2 338 00 2 4 334.46 4 8 

H,y 337 34 3 6 4 336 40 3 5 336.73 3 6 335.21 2 6 2 

JUIl 337 02 5 12 334 24 4 7 334.45 2 4 333.86 4 8 

Jul 330.72 5 • 331.82 3 6 4 332.40 2 4 332.56 3 5 

Aug 327.00 4 8 328.61 3 6 330.48 3 5 330.54 4 7 

SCI' 326 83 4 8 329.14 3 6 330. 33 I 2 329.54 5 10 

Del 332 20 4 8 330.69 3 5 I 330.76 2 4 2 329. IS 4 6 2 

Nov 335.13 4 4 332.12 5 10 2 333.43 3 6 330 50 4 10 

Dec 335.2' 5 • 334.32 2 333.36 2 4 331.28 5 10 

Tol.al 4, .3 5 32 60 13 27 50 6 46 .2 6 

.c- '" 

Cape Kumukahi Capc Mal.alula Palmer Sl.alion Soul.h Pole 

J,n 333 69 2 4 4 33 1.30 2 4 328.06 2 4 329.01 3 6 

Feb 333.74 5 10 331.06 I 2 , 327.98 3 6 329.06 I 2 

H" 334.16 3 6 331.93 4 6 5 32 •. 6. 5 • 328 41 2 4 

Apr 334.50 4 7 331.40 4 8 330.50 3 6 328 58 2 4 

H,y 335 62 5 9 331.88 3 6 2 330.19 4 8 328.78 2 2 2 

JUIl 336 07 3 6 332.06 3 6 331.47 5 9 329.08 2 2 2 

Jul 331.96 4 8 331.98 4 7 330 40 4 7 329.42 2 4 

Aug 330 21 5 9 331.17 2 4 330 63 5 10 330.13 2 4 

Sep 327.44 4 8 331.26 4 8 331.02 3 5 2 330.35 2 2 2 

Del 329.58 5 10 332.11 3 6 330.55 3 6 2 330.91 2 3 

Nov 332.15 4 8 331.14 2 331.18 4 7 331.05 I 2 

Dec 332.66 3 6 332.61 i4 330. 17 4 8 330.33 2 4 

TOl.al 47 91 7 38 73 10 45 85 7 23 3' 7 
340 

336 

332 

328 

324 

320 

336 

332 

328 

~ 324 Q, 

N 

o 

u 

328 

324 

340 

336 

324 

~ 340 

* , . . ' 

• '. ',. ;0 336 I ,r ~~ . . '. 

(. ) 

" (. ) 332 

328 

.. 324 

Barrow, Alaska 

340 

336 x x x .II 

. '. 

'. 

Key Biscayne. Florida 

. . . " .' . 

.. I x , x .. _ 

.. 

Cape Kumukahi, Hawaii 

(.) (. ) 

Palmer Station, Antarctica 

• . , 

(. ) 

, . 

. . ' . 

(. ) 

(. ) 

JFMAMJJASOND 

1978 

332 

328 

E 324 Q, 

Q, 

340 

336 

332 

328 

324 

320 

340 

336 

332 

328 

324 

320 

Figure 6.--Pl ots of 19 78 CO 2 f la sk sample data . 

expressed in SIO 1959 adjusted index scale. 

'. 

J 

(.) 

( .. ) (x) 

" . , . . ' 

Niwot Ridge. C olorado (x) 

... ~ 

" . :

(.) 

(.) 

x.. x !. ~ •• ,. . .". x. 

Mauna Loa, Hawaii 

(.) 

(. ) (. ) (.) 

..~ x 

'. ' . '. , . 

. x .... if· l! .. ~ 

, , .. ". ~ ~ • 

(.) 

(.) 

Samoa 

(.) 

( . ) . , , • . . . . , . . . •• 

South Pole 

F M A M J J A S 0 N D 

1978 

CO 2 mixing ratios are 
Stations Inst. No. Agency Period of Record 

Bismarck, 33 NOAA-ARL 

ND 

Caribou, 34 NOAA-ARL 

ME 

Samoa 42 NOAA-ARL 

Tal lahassee, 58 Fla. State =====,::::::::::::, ==== 

FL Univ. 

Mauna Loa, 63 NOAA-ARL 

HA 

Wallops 72 NOAA-ARL O'= ::::C' ==========> Island, VA 

Barrow, 76 NOAA-ARL 

AK 

Nashville, 79 NOAA-ARL > 

TN 

Amundsen- 80 NOAA-ARL ======= ,-::::=, ==== Scott 

Boulder, 82 NOAA-ARL 

CO 

Wh ite Sands, 86 Dept. of Army > 

NM 

Huancayo, 87 Instituto GeoPeru fisico de Peru 

1965 1970 1975 1980 

Figure 7 .--U. S . Dobson s pectrophotometer station ne twork , 

in c luding cooperative sta tions. 

Du r ing 197 8, t he six continenta l Dob son instrument s t a tions h'ere visi t ed to 

conduct instrument inspections, perform ins trumen t calibration t ests, and train 

observers . No maj or problems were found, but some instrume nt compone nts s howed 

wear from years o f continuo us service. At Samoa and South Pole , Dobson i nstrument optical wedge ca l ibrations were performed but because of the s hortage of 

time and a logistics prob l e m, the instruments we re calibrated with s tandard lamp 

UQ2 rather than compared directly with the world standard Dobson spectrophotome -

ter . (Results of the Bo uld e r 1977 International Intercompa rison of Dobson Ozone 

Spectropho tometers s how that a Dobson instrument ca n be calibrated, by using 

standa rd lamps, to within an accuracy o f ± 0.5 N units , or about ± 1%. The 

Samoa and South Pole instruments had both maintaine d their previ ous calibra -

tions to within ± 1%. ) 

3 . 2.2 Nodernization and Calibration of Dobson Spectrophotometers 

Duri ng 1978 G~I CC personnel continued to participate in the Wl'IO Global Ozone 

Nonitoring a nd Researc h Project t o upgrade the quality of Dobso n spectrophotome -

ters throughout the world. Tab le 8 l ists the instruments that were recondi tioned . 

New elect ronic systems that use miniat ur e so l id-sta t e hi gh-voltage converters, 

mode rn amplifier circuitry, and elec trome c han ical phase-sensitive rectifiers 

"'ere instal l ed in these instruments . After the alignments of opt ical components 

were chec ked and adjusted, the i nstrume nts were calibrated by direct comparison 

with the world sta ndard Dobson i nstrume nt no . 83 . 

26 
Table 8.--Dobson i nstruments modernized and calibrated during 1978 

Location Instrument no. 

exico City, Mexico 98 

Na ta I , Brazil 93 

Le ni ngrad , U. S . S .R. 108 

Manila, Philippines 52 

Boulder , Colo., U.S.A. 38 

Dobson instrument no . 93, now l oca ted at Natal , Brazil, was operated at 

Puerto ~Iontt, Chile, in 1965. The instrument be longs to the United States and 

ha s been loaned indefinitely to the I ns titute de Perquisas, Espaciais at San 

Jose do s Campos, Brazil , where it will be operated dai l y by the Institute at 

Natal. Data from the s t a t ion will be us ed for ground truth information to 

s upport a rocket ozonesond e program being conducted at Natal by NASA, Wallops 

Island, Va. 

Dobso n instrument no. 52 , a s urplus Japanese instrument given to the O, 

is located at Manila, Philippine s , and was put into operation on December 6 , 

1978. It is operated on a routine daily ba sis by the Philippine Atmospheric 

Geop hysica l a nd Astronomi cal Service Administration at the Manila Observatory . 

Dobson instrume nt no . 38 was in operation at Green Bay, Wis., for a number 

of years before observations were termi nated i n 1975. It has bee n modifi ed , 

optically aligned, a nd recalibrated, a nd is now used as a secondary standard 

instrument for total ozone meas urements at Boulder , Co l o . 

3 . 2.3 Data 

Daily 1978 tota l ozone values (applicable to local apparent noon) for all 

stations in the U.S . network have been s ubm itted to and are available from t he 

110rld Ozone Data Center, Atmo spheric Environment Se r v i ce, 4905 Du fferin Street, 

Downsview, Ontario M3H5T4. Table 9 lists mean monthly 1978 t otal ozone amounts 

for t he NOAA observato rie s and cooperative s tations. 

3 . 3 Surface Ozone 

3 . 3 .1 Operations 

At the end of 1978, the Dasibi ozone photometer at the South Pole was 

replaced with a n updated, reca librated version and use of the ECC meter was 

discontinued . Surface ozone mea s ur ements were discontinued at Fritz Peak Obser -

vatory west of Boulder because pollution from the Denver urban area prevented t his 

site from providing data r epresentative of c l ean air at mid latitudes in the 

Nort hern Hemis phere. 

27 
Table 9 .--1978 provisional mean monthly total ozone amounts (mi ll i - atmo-cm) 

Location J'n Feb tla r Ap' Iay Jun J ul Aug Sep Oc t Nov Dec 

Bismarck, N. Dak. 374 386 367 373 369 340 322 313 291 289 305 332 

Caribou, tiaine 378 431 428 412 373 359 349 322 318 317 296 343 

Tutuila Is., Samoa 261 262 262 259 263 267 271 266 271 268 265 268 

Tallahassee, Fla. 291 293 312 307 326 318 325 316 306 288 285 276 

Mauna Loa, lIa\.,:aii 238 234 254 281 284 269 271 264 261 251 256 258 

Barro .... , Alaska 425 426 398 366 317 295 309 307 

Wallops h. , Va . 333 340 342 338 348 33 1 323 308 300 294 278 296 

Nashvi lle. Tenn. 323 332 334 345 360 350 328 321 302 298 282 295 

Boulder, Colo. 322 325 340 337 349 323 315 310 297 283 282 291 

\o.'hite Sand s , N. ~Iex . 287 306 308 314 331 310 308 307 294 288 284 280 

Huancayo, Peru 258 264 264 258 263 266 266 269 269 270 271 260 

Amunds en-Scott, 329 301 276 280 288 288 293 297 369 328 

An t arctica 

3 . 3.2 Data Analysis 

Research on the chemistry of the unpolluted troposphere requires co ntinuous 

moni toring of the surface ozone content of the troposphere . The distribution of 

ozone in c lean air must be studied before a determination ca n be made of whether 

or not the troposphe ri c ozone distribution results from photochemical or transport 

processes, or both . Since the four baseline stations of the GHCC network are 

far removed from maj or local sour ces of ozone producing or destroying contamination, samples taken there represent ozone behavior in the clean troposphere . 

Heasurements of surface ozone have been made by the ECC meter and Dasibi 

ozone photomete r since 1973. Befo re the 1977 Summary Report, data were published 

with the assumption that the instruments \','ere self- calibrating, i.e . , t hat ozone 

amounts could be calcula ted from the basic instrume nt equations. Comparisons 

existed, however, be tween field instruments and ECC meter 001-1, a secondary 

standa r d . During the past year, a Dasibi ultraviolet photometer was referen ced 

to the NBS three me ter pathlength photometer and established as a network sta ndard. 

The sta ndard maintained by NBS agrees closely with UV photometers built by 

severa l U.S . organizations (Wendt et al., 19 79) . 

All meas urements made by the ECC meter or Da sibi ozone meter since 1973 

have been adju sted to the scale represented by the NBS photometer. All surface 

ozone data gathered by GHCC since 1973 and published in previous Summa ry Reports 

are s up erceded by the data publishe d he re. 

In some cases we had difficulty tra c ing the ca libration from the NBS 

photometer back to a field instrument . The NBS standard is accurate to approximate ly ± 3 nanobars (1 nanobar = 1 ppb at 1000 mb) over the range of interest. 

Other instruments used to transfer calibrations and for field operations have 

comparable accuracy. When dealing with ozone leve ls of the order of 5 to 40 

28 
nanobars, an un certainty in the calibration of 3 nanobars in each of at least 

two transfers of calibration (from NBS standard to secondary standard to field 

instrument) becomes important when looking at long-term changes in ozone. 

Surface ozone variation s apparent in data presented here are on three time 

scales: a diurnal cycle, day - to - day changes, and a seasonal cycle. 

The diurnal cycle at Mauna Loa in fig. 8 has been mentioned in previous 

reports and is close ly associated with the mountain wind circulation. The 

larger data base now available ha s s ub stantiated previously observed ozone 

variations. 

At Samoa a diurnal variation (fig. 8) is detectable with a maximum around 

0700 in the morning and a minimum in the afternoon. The caus e of this variation 

has not been determined. A study of the local wind behavior does not reveal any 

important variatio n in wind speed or direction as a function of time of day. 

The monthly mean values of wind speed and direction for each hour of the day 

were investigated and no diurnal cycle was revealed. In addition, a large 

number of individual days on which a diurnal ozone variation appeared were 

checked with the wind observations to see if changing winds mi ght leave the 

ozone samp ling location in st agnant air or air that had a fetch from over vegetate d land areas. 

Although several curves in fig. 8 f or Barrow appear to indicate a possible 

diurnal variation, this is not the case. These variations result from a few 

large day-to-day changes which bias the averages presented in this da ta representation. 

At the South Pole (fig. 8) where the Sun is above the horizon for 6 months 

and below for 6 months, one would not expect any diurnal effects due to solar 

input. The constancy o f the results in fig . 8 suggests that the data are not 

influenced by local pollution, instrument temperature variations, and other 

adverse effects that migh t be related to 24- h work sc hedules . 

I n contrast to the diurnal variation at the GMCC stati ons are measurements 

made at Fritz Peak ( fig. 8). Although this site is not within an urban area , it 

is strongly influenced by pollution from Denver to the southeast. During the 

late spring and summer month s in particular, the diurnal variation shows a 

minimum in the morning and an afternoon maximum typical of polluted environments. 

During winter months there is less s uns hine available, and westerly air flow 

usually prevails, minimizing l oca l ozone production. 

Day-to-Day Variations 

At all GMCC stations the day-to-day variations in surface ozone are pronounced. 

At the South Pole t hese variations are confined primarily to November, December, 

and January . The variations at the South Pole have been attributed to weakening 

of the near-surface t emperatur e inversion during summer months, allowing the 

downward mixing of air from above and advection of air from lower polar latitudes 

(Oltma ns and Komhyr, 1976). Although these summertime flu ctuations are very 

large compared with the nearl y constan t readings obtained during the remaining 

months, the y are relatively small compared with t he va ria t ions seen at the other 

locations (fig. 9). Figure 10 shows an example of these variations where the 

daily values for a month are plotted for each GMCC sta tions and Fritz Peak. 

29 
15 

10 Dec-Jon-Feb 

Dec-Jon-Feb 

9 Samoa (140 SI 

14 

13 

Mauna Lao (19Y NI 

i i'? 

'it 0 Mar-Apr- May .0 

0 

c 

Mar -Apr-May 0 

z 

" i" 19 ~ 

~ Jun-Jul-Aug ~ 18 

'" 

11 

"t 30 

19 

i'? 

0 18 .0 

0 

c 14 0 

z ." 13 Q: 17 

0 

Jun -Jul- Aug l' 

~ 11 

'" d' 16 

'" c Sep- Oct - Nov 0 15 N 

0 

14 

~ 

l' 11 CL 

·2 10 

~ 11 d' 

'" c 11 0 

N 

0 10 

Sep -Oct - Nov 

Annual 13 

19 11~11l-!1~~4:'-"::P+~10~~'1i::1~":±4~~6 ~L8 :L,~O L'1 

AM PM 

15 Local Standard Time 

14 

13 1973-1978 

11'1 1 4 6 8 10 6 8 10 11 

AM PM 

Local Standard Time 

31 f..-~-~~-- _,-<>-~N_av~-~D_eC_-_J-,ayn_-F~e~b __ 

30 Barrow (71 0 N) 

AM PM 

Local Standard Time Local Standard T ime 

30 
5 '" 

"" 0 

" 0 

z 

" i!' 

~ 

'" '" " .t 

"5 

'" 

~ 

" " 0 

N 

0 

36 

40 

38 

36 

34 

31 

Jun-Jul·Aug 

30 

18 -

34 -

31 - Annual 

11 1 

I I 

1 4 6 8 ~ 11 

PM 

Local Siandard Time 

Figure 8 . - -Diurnal variation of surface 

ozone by season and for the year at 

Mauna Loa, Samoa, South Pole, and 

Barrow (p. 30 ), and at Fritz Peak, 

Colo. (p. 31). 

These variations appear t o take place on a sca l e of one to several days. This 

time fra me is s ugges tive of synoptic scale weather events during which air 

ma sses of differing ozone content move over a station or meteorological conditions 

allow enhanced ozone mixing from ozone rich layers above. 

The mo st pronounced day-ta -day changes in surface ozone occur at Barrow 

during the spring when it is not unusual for daily ozone values to fluctuate 

from near zero to 30 to 40 nanobars. The near zero va lues may persist for a 

couple of days . It is not clear where a ir so depleted of ozone originates. 

Seasonal Variation 

Seasonal variation is a marked feature of the surface ozone behavior at the 

GMCC stations (fig. 11) . At the South Pole where day-to-day changes are relatively 

small the most striking feature of the surface ozone record is the annual cycle 

with a range equa l to about 50% of the average annua l concentration. A rather 

s harp minimum occurs in February or flarch a nd a broad maximum from July through 

November (see fig. 9). 

Unlike t he behavior of surface ozone, the total ozone data at high latitudes in the Southern Hemisphere show a broad minimum centered around flarch and 

Apri l a nd a s harp maximum in November f ollowing that in surface ozone by about 

31 
Barrow (71 0 N) 40 

20 c ~ .2 

!! I L!,~,! 0}-~F7it~z~p a~k (4MO"0~N~)--~-----------{ 0 m ~ 40 i ~ Y ~ 60 :;; 

~ ~ I ~ t r I f I I ~ i ~m m~ 

.S 10 1975-78 .S 

~ o'.l:-------------------------------{ 0 .2 

~ 40 Mauna Loa (19.50 N) 60 &1 

1l..30 I~I ~ 

o ~ I I i ~ ~ ~ I 2 .~ ~ ~~ ! '" 1973 -78 E :5 O}---------------------------- --iO => 

o 10 Samoo (I4"S) ~ f y f :g 

Q Q 2 ~19~6-78 I ~ 11--------"'-'~"-"------_{ 0 0 

South Pole (900 S) 

c o a c a a a a 

D 0 

10 1975-78 

0~~f~~A~~M~J-+J-7A-7S-70~~0 0 

Month 

Figure 9.--Averaged monthl y surface 

ozone amounts. Ba rs are plus and 

minu s one standard deviation and 

represent variability within the 

month. 

2 months. This difference in the a nnual cycle s uggests loose co upling between the 

tropospheric and stratospheric ozone distributions at these latitude s. 

At Samoa the maximum i n s urface ozone i n July or August i s s harp with the 

minimum ex t e ndi ng over several months from January to April . Here again the 

s ur face ozone ha s a phasing relationship with total ozone in which the s urface 

ozone maximum occurs earlier by about 2 months. This again could indicate that 

the coupling between ozone in the trop ical troposphere and stratosphe r e of the 

Southern Hemisphere i s relatively weak . 

In high la titudes of the Northern Hemisphere at Barrow the s urface ozone 

annual cycle is out of phase with that in total ozone . In s urface ozone t he 

maximum occur s early in the winter , seve ral month s before the maximum in total 

ozone. The minimum in s urface ozone come s at abou t t he time of maximum in total 

ozone. The month-to -month changes at Barrow are unique . Three relative maxima 

seem to occur in February, June, and November. The se maxima do not appear to be 

an artifact of the averaging process brought about by the maximum shifting from 

month-to-month fr om one year to the next. They s how up regularly each year (see 

fig. 11 ). 

The minimum be twe e n November and Februa ry is a relatively small dip i n 

gene rally high ozone values and occurs during the dark period at Barrow. The 

maximum in June is a small pea k during generally lower values and occurs i n the 

period when the Sun does not set at Ba rrow. 

32 
V> 

5 

.0 

0 

c 

0 

Z 

c 

l" 

~ 

V> 

V> 

l" 

"-

~ ([ 

'" c 

0 

N 

0 

40 Borrow 

lO 

10 

10 

0 

Frilzpeak 

10 -

Apr 77 

10 Mauna Loo 

10 

0 Apr78 

o~ __________________ ~ ______ ~ 

:~j OLLI~~5~JJ~IO~LLLI~5~~~10~LLL1~5~~~lO :~~ ~ 

Day 

Figure lO .--Example of day-to-day variations of surface ozone. 

At auna Loa the maximum comes in the spring, and the ra ther broad minimum 

ex t e nd s from late summe r through the f a ll. Both the ma ximum and minimum i n 

s urfa ce ozone precede those in total ozone . At Mauna Loa this seems to indicate 

tha t a more direc t relations hip e xists be twee n stratospheric ozone and surface 

ozone since the maxima and minima o f each fal l during the same season but that 

other i mportant factors must contri bute to t he timing of the a nnual cycle in 

s ur face ozone. 

3 . 4 Stratospheric Water Vapor 

In mid-1978 GMCC began to develop a program to meas ure regularly the water 

vapor content of the stratosphe re. The program was managed by S. Oltma ns within 

the tlonitoring Trace Gases Group of GtICC, a nd F. Polacek was hire d to prepare 

the instrumentation a nd make the ball oon flights. This prog r am wi ll continue 

33 
40 

lO lO 

10 

c 

~ ~ 40 lOt - Fritzpeok 140;N~ iy(\ l:~ 50.~ ~ ~ lO \.y' - 40 & ~10 I I lOS 

~ lOfMouno, A 119SfZ • R 1M 0, 1\ 1:~ ~ ~ 20 - \PI ~ lvpb&vr l~,( ~ 30 r 

t 10 :i' 0' 10 ~ 

~ 10

t 

Samoa (l4'SI /\ ~ ~ i10 J 

°10 I NVJ \,J I 0~ 0 - _ 0 

South Pole 190'SM ,/'l. . A A. ~ 40 

10 - I"" V ~"'bJ lO 

10 

10 

o 1913 1974 1975 1976 1977 1978 

- 10 

o 

Figure ll.--Mean monthly s urface 

ozone concentrations. 

the long series of stratospheric water vapor measurements made by J. Mastenbrook 

of the Naval Research Laboratory since 1964 (Mastenbrook, 1971, 1973). 

The latter half of the 1978 was spent training, procuring equipment, and 

securing an adeq uate fa cility for making the balloon flights. The balloon-borne 

package consists of the frost point instrument and a valving mechanism that allows 

the balloon to turn around at a pre determined altitude and descend at a controlled 

rate. Since meas urements are made during descent, a major source of contamination is eliminated because the instrument is ahead of the balloon's wake. 

In operation the frost point instrument (see fig. 12) maintains a condensate 

(ice or water) on a polished mirror interposed between an induction heater and a 

heat sink of freely boiling coolant. An optical detection syst em senses the 

scattering of light directed on the mirror and controls the input to the heater 

to keep the size of the condensate essentially constant and thus maintain the 

mirror temperature at the frost point temperature. A thermistor e mb edded in the 

surface of the mirro r senses this temperature which is telemetered as a modulation 

of the sta ndard radiosonde transmission. Periodically the mirror is cleared to 

reform a finer grain condensate at the edge of the condensate spot. 

Previous versio ns of the instrument (Mastenbrook, 1968) were produced by 

flastenbrook; the GHCC instrument will be produced commercially and will contain 

updated electronics, light sources, and sensors . 

Initial plans ca ll for monthly flights from Boulder to be made simultaneously 

with flights near Washington, D.C . , by Mastenbrook . Future plans may include 

two flights a month from Boulder and the eventual establishment of a network of 

several stations. 

34 
Air Temp. 

Thermistor 

Air 

Te mp erature 

BaroSwitch 

Bias 

Phototrans. 

Comparator 

Circuit 

Specular 

Phototrans. 

Thermistor 

Mirror --, 

Condensate 

Heater 

Coils 

LED. Len s 

To Heater 

Clear 

Air Temperature 

Reference 

Modulator 

Timing 

Circuits 

To Heater 

Frost-Point Temp erature 

Tra nsmitter 

Figure 12. --Schema t ic diagram of t he fros t poi nt hygrometer . 

3 . 5 Halocarbo ns and N2 0 

3.5.1 Operations 

Heat 

Sink 

Few changes were made in the halocarbon and nitrous oxide monitoring 

programs during 1978. Data quality for all constituents measured (CCI 3 F, 

CCI 2F2 , and N2 0) remained high, as it has since 1977 after sampling and analysis 

techniques were changed to use of pressurized dual sample flasks and calibration 

of t he chromatograph with refere nce gases. 

To upgrade t he program further, researc h is continuing into a number of 

potential problems . Ambient air rather t han dry air samples are currently 

collected, and analysi s results are presented in terms of dry air usi ng theoretically derived corrections based on measurements of pressure, temperature, and 

35 
relative humidity. IYork is continuing to verify experimen tally that the theoretically dedu ced correc tions are highly reliable. Unc ertainties of up to ± 10% 

may be assoc iated with absolute calibrations of the CC1 3F , CC1 2F2 , and N20 

reference gases currently in us e . Refinements in calibration gas preparation 

are needed to reduce this error to ± 1% or l ess . Tests are being made to assess 

the stability of the reference gases during prolonged storage. CC1 2F2 contamina -

tion, caused by temporary use of pure CC1 2F2 to ca librate a nephelometer at 

Barrow, is being investigated . Other potential problem areas under investi -

gation relate to contamination of sampl e flasks, flask trace gas-wal l effec ts, 

and chromatographi c analysis apparatus nonlinearity characteristics. 

3.5 . 2 Data Analysis 

During the latter part of 1978 past and current dat a were process ed to 

improve their reliability . Statistical and meteo rol ogical data se lection 

criteria were applied to raw data to e l iminate data degraded by sampling and 

analysi s problems. The work include d recalibration of reference gas s tandard s , 

as well as interlaboratory calibration gas intercomparisons. 

Raw and selected data obtained from 1973 through 1978 are being prepared 

for a rchiving at the National Climate Center , Computer Products Branch, Federal 

Building, As heville, NC 28801. The data will also be available in a NOAA 

Tech ni cal Report that will describe the sampling and data selection procedures. 

Linear regression lines fitt ed to the se l ected data are s hown in figs . 13 

and 14. Preliminary data ana lysis results, yielding CC1 3F , CC1 2F2 , and N2 0 mixing 

ratios and mixing ratio growth ra tes , are given i n table 10 . Data for 1977 and 

Table lO.--Sununary of CC l 3F, CC1 2F2 , and N2 measuremenL results 

Trace Date Station ~lixing ralio (95%) S .E. Res. Carr . ixing (95%) S.E. 

Bas gro ... ,th rale growth standa rd eoe ff . ea Lic mixing 

rate dev i ation squa red rat io 

I3R\<,' 13. pptv yr- I ±1.8 3. 8 0.756 165.3 pptv ±O. 9 

Jan N\.,'R 13. I ±1.6 3. 8 0.785 162. I ±O.9 

CCI3F I, ~II.O 1:1. 4 ±1.6 3. 9 0.774 155 .0 ±o 9 1978 StlO 13. 2 ±I .4 3 . 4 0.826 146 5 ±o . 8 

SPO 15 . 4 ±7 .4 12. 8 0.408 146 5'" " ±5 . 

BRW 20 .3 ±5 .4 25 . 7 0.399 11 6. 2 ±6. 5 

CC 13f Jan I, r-ILO 17 .6 ±3 . 7 21 .9 0.469 107 .4 ±4 . 6 19 75 S~IO 17 . 7 ±4. 7 23. 2 O. 432 98 .6 ±6. 7 

ORW 10. I :t8. I 5 .2 0.161 296. 9':'-:'" ±5 . 5 

N\oiR 19. I ±3 . 7 6.6 0.707 285 . 8 ±2 .3 

CC I 2F2 

Jan I, NLO 18. 8 ±3. 7 5.8 0.656 279.9 ±2. 2 1978 S~IO 18. 4 ±3 .3 6.6 O. 655 262.5 ±I . 5 

SPO 20. 8 ±6. 10. 2 O. 652 258.6 ±4.0 

BR .... ' -I .9 ppbv yr- 1 ±I .5 2 .0 0.097 336.0 ppbv t o.S 

Jan N''R 0.6 ±I .7 2 .6 0.009 335 . 8 ±o 9 

N20 I, ~ILO - 1.9 ±I . 4 2. I 0 .109 334 . 4 ±o 8 1978 S~IO 1.3 ±I . 7 2 .3 O. 049 334 . I ±o 9 

SPO -4. 3 ±1.9 3. 3 O. 4 14 335.0 ±I .2 

':"Value used in analysis .... '3S 143.8 pptv derived from obse r va L i OilS made in Jan 1979 and ex trapolated 

Lo Jan I, 1978. 

,"'''Val ue lIs ed .... '3S Dec 3 1, 1978, result of 288.3 pplv derived from linear reg ression line, eXL rapolaLe d 

LO Jan I , 1978. 

36 
0 0 

0 0 , I I N N 

BRW BRW 

0 _CCL3F .~ 0 CCL3F .. ~ '" . .. .... ' .. ." . e.' .... . . ,.- . > 

~g J..' . . ~f;l . .' .. - . - '. . &- ~ . ' . 0._ 

~ 

. · ... ~ " ." M 

M ~ -, · .. " ~O '. - - 0 0 0" O~ 0- . ~ 

0 

~ - - "I 

~ I I , 0 

0 8 0 N N 

NWR MLO 0 CCL3F 0 GCL3F ~ . ~ . . " '" . > .. .:~ >0 

~~ . • . ~. ~o .. •••. I .. .. . o.N &- · . 0._ .. ~. • ~ . .. ~ M , .. . .. · :.:. M ~ ~O 00 .,.. , 0" 0- O~ , . .' .' . 0 

~ "I 

0 

:? 0 

0 0 

0 0 

N N 

MLO SMa 0 CCl3F 0 CCL3F 

~ '" .. , > 

;- ~g ~o 

.' r · . · o.N &- , 0._ · \ ~ ~ ~ .. .[' M · ..... ,. . . M 

~o · ~ 

0 " · . . · 00 · . 0- .. O~ j 

0 0 ~ " (b) 0 

:? 0 

0 1973 ,97<1 1975 

0 I , I I Year N 

SMa 

_CCL3F 0 0 - '" ~ spa CGO SMa MLO NWR BRW 

~g - . • :N &- . . .. -.... 0 160i 

~ 150 

~ · . '. " 1978 '30 - .' . ~ • • 

., 0 " ., - 0- -;. , ... · . '40 § - - 0 ~ 

~- M 

~- ~ 

I I ~ )J 130 

0 l :? 

0 > 

~ ~ 

0.0 > 

spa o.m ~ 285 0. 

0 CGL3F 0. 

~ ~ 275 1978 M 

~ 

1=:g 0 

&- OR 265 

~ 

0- 0" 

'30 

In 

0. 

> 339 337 

~ 0 0. 

0 ~ 

~ 0 

N 335 C 1978 z (a) (c) 

~ 1977 1978 90 60 40 20 0 20 40 60 90 

YEAR S Latitude N 

Figure 13.--Linear regression lines fitted t o (a) selec ted 19 77 and 1978 

CCl 3F data and (b) se lected 1973 to 1977 CC1 3F data; and (c) plots of 

latitudinal distributions of near ground-level CC1 3F, CC1 2F2 , and N2O. 
~ 0 

~ , I I , M 

BRW SRW 

~ :- CCl2F2 - :;: N20 

M 

> 

ii:>1 r- ---; 

>0 

~M ,. ~~ .' .. .. . . N ~ . -,. ~ ,. ~:il ~~ r- - UN Z M 

U 

~~ - 8 M 

8 I I I I I I I I I I :;: N N 

~ 0 

~ M 

NWR NWR 

:;: CCl 2F2 0 N20 ~ 

M M 

> > 0 . ii:>1 <D' . ~M ?- ~M 

... .. N ~ 

~ .:. ... >1 0 

UN 

~:;: .. ~ ,," -.. U 

0 8 N • M 

8 0 

~ 

N N 

~ :;: 

M 

MLO MLO 

Ii; CCL2F2 0 N20 ~ 

M M 

> rO > 0 ~N 

M 1P~ N '. ~ . .. .' ~ .' . 1<0 ~:;: Z~ UN 

U .~ 

0 8 • M N 

8 :;: N N 

~ 0 

:s: 

SMO SMO 

:;: CCL2F2 0 N20 ~ 

M M 

> rO >0 ~N 

~M <D~M ' .. . . ' . N ~ 

~ '. NO >10 _'. ~~ . UN .. ~ 

U 

0 .. 0 

• 0 N M 

8 :;: N N 

~ 0 

~ , I I I , I , M 

SPO SPO 

Ii; CCL2F2 0 _ N20 ~ - M M 

> rO >0 , ~N - ~M ~;:; .. N ~ 

~ .' NO .. 22 ~~ - - UN Z M 

U 

. . ~ .. g - - N 

(a) c (~) I I 8 0 , , , ~ 

N 1977 1978 N 1977 1978 

YEAR YEAR 

Figure 14. - -Linear regression lines fi tted to (a) selec t e d 1977 a nd 1978 

CC l 2F2 da t a a nd (b) se l ected 1977 and 1978 N20 da ta. 
1978 are considered to be of hi gh quality since air samples during this time 

interval were analyzed by using reference calibration gases traceable to R. A. 

Rasmussen standards maintained at the Oregon Graduate Center. Data obtained 

before 1977 are considerably less reliable since calibration gases were not used 

when analyzing samples; rather, reliance was placed on the coulometr i c performance 

of the chromatographic analysis apparatus. 

Results of a preliminary analysis of the CCl 3 F and CCl 2F 2 data are shown in 

table 11. The analysis has yielded best estimate tropospheric residence times of 

86 yr for CCl 3F and 1 13 yr for CCI 2F 2 . Taking into account measurement random 

sta ndard errors, as well as estimated systemati c errors associated with the 

calibration gas mixing ratios, minimum tropospheric residence times for CC1 3 F 

and CCl 2F 2 of 30 and 33 yr, respe ctively, have been determined. Included in 

table 11 is information on global abundances, global mixing ratios, gradients, 

and interhemis pheric exchange parameters derived from the CCl 3 F and CCl 2F 2 

measurement data. 

3.6 Stratospheri c Aerosols 

3.6.1 Mauna Loa Lidar 

Although the lidar performed exceptionally well during the first half of 

1978, problems developed afterward. During spring 1978, t he output etalon on 

the laser was replaced with a 35% dielectric reflector, which boosted power 

output and made adjustment much more stable. We were able to achieve output 

energies 50% greater than the manufacturer's specifications. The laser head was 

t horoughly rejuvenated at this time, and we also began using neutral density 

fi l ters to attenuate the signal so that more accurate tropospheric profiles 

could be obtained. 

Although the laser was operated at very high power levels during swnm er 

1978, the laser output decreased slowly during t he fall, probably because of 

damage to the new output reflector. The field staff did not find damage to the 

mirror during a system inspection, but subtle damage was apparent on closer 

inspection during the following spring, at whi ch time the reflector was repaired. 

From November to January minor problems in the data acquisition system 

prevented computer analysis, and Polaroid photos were taken. 

3.6.2 Barrow Lidar 

The Barrow lidar system is nearly completed. Development of the signal 

processing system was a major task this year. In spring 1978, a new dynode 

chain was designed and fabricated. After testing, it was found that the signals 

were still being distorted by the strong return from the near atmosphere, so we 

tested the NCAR dynode design. The circuit was fabricated during winter 1978 

and seemed satisfactory. It was also discovered that the Biomation transient 

digitizer on the Barrow lidar was more sensitive to overload than the Mauna Loa 

digitizer . This meant that we had to either develop a clipper unit and implement 

a switching amplifier as NCAR had done, or find another solution. During summer 

1978 we tested the NCAR swit ching amplifier, and began fabricating our updated 

version of the NCAR unit. If the unit works well in Alaska, .... 'e will want to 

bui l d one for the Mauna Loa lidar system. 

39 
Table 11.--Sun~ary of CC l 3F and CC1 2F2 data ana l ysis results 

Parameter 

Globa l mixing ratio, X 

N.H . mixing ratio, X 

S.H . mixing ratio, X 

(pptv) 

(pptv) 

(pptv) 

N.H .-S.H. mix. ratio diff. (%) 

Global abundance , A 

N. H. abundance, A 

S.H. abundance, A 

(x10 6 kg) 

(x l0 6 kg ) 

(xl0 6 kg) 

N.H.-S.H . abund.diff. (xl06 kg) 

Release, I(±10%) (xl0 6 kg yr- 1 ) 

~Ieasured atm. 

growth ra te 

Gr ad ient 

200 N- 150 S(pptv per deg . l at.) 

Interhemispheric diffusion 

coeff. K (xl06 m2 s-l ) 

Interhemispheric 

exchange rate, 1 

e 

Res ide nce times; 

r(± 0%) 

Cu nnol d e t al. (1978) 

r(IR + 3%) 

Cunnold et al. ( 1978) 

r(IR + 5%) 

Cunnold et a l. (19 78) 

r(± 0%) 

new method 

T(N - 5%) 

new method 

TUI - 10%) 

new method 

(yr) 

(yr) 

(yr) 

(yr) 

(yr) 

(yr) 

(yr) 

CC l 3 F 

Jan 1, 1978 

153 .4 ± 0.9'" 

159.8 

147.0 

8 .4 

CCl 3F 

Jan 1, 19 75 

102 . 9 ± 3 . 9 

109 . 9 

95 . 9 

13.6 

272.5 ± 2.3 

283 . 8 

261.2 

8.3 

3069.3 ± 18.4 2058.4 ± 78 . 2 4799.5 ± 40.5 

1599 .0 1099 .3 2499 . 4 

1470.3 959 .1 2300 . 1 

128.7 

299 . 7 

13 . 2 ± 0 . 8 

0 . 25 

0 . 5 

1. 2 

39 

30 

86 

37 

30 

140 . 2 

316 . 1 

17.7 ± 2 . 9 

0.26 

0 . 7 

0 .9 

27 

20 

199 . 3 

37 1. 9 

18.7 ± 2.2 

0.51 

0 . 4 

1.5 

10 1 

21 

18 

113 

39 

33 

*Indicated errors in concentrations, abundances, and growth rates are 95% 

confidence interval random standard errors. 

40 
Two new dyes, Rhodamine B and Red 6, were tested with wavelengths of 0 . 62 

~m and 0.695 ~m, respectively, because the signal-ta-noise ratio of the lidar is 

improved at longer wavelengths. Neither dye had a longer lifetime than the dye 

in use, Rhodamine 6G, and Red 6 contaminated the system and degraded performance 

for some time. We c hanged the dye solvent from methanol to ethanol to extend 

dye lifeLime . 

The optical assembly of the lidar was refined this year. We added provisions 

for using narrow-band interference filters to reduce skylight background noise 

during daytime operation . A co llimating lens was added, and filter holders were 

redesigned so that the filters ca n be cha nged quickly. Filter holders for 

neutral density filters were added to optimize daylight operation. Experiments 

were performed to find the ideal view field to reduce the daylight background 

nois e to the lowest possible value. During these tests the provision for easy 

laser alignment designed into this system was very easy to operate with narrow 

fields of view. 

During the development of the lidar system, we took stratospheric data at 

Boulder. Although the data accuracy was not high because of system problems, we 

observed that there were no sharp layers of aerosol caused by the two volcanic 

events during this time. 

This year we purchased additional computer memory to make a total of 16K 

words. This allQl,'ed us to write the lidar control program in FORTRAN at greaL 

savings of time. If the program needs to be modifi ed after field testing, the 

use of FORTRAN makes this very easy . A wavelength tuning prism assembly ,,'as 

a dded to the laser so that narrow-band interference filters can be used. A 

Pol~roid camera and monitor oscilloscope were purchased that will be used to set 

up and monitor the lidar's operation and provide backup data collection capabilities during partial system failure. 

In January 1979 the real-time, multitask FORTRAN program to control the 

lidar and process the data was completed. The overall program is described in 

the 1977 Summary Report. The old program was written in assembly language and 

was therefore difficult to modify. A closed -loop water chiller was installed to 

cool the laser lamp and dye. We will use a 50% antifreeze solution in Barrow to 

avoid freezing . 

3 . 6.3 Data Analysis 

Some data analysis was performed during 1978. A modification in the analysis 

program allows the incorporation of rawinsonde temperature and height data so 

that the Rayleigh backscatter can be calculated more accurately. Although not 

very important at Mauna Loa, it will be important at higher latitudes where the 

temperature profiles depart markedly from a standard atmosphere. Final analysis 

of some older data was begun. The Polaroid photos from 1973 were reanalyzed by 

C. Shilvock. The paper tapes containing data from 1974 to the present were 

loaded onto the disc by H. Crabtree so that final analysis can proceed. J. Harris 

modifi ed the lidar computer program so that the disc can be used as a source. A 

FORTRAN version of the analysis program was written during 1979 to try to streamline the data analysis procedures. 

41 
3.7 Surface Aerosols 

The GMCC surface aerosol mon i toring program for 1978 include d the measurement of condensation nuclei at all sites and integra ted aerosol light sca ttering 

at Barrow, auna Loa, and Samoa. 

Cond ensation nu c lei were measured continuousl y by using G.E. nuclei coun ters, 

whic h had been mod ified to i mprove sensitivity and reliability. A Poll ak photoelectric nu c lei cQunter, located at each site , served as a secondary standard 

and provided routi ne calibration for t he other nu cle i counters on site . 

Four- wave length nephelometers measured integrated aerosol light scattering 

continuously a t the obse rvator i es. These instruments were calibrated eve ry 2 

months by fi lling them with CO 2 gas and ad justing t he instrument outpu t t o the 

known scattering coe ffi cients of CO 2 . An internal calibration chec k was pe rformed 

weekly . 

3.7.1 Barrow 

Pollak counter SN16 was operated routinely at Barrow without probl ems 

throughout 1978. Daily observations provided routine calibration che cks for the 

G.E. counter. Five consecutive Po llak observations were mad e week l y to provide 

for a ca l ibra tion adj ustme nt of the G.E. counter . 

During DOY 108- 160, the Barrow G.E. co un ter was sent to Boulder for c lea ning 

of t he casting and rewiring of the c hassis. Otherwi se, the instrument was down 

only occasionally for mai ntena nce a nd was ope r ational f or 67% of 1978. Ca lib ra -

tions were performe d weekly (only during bac kg round condit ion s) and a routill e 

dai ly check provide d quality control. All data were reco rde d on magnetic tape 

and a ba c kup c hart recorder . 

Four-wavelength nephe lometer SNIOS opera t ed properly throughout most of 

1978. The i nstrument was se nt to Boulder for r epair on DOY 171 a nd returned t o 

Barrow on DOY 216 . The interi or of the i nstrument was clea ned and pain ted , and 

both white ob j ects were pai nted with Eastman white reflec tance coa ting. The 

Barrow nephelometer was opera t ional for 71% of 1978, and a ll data were recorded 

on magnetic tape and a backup chart recorder. 

3 . 7.2 Mauna Loa 

Pollak counter SN13 was operated hourl y during the normal working day 

throughout 1978 with no problems . In addition , five consecutive Pollak observations were made week ly to provide ca libration for the G.E . counter. 

From DOY 236-270 , the Mauna Loa G.E. counter was sent to Boul der for 

repairs a nd the casti ng was cleaned and t he optica l chambe r repainted. The 

Mauna Loa G.E . counter was operational for 82% of 1978. 

The Mau na Loa four-wavelength nephelometer was on line from DOY 31-364 

except for mi nor downtime fo r mai ntenance and calibration. The instrume nt was 

operational for 85% of 1978, and all data were recorded on ma gnetic tap e and a 

backup chart r ecorder. 

42 
3.7.3 Samoa 

Pollak counter SN20 operated routinely at Samoa during 1978 with no problems. 

Daily observations were performed for quality control on the G.E. counter and a 

weekly set of five Pollak observations was made for the calibration of the G.E . 

counter. 

The Samoa G.E. counter operated properly throughout the year, but because 

of numerous station power outages, the data set it produced was equivalent to 

85% of the hours in the yea r. 

The Samoa four-wavelength nephelometer was inoperative from DOY 301-365 and 

was sent to Boulder for repair. Its problems were a clogged inlet port on the 

blower box, causing the blower to overheat and s hut down, and loss of sensitivity in the infrared in the photomultipli er, which required replacement. The 

instrument's interior was cleaned and painted with optical black paint, and the 

two white objects were painted with Eastman white reflectance coating . The 

instrument was returned to Samoa on March 16, 1979. It was operational for 70% 

of 1978, and all data were recorded on magnetic tape and a backup chart recorder. 

3.7.4 South Pole 

Pollak counter SN15 was operated twice daily during clean conditions with 

no problems during 1978. The G.E. counter operated prope rly throughout the 

entir e year and produced good data for 96% of the year. South Pole G.E . coun ter 

data have a ll been scaled by using a linear regression techn ique to bring them 

into agreement with the Pollak counter data . All data were recorded on magnetic 

tape and a backup chart recorde r. 

3.7 . 5 Data Analys i s 

Aerosol data are routinely analyzed by using the procedur e and flow diagram 

pres e nted in last year's annua l report . Briefly, all observer note s and chart 

records are examined immediately when they are received (approximately every 2 

weeks) to ver ify instrument performance and data quality. Once a monthly tape 

is avai l able from the Data Acquisition and Management Group, hourly aerosol data 

are loaded into a disc file in the NOAA CDC 6600 comp uter for ca libration and 

editing. At this time, missing data are filled in from the chart records, data 

qua l ity is evaluated, and a final disc file is constructed of all acceptable 

data. All data through 1978 are available from GMCC in Boulder, Colo. 

3.7.6 Discussion of Selected Data 

Co ndensation nu c l ei and light scattering data from all GMCC stations are 

presented in fig. 15. Mo nthly geometric means of a ll data are plotted for 

Barrow, Samoa, and South Pole. Monthly means of 0100-0700 LST Mauna Loa data 

were used to avoid contamination from the well-known daytime upslope wind . The 

Barrow !igh£ scattering data suggest an annu~l cycle with winter values greater 

than 10 5 m 1 and summer values as low as 10 6 m 1. However, Aitken nuclei data 

at Barrow s how a biannual cycle with maxima in spring and late summer. To 

reveal more clearly the annual cycles, departures from the annual mean by month 

of l ight scattering (so l id line) and condensation nucl ei (dashed line) are given 

in fig. 16. 

The Mauna Loa light scattering data in fig . 15 suggest an annual cycle with 

a maximum in late spring and minimum during the winter. Howeve r, no obvious 

43 
~, ',[ § 

'1l, llllllllilllllliillljllllll 

~ : 1 

V ""'"," ~. : 

III' ,I,!!,',I. 1I,II,!!.I!",!I,!!!!I!!! II I!! III I"I!!I.!!.!1 

1914 191; 1976 1971 1978 

Figure 15.--Light scattering (b ) and 

Aitken nucl ei (N) data for al!PGMCC 

stations . Barrow and Mauna Loa 

light scattering data s how four 

wavelengths in order 450, 550, 700, 

and 850 nm whereas Samoa data are 

in order 450, 850, 700, and 550 nm. 

cycle is present in the Mauna Loa Aitken nuclei data. Departures from the 

annual means by month for Mauna Loa light scattering and condensation nuclei 

data are shown in fig . 17 to reveal annual cycles. The annual cycle in light 

scattering data with a maximum in April-Nay and a small secondary peak i n 

September shows up strongly although there is no apparent annual trend in the 

Aitken nuclei data. Because there are 5 full years of data from Nauna Loa, we 

can take departures from the mean for each year and then ca lculate a mean and 

standard devia ti on for each month of the year. 

Samoa light scattering and condensation nuclei data 

represent a marine aerosol and exhibit no obvious annual 

shown in 

cycles. 

fig. 15 clearly 

The departures 

" o 

~ 

0_05 

- 1.0 '--_--L---'-~_'__Ll/ __ ____'_'__-L---' 

J FMAMJ A SON 0 

Figure 16 . --Departure s from the mean 

44 

by month of light scattering (solid 

line) and Aitken nuclei (dashed line) 

data for Barrow. Geometric mea ns are 

used so that the ordinate is expressed in orders of magnitude. 
c:.> +0.5 ~ 

" i' 

~ 

• 

~ 0 r-~~~~----+-~~~~~~-r-4--l 

0; 

u 

o --0.5 

J MAMJJASOND 

0 

~ 

~ 

i' 

~ 

• " '0 

0; 

"C 

0 

+ \.0 

+0.5 

0 

- 0.5 

- \.O 

J F M A M A S 0 N 0 

Figure 17.--Departures from the annual mean by month of SSO-nm wavelength light 

scattering (left) and Aitken nuclei (right) data for Mauna Loa. Departures 

from the mean were determined for each year, and then a mean (middle line) and 

standard deviation (upper and lower lines) were calculated for each month. 

from the annual mean by month of light scattering and Aitken nuclei shown in 

fig. 18 further confirm the absence of any annual cycles . 

The well-known annual cycle in Aitken nuclei at South Pole shows up strongly 

in fig. IS , and its repeatability is apparent from fig. 19, which gives departures 

from the annual mean by month alo ng with the standard deviati ons by month for 

the 5 years of data. The annual cycles (or lack of them) at the four stations are 

disclIsspn in more detail by Bodhaine (1979). 

Figure 20 s hows monthly geometric mea ns of light scattering at Barrow for 

each hour of the day . Time of day is given in GMT. The magnitude of the light 

scattering is highest during early spring and lowest during summer. For all 

+ 1.0 ,--.-,--,---,---,--,--,--,---,--,----,--, 

0 +0.5 ~ 

~ .g, 

• " 0 

'0 , 

" 0 

~ 

0 - 0.5 

- 1.0 

J F M A M J A S 0 N 0 

Figure 18.--Departures from the mea n by 

month of light scattering (solid 

line) and Aitken nuclei (dashed line) 

da ta for Samoa. 

45 

0; 

"C 

0_0 .

5 

_ 1.0 L..L....L---' ____ ..L-'----' __ 1--'--~ __ L....J 

F M A M J A SON 0 

Figure 19.--Departures from the annual 

mean by month of Aitken nuclei at 

South Pole . Departure s from the mean 

were determined for each year a nd 

then mean (middle line) and sta ndard 

deviations (upper and lower lines) 

were ca l culated for each month . 
========:::::::-

I 

F.b 

6 

~J J -6 

i~ 5~ ==---- -

-6 

s.,~_5 ~~~~~==~~~ 6 

~~.--j: 

I I 

6 8 10 12 14 16 18 20 22 24 

TIme of Day (GMT! 

Figure 20 _--Monthly geometri c means for 

each hour of the day for the Barrow 

nephelometer in 1978. The fo ur chan -

nels of light scattering data are in 

order 450, 550, 700, and 850 rum . 

-5~ ----

-5 1-6 -

.,. ~~J" ~ 

~====~' 

~ J. -6~ ~~1 

J. 

~~--=;=~-. ti,' o 2 4 6 8 10 12 14 16 18 20 22 24 

T,me 01 O~y(GMTI 

Figure 21. --Monthly geometric means for 

each hour of the day for the Mauna 

Loa nephelometer in 1978. The four 

channels of light scattering data are 

in order 450, 550, 700, and 850 nm . 

months , light scattering data are greatest a t 450 run and de crease in the order 

550, 700, and 850 rum. However, spacing of the four channels indicates a t e nden cy 

towards larger aeroso l s in January, August, and September, and s mall aerosols in 

June. Furthermore, a small diurnal cyc le is present, apparently r elated to the 

length of daylight at the Barrow stations. This effect is seen most clearly in 

t he data for ~larch, August , a nd September, and suggests slightly higher light 

scattering values during daylight hours. 

Figure 21 shows monthly geometric means of light sca ttering at MLO for each 

hour of the day. Note that time-of-day is given as GMT rather than LST as in 

46 
'~ I I 

'~I 

., '''I 

I I.'.' 

... . , A,,} 

~ ., 

Mav 

., J 

, j J 

! J: ! 

T ., 

UI 

., 

A.'J: 

l~' Figure 22. --~lonthly geometric means for ., each hour of the day for the Samoa 

'J nephelometer in 1978. The four channels of light scattering data are 

I , I order 450, 850, 700, and 550 nm. 0 6 8 .0 " " " " 20 22 

T,me 01 Day (GMT! " 

the previous summary reports. For Mauna Loa, LST = GMT-lO. The data show the 

same general features as similar data given in previous G~lCC summary reports. 

For example, the daytime upslope wind effect shows up clearly during most 

months and the magnitude of the nighttime data is highe st in early s ummer and 

lowest in winter. However, it s hould be noted that, in general, the light 

scattering values are higher in 1978 than in previous years and show a lesspronounced upsl ope wind effect. In particular, the December 1978 data, unlike 

previous years, show very little diurnal effect. 

in 

Samoa light sca ttering data continue to show no obvious long-term trends. To 

examine the data for diurnal trends, monthly geometric mean s of light scattering 

for each hour of the day were calculated similarly to those for Mauna Loa and are 

presented in fig . 22 . Although the magnitude of light scattering varies somewhat 

from month to month, no trend and no apparent diurnal effect are obvious in any of 

the months. For most months light scattering is greatest for the 450-nm wavelength 

and decreases in the order 850, 700, and 500 nm . The light scattering values at 

450 a nd 850 nm are usually nearly equal, and sometimes the 850-om dat a are greater 

than the 450-nm data . As discussed in GMCC Summary Report 1977, a12 is always 

positive wherea s 023 and 034 are always negative ) suggesting a narrow aerosol size 

distribution for the Samoa marine aerosol. 

47 
z 

C> 

o 

...J 

5+----L--~----~---L--~----L---~---L----L---~---L __ _+5 

4 4 

3 3 

2 2 

+---.---_r--~----._--,_--._--_r--_.----r_--,_--._--_+ O 

Jan Feb Mar Apr May Jun Jui Aug Sep Oct Nov Dec 

Month Of The Year 1978 

Figure 23 .--Aitken nuc l e i data for South Pol e in 1978 . The so lid line s hows 

hourly means o f sca l ed co ntinuous conden sa tion nucl ei data whereas the 

s quares show ind ividu a l Pol la k counte r observations. 

z 

C> 

o 

...J 

Conde nsati on nuc l e i data for the South Po l e have a ll been processed and are 

avai l able in final edited f o rm for 19 74- 1978. All automatic condensa tion nuclei 

data ha ve been scaled acco rding to a linea r regression technique for best agre e -

ment with the daily Pollak co unter ca l ibra tion points. Figure 23 presents all 

au t omatic conde nsa ti on nu clei da ta (solid) by hour and all Pollak counter data 

(squares) for the year 1978. Monthly mea ns of condensation nuclei concentra ti ons 

for both t he G.E . counter a nd t he Pollak co unter are gi ven in table 12. 

Table 12 .--Monthly means of condens ation nucl e i concentration (cm- 3 ) 

a t South Pole in 1978 

Counter J F M A M J J A S 0 N D 

Pollak 111 166 84 29 17 6 8 8 24 70 131 120 

G.E. 103 168 92 31 18 7 8 7 21 77 151 113 

48 
3.B Solar Radiation Measurements 

The fo ur GMCC baseline stati ons co ntinued to r eco rd solar irradiance data 

with t he basic instrument set established in 19 75 -76. The instr ume nt set inc ludes 

f our Eppley global pyranometers with quartz, GG22, DGI, and RGB filter domes , 

Eppley UV pyranometers (excluding Samoa), and Eppley normal i nci dence pyrheliometers (NIP) for meas ureme nt of direct solar irradiance (ex cluding Barrow). 

Measurements are made continuously with these instruments. Data are arc hive d as 

2-min integrals i n kJ m- 2 on the absolute radiation scale. 

The four G~ICC observatories are a lso co llecting discrete me as uremen t s of 

direc t solar irradiance with Eppley NIP 's. Measurements are made through a 

quartz window as well as DGI, RG2 , and RGB Schott glass filters. 

3 .B.I Instrument Calibrations 

Fie l d instruments are calibrated at l east once a year by comparison with 

wor ki ng standard instruments at the GMCC offices in Boulder. Table 13 s hows the 

res ults of intercomparisons compl e t ed in 1977 and 197B. The mea surements of the 

filtered instruments are also compared to the quartz standard meas ureme n ts. The 

ratio of the measurements fr om the filtered pyra nometers t o those from the 

s tandard quartz instrument i s determined and compared with theore tical calculations . Year-to-year changes in the ratios indicate possible dome degrada t ion . 

Add i tiona l tests are performed on the NIP Schott glass filters by comparing them 

with a standard filter set. Filter factors are determined after each intercomparison period a nd checked with the res ul ts of previous tests . The results i n 

table 13 imply tha t the filters have r emained stabl e since their initial i nsta llation. The exception is SMD where the pyranome ter filter domes have degrad ed , 

prob ably because o f t he tropical enviro nment. 

Sta t ion Date 

Pyranometer comparisons 

~ILO 1/26-1 /31/17 

MLO 6/19-7/11/18 

BRW 5/2- 5/6/77 

S~IO 7/19- 8/6/78 

SPO 1/7-1/9/77 

SPO 1/1-1/10/78 

~1 .0 6/19-7/11/78 

Pyrheliometer comparisons 

flLO 11/22-11/28/77 

HLO 6/30-7/11/78 

BRW 2/2-2/4/77 

BRW 5/2- 5/5/77 

BLD 10/1-10/2/77 

BLD 2/2/78 

SHO 1/6-1/8/77 

SMO 1/5-1/6/78 

S~ 0 7/19-8/9/78 

SPO 12/19- 12/30/78 

HLO 11/22 - 11/28/77 

HLO 7/5 - 7/11/78 

SPO 12/19-12/30/78 

Std. inst. 

se rial no. 

10 155 

12617 

10155 

12617 

12617 

12617 

126 17 

13909 

13909 

13911 

13909 

13909 

13911 

13909 

13909 

13909 

13911 

13909 

13909 

13911 

Table 13.--1977-1978 field Instrument calibration tests 

Cal. const. Test inst. 

mV mW- 1 cm- z serial no. 

0.0725 12616 

0.0810 12616 

0.0725 12263 

0.0810 12273 

0.0810 12271 

0.08 10 12271 

0.08 10 12560 

0.0774 13910 

0.0774 13910 

0.0856 13913 

0.0774 13913 

0.0774 13911 

0.0856 13913 

0.0774 13914 

0.0774 13914 

0.0774 1391t. 

0.0856 13912 

0.0774 2119 

0.077t. 2119 

0.0856 2968 

49 

Cal. const . mV m ... ,-I em 2 

0.0794 

0 . 0794 

0 . 99 19 

0.0927 

0.1072 

0.1072 

0 .0970 

0.0825 

0.0825 

0.0826 

0.0826 

0.0826 

0.0826 

0.0829 

0.0829 

0.0829 

0.0815 

0.0295 

0.0295 

0.0295 

Response 

std . /test 

1.0035 

1. 0041 

0.9919 

1.0100 

0.9951 

0.9961 

0.9864 

1. 0071 

1.0097 

0 . 9845 

1.0039 

1. 0092 

0.9848 

1.0110 

1.0123 

1.0075 

0.9978 

0.9998 

1.0079 

1.0706 

Difference 

m 

-0.35 

-0.41 

0.81 

-1.00 

0 .49 

0.39 

1.36 

-0.71 

-0.97 

I. 55 

-0.39 

0.92 

1. 52 

-1.10 

-I .23 

- 0.75 

0.22 

0.02 

-0.21 

-7.06 

fi Iter factors 

OG1 RG2 RG8 

1.095 1.093 1.103 

1. 108 1.096 1.107 

1. 10' 1.110 I. 111 

1.106 I. 111 I. 111 

.095 1.105 1.100 

.098 1.103 1.100 

1.095 1. 100 1.104 

1.09t. 1 .098 1.122 
SOL AR IRRAO' .... tlcE ... r S"RROIr> D"T£ : 79/: 15 SOL AR lRR"OIAllCE AT BARRO',,' DATE : 7 8/: 16 

150 150 

100 100 

" " 

E E 

-, -, 

"'" "'" 

50 50 

o 6 12 18 24 o 6 12 18 24 

True Solar Time True Solar Time 

Figure 24.--(left) Clear day at BRW when pyranometer domes remained unobstructed 

by ice. Curves from top to bottom: calculated ex traterrestrial radiation, 

quartz, GG22, OG l, RG8, and UV pyranometers. (right) Cl ear day at BRW when 

ice buildup occurred on quartz and GG22 pyranometer domes. Domes were freed 

of i ce at about 0830 TST, causing a s harp decre ase in the energy seen by the 

sensors. 

3 . 8.2 Field Site Activities 

South Pole and Barrow 

The major problem at the South Pole and Barrow is ice crystal buildup on 

the pyranometer domes . Figure 24 (left) s hows a c lear day at Barrow (April 25, 

1978) when the domes remained ice free. On the following day (April 26, 19 78, 

fig. 24, right) a thin coating of i ce was observed on the quartz and GG22 pyranometer domes. In this case the ice magnified the energy viewed by the sensor. 

The irradia nce as seen by the sensor ma y be intensified or decreased, depending 

on the th;ckness or distribution of the ice buildup on the dome. Incidences of 

ice were identified and removed from the archived data set. 

On November 17, 1977, new ring blowers we re installed on the quartz and 

GG22 pyranometers at the Pole to prevent ice buildup on the domes. The ring 

blowers clamp to the outer perimeter of the pyranometer radiation shield . 

Warmed air is pumped to the ring blower through insulated pla stic tubing a nd 

forced out small holes in the ring . This system replaced an old blower system 

whi ch forced warm air up next to the dome through a metal ring attac hed undernea th the pyranometer radiation shield. No i mprovement was observe d with the 

new ring air blowers although the new blower system was installed primarily to 

improve the efficiency of keeping the domes ice free and to eliminate the possibility of data contaminati on caused by artific ial he ating of the instrument body 

by the old blowe r system. Since the new blower syst em proved t o be less effective a nd preliminary tests of the old system did not indicate data co ntamination, the old system was reinstalled on December 21, 1977. 

50 
Tests of the blower systems at the South Pole and Barrow were conducted 

throughout 19 78 , and the systems were modified to improve their efficiency. 

Simi lar tests were made at the Boulder facility during the winter months. 

Although final results of the tests have not been completed, preliminary results 

indicate that the old blower system does not significantly affect the pyranometer 

output. None of the systems tested has been 100% effective . 

Solar radiation data at the South Pole were contaminated for short periods 

of time on a daily basis by shadi ng from GMCC and University of Maryland air 

sampling stacks. Shading occurred between 0800-1000 CUT for the pyranometers 

and 1000-1100 CUT for the NIP. Actual shading time for an individua l day 

lasted only a few minute s within these time intervals. The s haded periods were 

identified and removed from the archived data set. 

Nauna Loa 

The solar radiation program ran smoothly during the year. A new chart 

recorder replaced a n old Honeywell recorder used for NIP observations since 

1958. 

Several s hading devi ces for continuous measurement of diffuse radiation 

were tested at LO during the year. All t he devices proved to be unsatisfactory 

because of their design . In November an Eppley shading disc was installed and 

operated well for the remainder of the year . 

The MLO Eppley UV pyranometer (10232) was returned to Eppley on October 25 

for repair and reca libra tion . It was pla ced ba ck i n service on November 27. 

Tests at Eppley s howed tha t the narrow bandpass fil t er had deteriorated and 

sensitivi ty had decreased by nearly 74%. A new filter was installed in the 

instrument and a new calibration factor established. 

The 13-channel radiometer was brought back on line in December 1978 . The 

i nstrument 's output wi ll be analyzed to determine its relative accuracy, and 

some modifi cation may be under t aken in 1979. An eva luation of the instrument as 

a monitoring tool is continuing. 

Samoa 

In 1977, deterioration of the RG8 and OGI pyranometer domes caused glass 

discoloration a nd a degradation of 5% or more in the observed irradiance. The 

exact cause of the dome deterioration is unknown. The OGI and RG8 domes were 

.eplaced in May 1977, but by May 19 78 they had to be replaced again . Attempts 

to solve th is problem are continuing. 

Data 

In fig. 25 3 years of normal incidence irradiance data for the South Pole are 

plotted for "clear" days. The solid line envelops the upper range of the measurements. The wide scatter of points (lower values) is the result of measurements 

taken through ice crystal precipitation periods or very thin cirrus clouds. Note 

the va lues obtained in summer reach ~78% of the extraterrestrial va lue. 

Plots of the daily integrals of horizontal incidence irradiance from quartz 

filter pyranometer for Barrow and Samoa (fig. 26) show the annual variation in 

51 
N 

E 

"-" 

~ 

E 

'" " c 

"C '" 

'" ~ 

~ 

E 

;; 

• "3 

~ 

~ 

~ 

;; "

c 

w 

120nnTTTTrrnnTTrrnn"TTrn"TTTTrnnnTTrrrnnnTTTTrn"TTrrrnnnTTTTrn" 

110 

90 

80 

70 

60 

50 

40 

30 

20 

10 

0 

Jan Feb Mar Apr 

Normal Incidence Irradiance 

South Pole - Antarctica 

1977 - 78 - 79 

May Jun Ju l 

.' 

.' • '0' 

..... : ... :. 

.":J ' 

'. 

Nov Dec 

Figure 2S.--1977-78-79 normal incidence solar irradiancc measurements take n at 

SPO during clear sky, transparent cirrus and ice crystal precipitation 

periods. The solid line envelops upper limits of measured irradiances 

over the 3-yr period. 

Barrow 1977 Samoa 1977 

" " " Daily Integrals of a and ETR Oaily Integrals of a and ETR 

" ~ 

§ 

\i 

8 

" g 

8 

.: "

8 " 

" 

,,~~~~~~~~-l~ __ ~ 

o 30 60 90 120 150 180 210 240 270 300 330 360 

,,

o 30 

~~~~~~~~~~

60 90 120 150 180 210 240 270 300 330 

~ 

360 

Day 0 1 Year Day of Year 

Figure 26.--Daily integrals of solar irradiances show the annual variation at 

Barrow (left) and Samoa (right) . All days (clouds and clear) are included 

in the data . The extra-terrestrial solar irradiance on a horizontal surface 

at the top of the atmosphere for each station is shown by the upper curve . 

52 
' 0 

0.9 

08 

0.' 

O. 

05 

O' 

0.3 

0' 

0.' 

Barrow 1977 

Daily Values of O/ETR , 0 

09 

08 

0.' 

O. 

05 

O' 

03 

0' 

0' 

Samoa 1977 

Daily Values of Q/ETR 

, 0.0 0'----3:":0-."'0,---:90:-.,.""0:-'-':50=-'::80=-""::0:-:'-".0::-''''''0 --::300C:--:3"30::-3=60=--' Day of Year 

OO'----L_-"-~_~~~~ __ ~~~'----:-:::-:L-~~ 

o 30 60 90 120 150 180 210 240 270 300 330 360 

Dayol Year 

. . (quartz pyranometer irradiance) f Figure 27 . --Atmospheric tranSITI1SS10n ETR or 

Barrow ( l eft) a nd Samoa (right) are plotted for day of year . Samoa 

s hows no obvious annual cycle whereas Barrow has a springtime maximum. 

solar irradiance. 

horizontal global 

The solid line plotted shows the extraterrestrial value of 

irradiance available at th e two site s. 

A simpl e measure of atmospheric transmission is plotted throughout the year 

for Barrow (fig. 27 , left) a nd Samoa (fig. 27, right). Note that for Samoa the 

transmission shows no c hange throughout the year. Other than dips during cloudy 

periods the upper values remain constant at .70% for the year. A definite 

annual trend in transmission is observed for Barrow with a maximum in spring 

wh e n cloudine ss is at a minimum and the ice off the coast has not yet broken up. 

Once the ice breaks in May and June and moistur e is available, cloudiness increa ses 

and transmission decreases. This decrease in tra nsmission caused by cloudiness 

is prevalent for the rest of the daylight period in Barrow. It is interesting 

to note that the clearest sky conditions occur in Barrow when the Arctic haze 

phenomenon is at its peak. Consequently, the Arctic haze impact on atmo s pheri c 

transmission in e arly spring may be signifi cant under the c l ear-s ky conditions 

tha t prevail during this period in Barrow . 

3.9 Meteorological Measurements 

3.9.1 Barrow Climatology 

The GMCC Barrow Observatory, located on tundra between two saltwat e r 

marshes, is about 7 km from Point BaHo\'. The wind is mainly determined by 

large-scale weather systems, since no significant topographic barriers are found 

within a 300 - km radius of the observa tory. Between stormy periods, when the 

winds are westerly , the local winds result from the outflow from the polar 

anticyc lone, which produces a persistant, easterly wind at the surface. Barrow's 

radiation climate is strongly influenced by the low-stratus cloud layer that 

forms in lay and persists throughout most of the summeL The coastal cloud 

53 
N 

BARROW 1978 

- <-!oms' 

-S~U 'Oms ' 

O ">10ms' 

06°. Calm s 

Figure 28 .--Distribution of wind direction and s peed 

for Barrow. Units are percent occurrence for the 

year (1978). lYind speed is presented as a function 

of direction in three classes : less than 5 m 5- 1 , 

5 to less than 10 m 5- 1 , and equal to or greater 

tha n 10 III S - 1 . 

layer form s when incoming solar radiation in spring and summer is increasing at 

the same time that extensive leads in the ice pack open along the coast . On an 

average, only 7 days a month during the sunun er have clear or partly clonrly conditions. However, during the winter and early spring, clear and partly cloudy skies 

dominate. 

The distributions of the wind direction and speed are s hown in fig. 28. For 

almost 60% of the hours in 1978 the wind was from an easterly direction, within 

the sector bounded by 30 degrees to 120 degrees. The highest percentage of 

stronger winds a l so occurred in this sector. Calm conditions, when average wind 

speeds were less than 0.5 m s-1 , were observed only 0.6% of the time. As in 

previous years east-northeasterly winds predominated through most of the year 

(table 14). The maximum hourly average wind speed observed during the year was 

18 m s-l from an east-northe asterly direction. 

Examination of the s ucce ssive differences in the monthly average values of 

wind s pe ed and temperature clearly indicates that two distinct seasons occurred 

with brief transition periods in April-May and October-November. The surface 

,,,inds were lighter during the summer months. The average winter temperature was 

about - 22°C, whereas in the short summer season the average temperature was only 

a few degrees above zero. The minimum hourly-average temperature observed in 

1978 was -44°C in December. On the average, the wind speed observed at the GMCC 

Observatory was about 0.5 m s-1 higher, and the temperatures about O.soC cooler 

than those observed in Barrow village (~.S, 1978). 

3 .9. 2 Mauna Loa Climatology 

In the absence of a strong pressure gradient, the met eoro logi ca l conditions 

at MLO are controlled by the diurnal heating and coo ling of the surface of the 

54 
Table 14. --19 78 Barro .... · Obse rvat o ry monlhly cl i mate summa ry 

J ,n Feb Hoc Apc ~Ia y Jun Jul Au g Sep Oc t Nov De c 

Preva i 1 ing I.'i nd ENE ENE NE E~'"E E E E E E NE E E 

directi ons 

Avera ge .... 'ind 6 9 5. 5.1 6 . 1 5. 5.1 5.0 5 0 5.4 5. 6.6 6 3 

speed (m s - I) 

Maximum I.'ind 16 12 14 13 11 13 13 12 14 18 17 15 

speed"" (m s - I) 

Directio n o f max . 90 102 57 106 126 80 266 11 7 53 69 87 98 .... ·i11(I·; .. (deg.) 

Average slati on 1016 .4 1011.1 1019.8 101 7 . 2 10 19 .4 1011 . 2 l Oll . 8 1010 . 7 1006 9 1013. 1009 . 0 1008 5 

press ure (mb ) 

~Iaximum pressure'~ 104 2 1032 1037 1032 1027 101 9 10 19 1022 1025 1013 104 1 1032 

(mb ) 

~linimllm pre ssure'" 996 988 1004 1003 1006 1000 1000 992 988 993 979 985 

(mb ) 

Average air - 2 1 . 6 -26.4 - 24 . 1 -17 . I 9 6 0 8 2 8 1. 8 .7 -1 4. I -15 3 - 25 . 

temperature ( 0C) 

~Iax imum t e mperature"" -9 -12 0 0 7 17 16 13 - 3 0 - 8 

(OC) 

tlinimum tempe rature"" - 34 -4 2 - 37 - 32 - 17 -6 - 2 -3 -1 0 -24 - 28 -44 

(0C) 

,'''Maximum and minimum va l ues '" hourly ave rages. 

mo un tain. At the altitude of t he observatory, 3.4 km, the day is relatively 

evenly divide d between two flow regimes, nocturnal downslope wind from the south 

a nd an upslope flow during daytime hours from the north. The wind rose in fig . 29 

s hows t he predominance of winds from the south-southeaste rly and southwe sterly 

di rections. The relatively large proportion of stronger winds, > 10 m S-I, from 

t hese direc t ions is the result of gradient wind flow from s ynoptIc conditions tha t 

s uppl eme n t the downs l op e wi nds. Wi n ds from the northerly direction are generally 

light and variable. Calm conditions occur on about 1.8% of the hour s during the 

year . Since a northerly wind is an upslope, daytime condition, the plot of wind 

speed as a f un ction of time-of-day shows slightly lower wind speeds in day light 

ho u rs (Peterson , 1978, fig. 28). Wind speed minimums occur when the shift from 

o ne regime to t he other occurs at 0800-0900 and at 1800 LST. Average daytime 

temperatures at MLO are about l l oe, and average nighttime temperatur e s are about 

4°C . 

Monthly variations in the meteorological parameters are small compared to 

the diurnal variations . Westerly winds are generally more common in the winter 

mo nths t han at other t imes when southerly wind prevails (table 15) . The average 

wind speed for the year is 5.4 m s-l, with the maximum speed of 19 m s-1 from a 

di r ection of 256 degrees. The average station pressure is 680.9 mb, with an 

average range of 8 mb between maximum and minimum values. Both the ave rage and 

t he separa t ion between maximum and minimum vary little through the year. The 

a ir temperature shows a small annual cycle with an amplitude of about 3°C. 

Max imum and minimum values show this cycle as well. 

55 
MAUNA LOA 1978 

_ 5m5 1 

_S" U< ,Oms- 1 

O ;a 'Oms- 1 

18%Cillm 

Prevailing .... ind 

directions 

Average .. dnd 

speed (m , ' ) 

tlaximum ",'ind 

speed'''' (m s - 1 ) 

Direction of max. 

\,,'1I1d", (deg. ) 

Average station 

pressure (mb) 

tlax imum pressure"; 

(mb ) 

tl i 11 imum press ure;; 

(mb) 

Average air 

temperature (Oe) 

}Iaximum temperatHre'': 

(0e) 

Minimum temperature'" 

(DC) 

N 

s 

Table 

J.n 

5>' 

4.7 

13 

255 

681.7 

685 

676 

5.2 

J4 

- 2 

"'-}Iax imlim and minimum values arc 

15.--1978 Nauna Loa Observatory 

feb tla r Ap' M.y 

WS\o,' SSE S5E SSE 

8.0 8.8 4.8 4 . ' 

13 19 12 15 

273 256 138 150 

680.7 680. I 680.3 68 1.2 

685 684 685 685 

673 674 677 677 

4.7 5. I 4.8 6 .4 

J4 J4 J4 16 

- 3 -4 -2 0 

hou rly averages. 

56 

Figure 29 . --As in fi g . 28 , except 

for Na una Loa Observatory. 

monthly c 1 im3 te sUlnrna ry 

JUIl Jul Aug 5ep 00l Nov 

SSE 5 SSE 5 5 5W 

4.6 5 . I 3.' 4.2 3.6 5.2 

13 17 13 12 , 18 

163 161 185 170 162 230 

681.3 681 . 3 681.7 681.5 681.0 679.7 

684 685 684 684 684 683 

678 677 676 67. 677 675 

7.2 7. J 7.6 7.4 6.8 4.3 

16 15 16 17 16 II 

- I 0 - 2 

Dec 

5 

6.4 

17 

164 

680. I 

684 

674 

4. I 

13 

- 4 
3 . 9.3 South Pole Climatology 

The surface winds from a grid-northeasterly direction are the most persistent 

feature of the climate at the South Pole. These inversion winds are relatively 

steady compared to the more intermittent katabatic winds common to drainage 

situations . The prevailing wind is from the north-northeast, a direction approximately 50 degrees right of the direction of the Antarctic dome. The station is 

located on the Amundsen-Scott plateau (elevation 2.85 km) which has little 

topographic change within a 100-km radius of the station. The plateau is a 

depression near the western edge of the main high ridge of East Antarctica. The 

highe st point on the plateau is about 900 km east-northeast of the Pole at an 

elevation of about 4 km . 

Figure 30 shows the distribution of the wind direction and speed for 1978 in 

polar coordinates. As in previous years the most persistent direction is from 

the north-northeast occurring more than 20% of the time. On 85% of the hours 

during year the wind blows from the northeastern quadrant. The stronger winds 

are from the north and tend to occur more frequently during the Austral winter 

months (see table 16). The average wind speed for the year was 5 . 2 III s-1 The 

maximwn wind speed observed during the year was only 13 m s-1 Calm conditions 

occurred for only 0.1% of the hours in 1978. 

The change in the monthly average temperature shows a rapid transition from 

summer to winter, which is typical of the Arctic region . The average temperature 

remains below -50°C for 8 months of the year. The average temperature for 1978 

was -48.4°C. The maximum hourly average temperature was -13°C; the minimum was 

-77°C. 

SOUTH POLE :.97:.:8:-t-__ 

\ 

, 

I 

S 

57 

Figure 30.--As in fig. 28, except 

for South Pole Observatory . 
Table 16.--1978 South Pole Observatory monthly cl imate sunvnary 

Jan Feb Mac Apc ~Iay Jun J"1 A". Sep Oct Nov Deo 

Prevailing ~'ind ENE NNE NE N N NNE ENE NNE ENE N NNE N 

directions 

Average I.·ind 3 . I 5. I 5.7 5 8 6 0 5. I 5 . 5.7 5 . 3 5.5 5 .0 4.8 

speed (m s - I) 

~Iaximum I.·ind 8 9 II II II !O 10 II 13 12 10 12 

speed'" (m s-l) 

Direction of max. 013 032 014 018 359 030 031 012 017 339 320 013 

... ·ind (deg.) 

Average station 682. 682. 7 681.1 682 3 679 8 676 2 679.0 663 3 672 2 676.1 681 .2 685 8 

pressure (mb) 

Maximum pressure· .... 691 694 692 700 697 690 691 680 685 699 690 703 

(mb) 

Minimum pressure'';- 674 670 671 670 665 662 661 649 656 659 673 673 

(mb) 

Average air -28 0 -39 2 -53 6 -50 6 -56 4 -60 2 -60.1 -62 .1 -59 9 -48 5 -36 2 -25.8 

tempe r a tu re (OC) 

~Iaximum temperature"'" -21 -29 -44 - 37 - 39 -39 -45 -41 - 38 - 30 -29 

(OC) 

Minimum temperature"" - 37 -56 -65 -64 - 71 - 75 -68 - )) -)) -66 -47 

(0C) 

,,"Naximum and minimum values are hourly averages. 

3.9 . 4 Samoa Climatology 

Since the relocation of the meteorological sensors atop Lauagae Ridge at 

Cape Matatula in February 1977, wind, temperature, and humi dity have been 

measured from this position. At t his l ocation t he anemometer is pl aced abo ut 

-13 

- 36 

85 m above sea level, and the temperature measurements are made at 75 m above 

sea level. The records indicate the persistant nature of the trade winds from a 

southeasterly direction (fig . 31). On more than half the hours in the year the 

wind is from this direction. Also t he stronger winds are from t he southeasterly 

direction. The average wind speed for the year 1978 was 4.7 m s -1 Calm winds, 

an average wind speed of less than 0.5 m s - l, were observed 1.6% of the hours. 

The constant nature of the climate at Cape Matatula is clearly illustrated 

in table 17. There is only a s mall indication of s tronger winds and cooler 

temperatures in winter than in summer . The average temperature for 1978 was 

27.6°C, with the maximum and minimum hourly values at 33°C and 22°C, respectively. 

Diurnal variations of wind and temperature are also small. Due to the diurnal 

pressure wave in the tropics the diurnal variation in station pressure is greater 

than the annllal variation (tliller, 19 75). The average station pressure for 1978 

was 1000 . 5 mb. 

58 
N 

CAPE MATATULA ~ 

AMERICAN SAMOA 1978 

~­

S 

Table 17 . -- 1978 Samoa Obse rva t ory 

J,n Feb Ia r Ap' tiay 

Prevai l ing wind NNW SE """ SE Sf. 

direction s 

Average \,'j nd 4.8 2.7 4.6 3.2 4.6 

speed (m , ' ) 

tiaximum wind 12 8 12 9 II 

speed";' (m s - I) 

Direction of max. 326 325 320 150 147 

""ind"c (deg. 

Average sta Lion 999 . 1 997. I 1000,3 100 1,2 1001.8 

pressure (mb) 

naximum pressure'" 1005 1005 1007 1006 1007 

(mb) 

Ninimum pressure': 990 989 996 996 996 

(mb) 

Average air 27 . 6 28.6 27 ,4 27.9 27 . 8 

temperature ( Oc) 

Naximum temperature';' 31 33 33 32 31 

(Oe) 

tlinimum lcmperaLure; ' 25 25 22 24 24 

(Oe) 

"'Maximum and minimum values a re hourly averages. 

59 

Figure 31.--As in f ig. 28, except 

for Samoa Ob s e r vato ry. 

mo nt hly cl imat e s ummary 

J un J u l Au, Sep 0" Nov Dec 

SE SSE SF SSE SE SSE SE 

6.5 5.6 4.8 4.4 5.0 4 . 7 5.2 

10 12 10 10 14 12 II 

122 144 138 11 6 143 124 324 

1001.8 100 1. 9 100 1,1 1001.7 1001.3 999.9 999.2 

1005 1007 1007 1006 1008 1005 1004 

998 999 988 998 996 996 993 

27.5 27. 1 27.0 27.0 27.6 27.3 28.2 

31 31 33 30 32 34 34 

23 24 22 23 24 23 23 
3 . 10 Precipitation Chemistry 

easure nts of precipitation chemis try were continued at the 4 base line 

observatories, 10 regional stations, and 6 Washington, D.C., area s ites . Monthly 

samples were returned from the baseline and regional sites to EPA and DOE laboratories for analysis . Throughout the year, event, biweekly, and weekl y samples 

from Hawaii, Samoa, and Alaska were analyzed at the tlLO Laboratory in Hilo for 

pH, condu ctivity, and selec ted a nions . A special project to s tudy the dire c t 

effects of the Kilauea Volcano on the local prec ipitation chemistry (s ee t able 18 

for outline) was conducted by D. Harding. Earlier issues of the GMCC Summary 

Report give details on collection sites, co llection te chniques , etc. 

3 .1 0. 1 Base line Meas ureme nts 

The pH measurements from the monthly collection program are s hown i n fig. 32 . 

Misco ind ica t es that sampl es were co llected in a tlisco collector and s hipped to 

EPA for analysis . The EML data are mon thly samp l es , col l ected in a n Aerochem 

I 

c. 

I 

c. 

8r------------r-----------~1------------~1---------------, 

Samoa 

7-

o o 

6-

o 

5-

4-

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o 

o o 

o 

o 

o 

-

-

& 

o g _ 

00 

-

3~----------------------------------------------------~ 

7-

61-

5-

4-

Mauna Loa 

o 

o 

o o o 

o 

o 

o o 

o 

o o 

o 

o 

o 

o o 

o 

o 

o 

(:; 

(:; 

-

-

~" 0 0 0 O .•....•• r.: . .It. iIt .! ..... ...... '. : .. ·,,· .. ·· .... ·0 

....... -

3~--------_~1--------~1----------~~----------~ 1973 1974 1975 1976 

Figure 32 . --pH values meas ured at StlO and MLO in monthly rain samples sent to EPA 

(Mis co - 0) a nd EtlL (6) for ana l ysis. Bulk ph values measured on site are plotted for tlLO (.). 

60 
I 

c. 

6r---------.---------------.--------------,----------------~ 

5 

4 

\ 

\ 

\ 

\ 

" I \ 

I 

I 

I 

I 

I 

I I 

I I 

I I 

I I 

V 

----Hila 

----- Kulani 

3L-________ L-______________ L-____________ ~L_ ______________ ~ 

1975 1976 1977 1978 

Figure 33.--Average monthly pH values at Hilo (120 m) and Kulani (2500 m) 

co llected in bulk collectors on a daily or biweekly collection schedule a nd 

analyzed on site. 

etrics collector, tha t are shipped to the Environmental ~1easurements Labora tory) 

DOE, for analysis. The Samoa samples are fairly consistent during tile 4-yr period. 

The ~launa Loa pH values, however) show large scatter because of such factors as 

wide variability of precipitation amount, sample evaporation, or failure of the 

collector to open. In contrast, the pH values of samples from a bulk or open 

collector (biweekly) show consistently lower values when averaged over the month . 

ILO staff, wi th EPA and DOE, are inves tigating this problem. 

Examples of monthly weighted averages from two other sites i n Hawaii are 

s hown in fig. 33. The Hilo site (120 m) and Kulani site (2500 m) represent a 

low-level marine and a high-altitude environment, respectively, well above the 

trade inversion. Values are generally well below pH 5.0. Figure 34 shows a 

s umma ry of all sites on Hawaii . The increase in acidity with elevation reported 

in ear lier Summary Reports can still be seen . 

Because of possible local contamination by volcanoes on the Island of Hawaii, 

a site was established on the Island of Kauai about 500 km north. The first 

4 months of data are almost identical to those from a s imilar site on the Island 

of Hawaii (fig. 35). The pH values represent monthly weighted averages of event 

samples measured on site at both locations. This similarity is one indication 

that samples collected on Hawaii are representative of regi onal precipitation. 

61 
Tabl e 18.--Prec ipitation chemi stry programs in GMCC 1978 

Type of 

program Loea tion No . sites Sponsor 

Baseline ~Iauna Loa S DOE, EPA 

Samoa 2 DOE , EPA 

Ba rrow 1 URI 

Sou th Pole grab sampl es 

Regional 10 EPA 

Local Was hington , D.C. , 6 

a rea 

Special research Kilauea Volcano 

(Harding) 

--MLO 

--- Kulanl 

40 

r. -.- Hilo 

• \ -. - Kumukahi 

I ° 

i \ 5.0 

° 0 j \ 

30 

• • • 

u • 

a 

.; 

z 

/ ° 

° \ / ° 

° \ I ° 

-----..... ............... 

20 i \ -\ ~ 4 .5 

• V. • 

10 

/ ,-- / i \ I /~_/ l __ /. \. \ 

all ;.,_, 0\ 

_. \ ° \ \ 

/) .. -. --. \ 

~ 0 \ 

111381 HI H11 411Ul 431 H I HI 4 51 01 4 8"" ~Ol ~u 521 531541 38-39- 4 0 -4 1-42_4 3 ., - 45-46 ' /48-' 9-50 -51 -52-53 54-55 

pH Interval 

Figure 34 .--Histogram of all pH values 

meas ured on t he Island of Hawaii 

during a 3-yr period at the ma in 

four collection sites . 

62 

• Kauai (150m) 

o Halai (120 m) 

4 .0 L.-L.. __ ....L __ --L __ --L __ --L----l 

A SON 

1978 

D 

Figu re 3S . --Average monthly pH val ues 

meas ure d on the Island s of Kauai 

and Hawaii. 
3.10.2. Regiona l Site Evaluation 

Reevaluation of the regional sites began in 1978 with visits to Pendleton, 

Ore., Bishop, Calif., and Alamosa, Co l o . New Aerochem Metrics collectors have 

been received and will be shipped to the sit es in 1979 . Figure 36 shows a summary 

of the pH data from five eastern stations . Although pH values were low (4.0) 

during the 5- yr period, no discernible tre nd can be detected. 

3 . 10.3 Local Washington , D. C. , Networ k 

I n contrast to the regi onal sites, with monthly co llections, the sixs t ation network i n the Washington, D.C ., area shows a definite seasonal cycle 

but no yearly t rend. Samples are collected on a n event basis. Figure 37 shows 

the areal weighted pH values plotted f or the 4-yr period . A peak in acidity 

(low pH values) can be seen during each s umme r season . 

3.11 Rain Chemistry at Kil auea Summit 

Hawaiian rainwater has been collected and analyzed for pH by Mauna Loa 

Observa to ry for 6 yea rs. However , sinc e the summit of Kilauea Volcano has not 

been studied, a 1-yr res earch p ro j ect wa s start ed in Mar ch 1978. 

Six rain collection sites were established from 3.5 km northeast to 12 km 

southwest of the Kilauea Caldera (see fig . 38) . Each site had a plastic funneland-bottle co llector for 3- t o 4-day integrated samples . In addition, there 

were six 32 - qt bu ckets ; each could be lined with a polyethylene bag for event 

samples . Rainfall was measured with a 4-in plastic rain gauge . 

Sampl es were co llec t ed twice a week from May 1978 through February 1979. 

All sampl es ~'ere a nalyzed i n 3 days o r l ess for pH a nd conductivity. The samples 

were later ana lyzed with the ion chromatograph for the anions F-, C1- , N0 2-, - 3 - -2 P04 , Br , N0 3 , and S04 . 

_ The major anions in the rainwater were fo und to be Fl-, C1-, and especially 

S04-' The pH of a rain sample depends on the following factors: location of the 

pollutant sources and their source strengths, location of the sample collector, 

wind direction, wind speed, and rainfa ll intensity. 

Kilauea Caldera, particularly Halemaumau pit, is the major source of rainwater contaminants i n the sunun it area. R. Sto iber and L. Nalinconico of Dartmouth 

College were invited by Mauna Loa Observatory and Hawaiian Volcano Observatory 

to measure the output of S02 gas from Kilauea Caldera. By using a correlation 

spectrometer, they measured an emission rate of 200 Mg day-1. In contrast, they 

found that the S02 flux from ~!auna Loa Volcano was below the de~ection limit of 

the spectrometer; the output was estimated a t 0 . 5 to 5.0 Mg day 1. The spectrometer was also used to measure the S02 outgassing at the Sulfur Banks area of the 

national park. The test showed littl e, if any , S02 outgassing at the time. 

More measureme nts wi ll be needed to determine how the emission rates of gasses 

and particles vary with time at the sites tested. 

Six recording wind va nes were se t up to t est whether the Kilauea summit 

area is dominated by trade wi nd s. Although four va nes were original l y connected 

to Esterline-Angus chart recorders, the recorders started to corrode within 

63 
r-r------,------,------,------,-------., 

Caribou,Me 

I 7- '" ;- 5 .. ..... . 

.. 

•• 0' 

• 0 0 ' • • ••••• 0 0 ' •••• • 0° •••• ,0, •••• 

I 

0. 

I 

0. 

I 

0. 

3~--------------------------_4 

Atlantic City. N J 

.. 5 • '. eo '.:'.' ••••• .0' •• •• ,° •• 0° ••• :·.0. " 0°' 

3F---------------------------~--4 

Ralelg h,N.C. 

5 ••• ••..••.. ••.• • '. .0. '0. '0....", 0, • " •• ' , •• , 0 •• •• • ... 

3F-------------------------------4 

Salem,lIl 

5 r- ., . • • • •• • '0. 0 •••••••••••••• ,0 ,'0· .° 0•• • '0. '0 ••••••• 

3~~~~~~~~~-l~~~~~-l~ 

1972 1973 1974 1975 1976 

4.9 

4 .8 

4.7 

4.6 

4.5 

4.4 

4 .3 

'E. 4.2 

4.1 

4 .0 

3.9 

3.8 

3.7 

3.6 

H 

1975 

Annual 

Weighted 

Va lue 

pH 0 409 

H 

1976 

Annual 

Weighted 

Value 

pH 0 405 

Figure 36 .--pH values meas ured at 

four IVI'lO regiona l sites . 

H 

1977 

Annual 

Weighted 

Value 

pH 0 4 .09 

Annual 

Weighted 

Value 

pH o 4 .14 

1978 

I-----l 

3 .5 J F M AM J J AS 0 N D 

1975 

JFMAMJJASONDJFMAMJJASONDJFMAMJJASOND 

1976 1977 1978 

Figure 37 .--Average areal we ighte d pH va lues for Washington, D.C., area. 

64 
weeks and were removed. Only a portable weather station at the far southwest 

end of the network recorded continuously throughout the year . Charts from the 

one recorder plus visual observation showed that trade winds commonly occur only 

in the i mmediate vicini ty of the summit and north and south of it. Several 

kilometers southwest of the sun~it the winds are often anabatic (local upslope) 

from the southwest. This discovery was tempered by the discovery that the 

convergence area is known as Namakani Paio--dueling winds. 

Nearly all daytime rain periods can be described by the diagrams in fig. 39. 

In type 1, the trade winds are strong . Southwest of the caldera the clouds 

quickly evaporate in the downdraft. Often heavy rain changes abruptly to blue 

s ky . In type 2 rain period, the trade winds are lighter. On the sunny southwe s t 

side, the upslope winds lift the trades, which carry scattered showers towa rd 

t he southwest. Type 1 weather appears to prevail whenever the wi nd sp eed northeast of the caldera i s greater than about 15 mph. Type 3 represe nts the rain 

caused by t he anabatic winds. On most mornings upslope winds c reate one or two 

-- \ N 

~ 

0 2 

km 

• Collector Sites 

• Park Headquarters 

3000ft~ • Volcano Obs . 

Figure 38.--Rain collection sites near summit of Kilauea Volcano. 

65 
bands of stratocumulus on the southern flank of tlauna Loa and above the valley 

northeast o f Kilauea. Sometimes, strong convective activity develops and mass ive 

cumulus congestus form in about an hour. Once the cloud top reaches a critical 

height, the cloud mass quickly spreads laterally and encroaches on the edge of 

the collection networ k at Firing Range. This type ha s been observed mo stly in 

the s unmle r . 

Because of the reliability of the winds , the measured pH values at any 

station (fig. 40) were grouped into general regimes: pH 4.0 to pH 5.2 at Golf 

Course; pH 3.2 to pH 4 . 0 at SW Rift; and pH 3.8 to pH 4.6 at Firing Range. The 

lowest measured value was pH 2.99 at SW Rift. 

For fig . 40, the 4-wk running average was computed to smooth out the data. 

For most of the year, the pH was l owest a t SW Rift and hi ghest at Go lf Course. 

However, during winter months southwest winds are more common, and the average 

pH increased at both SW Rift and Firing Range and decreased at Golf Course. 

Kilometers 

66 

Figure 39.--Four types of rain occurrences at Kilauea Caldera. 
6~-r-----r-----r-----.-----.-----.-----.-----.----~------r-----' 

I 

0. 5 

'" '" GC ~ 

'" > 

<t 

'" 

" 

~ 

'" '" 

4 ~ SW 

3L--L ____ ~ ____ ~ ____ L_ ____ L_ __ ~ ____ ~ ____ _L ____ _t----~----~ 

Feb 

1979 

Figure 40.--Four-week ru nn ing averages of pH for three sites: Golf Course (GC), 

Firing Range (FR) , and SW Rift (SW). 

3.12 Data Management 

3 . 12.1 Data Acquisition 

Hardware 

In 1978 the reliability of the Instrumentation Control and Data Acquisition 

Systems (ICDAS) at the observatories improved greatly. For all stations combined 

the system was off line an average of 23 days in 1977, an improvement of 52 days 

over 1977. The ICDAS at MLO was down during much of 19 78 causing the relatively 

large value in fig. 41. The renovation of MLO and the installation of central 

air-conditioning created a better operating environment for electronic components . The performance at the other stations improved in part because of startup 

software changes; specifically, the restart procedure was made easier for the 

operators and more reliable because it ensured the correct positioning of the 

tape. The new program also recaptures calibration constants automatically from 

the last hourly record on the data tape. The most reliable system was at the 

South Pole where the total down time was only 8.6 days. 

The noise in the field data acquisition systems at both audio and radio 

frequencies was dealt with this year. The primary source of the noise was the 

power supply of the mini computer. Linear power supp lies of s uffi cientl y small 

size were fou nd to replace the noisy switching s upplie s furnished by the manufacturer . After extensive testing, the linear power supplies were installed in the 

67 
a: 

'" w 

>-

~ 

o 

w 

~ IZ 

w 

U 

a: 

w 

~ 

'.6 

SOUTH 

POLE 

SAMOA MAUNA 

LOA 

BARROW 

Figure 41.--ICDAS operations for 

1977 /1978. 

minicomputer in the training facility and in the reduction facility. Noise 

leve ls were reduced by as much as a factor of 5 at the input to the system . 

Linear power supplies are to be installed in the minicomputers at the stations 

in 1979. With the elimination of the noise from the switching power supply, the 

staff can begin a systematic evaluation of other noise sources. 

Another major hardware project involved the adaptation of the ICDAS to 

accomodate ddLct iIi digiLal form . The standari zed CAl"lAC system had been purchased 

earlier and evaluated for this purpose . Unfortunately, the interface electronics 

were unreliable and the cost and software overhead excessive . A simpler solution 

that used a DGC NOVA communication port with an RS-232 compatible port and 

standard communication protocol will be explored. The prototype of the CO 2 

reference tank controller (see fig. 42) was designed and built. Final testing 

\vas completed early in 1979. A microprocessor was used to control the order i n 

which CO 2 reference tanks were sampled and to digitize the resulting signals . 

Figure 42.--Prototype CO 2 reference tank controller. 

68 
Table 19.--Inventory of GtlCC data tapes sent to WDC-A 

No. Tape Date of Parameter Stations Period 

name issue of data 

GPOPOI 1/16/78 Aerosol count BRW 1975, 1976 

tlLO 1975, 1976 

SPO 1975, 1976 

2 A78076 3/17/78 Solar irradiance tlLO 1977 

3 A78083 3/24/78 So l ar irradiance StlO 1977 

4 A78100 4/10/78 Solar irradiance BRW 1977 

5 A78104 4/14/78 Solar irradiance tlLO 1976 

6 A78132 5/ 12/78 NIP radiation BRW, tlLO 1977 

StIO, APO 

7 A78139 5/19/78 Wind, pressure, BRW, tlLO 1977 

t emp. , humidity StlO , SPO 

8 A78146 5/26/78 Solar irr-adiance StlO 1976 

9 A78160 6/9/78 Solar irradiance SPO 1976, 1977 

10 A78230 8/18/78 So la r irradiance BRW 1976 

I I A78272 9/29/78 Solar irradiance BRW, tlLO First half 

1978 

12 A78279 10/6/78 Solar irradiance StlO First half 

1978 

Software 

tlinor problems with the operating software were identified and corrected. 

An IILO probl em with t he control of the CO 2 reference gases after a power outage 

and a tape positioning problem were corrected, and the start-up procedure was 

further streamlined. The time between changes of the data tape was increased 

from 10 t o 14 days . The revised operating software was issued as Basic Op e rating 

Software System (BOSS) 79001, replacing BOSS 77280 at all stations except the 

South Pole, which will be upgraded next year. 

3 .1 2.2 Processing 

Reduction of Station Tape s 

During 1978 two ma jor hardware problems in the reduction laboratory slowed 

processing of ICDAS data tapes. During the first half of the year , the phaseencoded monthly tapes produced in the reduction lab could not be read on the 

69 
tape drives in the NBS computer facility. After much testing we determined that 

the read-write head of the drive in the reduction lab was recording at very low 

levels. Replacing it with a new head from the factory solved the problem. 

Second, the heads crashed on the disc drives, which are used for program storage 

in the reduction lab. While the drives were being repaired, many programs which 

process the field data tapes could not be rlln; most of these programs have been 

put on backup image tapes so that they can be run without the disc drives. 

Beginning ~ith January 1978, we decided to rerecord each monthly tape on 

the CDC 6600 in internal format. This procedure ha s two purposes: to provide a 

tape created in the most reliable format for use on the CDC 6600, and to produce 

a tape in CDC 6600 floating point format so that the conversion from NOVA BASIC 

is made once and not every time the tape is accessed on the CDC 6600. 

Ne\y Software 

Design and programming of the CO 2 continuous data base were completed in 

mid-year. The software reformats ICDAS and old card data and allows missing 

data to be inserted from strip charts . The data may be edited and output as 

daily tables of hourly values . Likewise, software to process meteorology data 

was developed throughout 1978. These programs edit the data statistically and 

climatologically and allow missing data to be inserted from strip charts via 

cards before final checking, a climatology run, and archiving. 

3.12.3 Archiving 

Table 19 lists the names of magnetic tapes sent to the National Archive in 

1978. Data on the tapes are blocked into files, each file being preceded by a 

section containing a description of the data in alphanumeric form. Copies of 

the GNCC tapes ca n be obtained from the Computer Production Branch, National 

Climatic Center, Asheville, NC 2880 1, FTS 672-0203 or (704) 258-2850, ex . 203. 

70 
4. SPECIAL PROJECTS 

4.1 The Short Umkehr tlethod 

A theoreti cal study was performed to explore the possibility of shortening 

the 2-3 hours required for a Dobson Umkehr observation by incorporating more 

\vavelength pairs in the mea s ureme nt procedure . In essence, the Umkehr measurement uses wavelength in place of so lar zenith angl e as the independent variable . 

Practical and physical limita tions restrict t he variable wavelength method to 

solar zenith angles 75° <80 <90 0 , We used solution residual variance and correlation criteri a to judge the statistical informa ti on o f each method to establish 

a degree of equivalence between the two. To check the validity of the theoretical approach, a limite d eigenvalue analysis was per formed on the synthesized 

Umkehr observations, and this wa s compared with eigenanalyses on real Umkehr 

data reported by other investigators. 

4 . 1.1 Residual Variance 

This section is a n extension of the preliminary work reported in GHCC Summary Report 19 77, section 4 . 1. Of partic ular interest is the behavior of the 

diagonal e lements of cova ria nce, S;_f and Sf (1 is a solution vector and 1 is 

an observation of ozone profile), th; difference of wh i ch may be interpreted as 

information added by the radiation mea s urements . We used a variation of the 

Ivestwater-Strand (19 68) method of evaluation. Figure 43 shows ai_f' which is 

the s quare root of the diago nal elements (root-mean-sguare deviati';;'n or RNSD) of 

S~_f' and for measu rement errors of 1% a.od 10%. From fig. 43 we see that a;_f' 

i;;r ...... a 1% measurement error, i:-:; aL lea st one half or smaller than the magnit~de of 

of for the observed ozone profile s . For a 10% mea s urement error the R~ISD becomes 

l;rger, but significant information is still gai ned in certain levels, e.g., layer 

6-8. The solid line for a f is the limit beyond which no new information would 

be availab l e . Little diff;re nc e is seen between the results of the mw (short 

method) and Umke hr method, which indicates that they do not differ greatly . 

4.1.2 Correlation Be twe en 1 and f 

Next we examine the correlation between! and ! , which can be interpreled 

as the degree to which the so lution ozone profiles fol l ow the actual ozone 

profiles . This correlation provides a measure of the nonrandom statistical 

information reproduc ed in S;. Figure 44 shows C; f which was derived under the ~ ~,~ 

same conditions , i. e . , using the maximum likelihood method and for measurement 

errors of 1% and 10%. The Umkehr and mw methods have almost the same correlations at every level, except for layer 1 fo r the 1% error case where a substantially lower co rrelation is seen for the Umkehr. The peculiar dip seen in the 

correlation for la ye r 5 is a region of transition, whe re the seasonal cycles of 

ozone above and below are out of phase by 4-6 mo. Note that the residual variance 

does not reveal a corresponding var iation in the transition region, although a 

variance anomaly is seen in the a priori statistics Of2 . 

4.1 . 3 Eigenanalysis of the Umkehr and mw ~lethods 

The first four normalize d eigenvalues and eigenvectors (lower table) of 

S (/l. is a measurement vector) for the Umkehr and mw methods in the present 

.e 

71 
Ii; 

D 

E 

~ 

z 

" '" ,.. 

m 

-' 

(1 °0 ) (10% ) Measurement Error 

9 " 

8 

7 

6 

1---- Ozonesonde Data Covariance 

5 

4 

3 

2 

o 0.1 0.2 0.3 0.4 0.5 A 

RMSD (f -f) 

0. 6 0.7 

mH 

Umkehr 

0.8 0.9 

Figure 43.--Residual root mean square deviations connec ted by stra ight lines, 

showing r es ults of Umkehr and multiple-wave length (mw) solutions. Ozonesonde data plot is l imit at which no new information is available from 

measurements . t is solution ozone; f is hypothetical true ozone. 

Measurement Error (t00,0 ) (1%) 

9 !/ 

B ----Umkeh r 

7 

6 

5 

4 -- 3 

2 

-----' 

-- --- ------ --

----

0L------0~~1----~0~2----~0~.3~ 04 05 06 07 08 0.9 A 

Correia! Ion Iff) 

Figure 44.--Correlations between t (solution ozone) and f (hypothetical true 

ozone) connected by straight lines. 

72 

1.0 

1 0 
Table 20.--Comparison of first four eigenvalues E. of S 1 t 

Umkehr (present study) 

mw method (present study) 

Umkehr Ula tee r, 1965) 

Umkehr (Craig, 1976) 

0.741 

0.826 

0.656 

0.709 

0.239 

0.167 

0.293 

0.238 

0.019 

0.005 

0.030 

0.034 

0.001 

0.001 

0.009 

0.006 

study are given in table 20. Also included are eigenvalues from the results of 

Mateer (1965) and Craig (1976). Inspection of the Umkehr eigenvalues from all 3 

sources does not reveal unusual differences. Some difference should be expected 

i n t he results of this study because it deals with synthesized Umkehr data whereas the analyses by Matee. (1965) and Craig (1976) were done with real data. Other 

factors that may contribute to the differences are the omissi on of total ozone 

used in t he other analyses, unaccounted nonlinearities in the method used to 

calcula t e S , different kinds of errors in S between actual and synthesized g g 

data and differences in locations for Umkehr and ozone sonde data. Mateer's (1965) 

data were for North America and Craig's (1976) data were for Tallahassee, Fla. 

4.2 Evaluation of the Robinson-Berger Meter Response 

The Robinson-Berger (RB) meter measure s UV flux in a moderately wide 

wave l e ngth band that simulates the human skin action spectrum. However, the 

band pass o f t he RB meter is not exactly like that of the human skin action 

spectrum, and it thus allows more UV radiation to bias the instrument's readings. 

The extent to which this bias ma y be serious is not well known. In the present 

i nvestigation \"e will evaluate the performanc e of the RB meter by making simultaneous, c l ear-sky solar radiation measurements with an RB meter and with a 

higher quality spectroradiometer, calibrated in absolute radiometric units. The 

spec t roradiometer measurements are convoluted with the human skin action spectrum. 

The units of the RB-meter measurements are minimum erythemal doses (HED's), 

\"he re one ~1E D is t he amount of UV radiation just sufficient to produce a reddeni ng of un tanned human skin . The method used to calibrate the RB meter is no t a 

part of t he present evaluation. The spectroradiometer measurements are given in 

terms of absolute units IJW cm- 2 , and since a conversion factor does not exist 

for t he RB meter, the two measurements ca nnot be related directly. Thus we 

c hose t o compare the two measurements on a relative basis with respect to a 

c hange in sola r zenith angle. During the course of a change in solar zenith 

ang l e , say over t he period of a few hours, if the two instruments disagree, a 

di vergence or convergence in the mea surements will occur. 

Figure 45 shows the results of some preliminary analyses for solar zenith 

angles 5 1°, 59°, and 67°. Straight lines join the points for the various measurements s hown on the graph . The curve labeled NED represents the RB measurements 

and has a scale on the eight-hand side. The calculated RB curve is found by the 

convo l ution of a published RB spectral band pass "ith the spectroradiometer 

meas urements. The calculated erythermal curve i s found by convoluting the human 

s kin action spectrum with the spectroradiometric measurements. The curve labeled 

Dave (307.5) is taken from published theoretical calculations of monochromatic 

73 
103 ,--r--------------~------------~__, 103 9 

6 

7 

6 

5 

E 4 <.> 

~ .3 3 

x 

~ 

u: 

en , a: 

102 1 

9 

/ MED (Righthand Scale) 

c~ 6L--L ____________ _L ________ ~ __ _L~ 

10' , 

9 

6 

7 

0;- 6 

E 5 <.> 

~ 4 .3 

x 

~ 3 u: 

"iii 

E 

ru 2 .c 

~ w 

100 1 50' 

Calculated 

Erythemal 

Dave (307.5)-----

60' 

Solar Zenith Angle 

" ru 

~ 

o 

o 

"iii 

E 

ru 

.c 

~ w 

E 

~ 

E 

c 

:;; 

en 

a: 

10' 

Figure 45.--Plots of UV r adiation 

vs. solar zenith angle. 

hemispheric radiation at a wave l e ngth of 307 . 5 ~m and tota l columnar ozone of 

.341 cm STP (Dave and Furukawa, 1966). This wavelength happen s to be quite 

close to, if not directly at, the peak of the convoluted human skin action 

spectrum and the incident hemispheric UV flux. 

In fi g. 45, the slope of the calculated erythermal response is steeper than 

the RB-meter response, implying that they diverge with increasing solar zenith 

angle. This is consistent with the RB-meter spect ral band pass, which permits 

UV radiation at longer wavelengths to pass o nward to the sensor. The calculated 

RB response i s seen to be quite bad. We found later that more RB spectral 

response curves were published and the one used was the wors t available. 

The Dave curve in fig. 45 falls off more steeply than all other curves. 

This occurs because the ozone, .34 cm STP, for Dave's calculations is considerably higher than the .27 cm STP. Ca lculatio ns with correct ozone amounts will 

be used in the future comparisons. 

In summary, the RB-meter measurements depart significantly from the spectroradiometric measurements. A more in-depth analysis will be performed on the 

remaining data to quantify the magnitude of the departure. 

74 
4.3 Umkehr Vertical Ozone Profile Errors Ca used by the Presence of 

Stratospheric Aerosols 

The present investigation is conce rned with errors to the Umkehr ozone 

profiles following the violent eruption of flount Agung in 1963. Large quantities 

of aerosols from the eruption were injected into the troposphere and s tra tosphere 

over the Southern Hemisphere. A s ho rt time later, increases in stratospheric 

aerosol concentrations were observed in the Northern Hemisphere. Following 

Agung a dramatic change occurred in Umkehr ozone profiles observed at Aspendale, 

Australia. Sma ller , bu t nevertheless s i gnificant, changes to Umkehr oz one 

profiles also occurred in the Northern Hemisphere record, which consisted of 

data from several sta tions. 

The changes to the ozone profiles at Aspendale are so l arge that it is 

possible to deduce empiri call y the haze error effects t o the Umkehr oz one 

profile by comparing averages of ozone profil es observed almost i~nediately 

afte r Agung with ozone profiles observed for several years when the stratosphere 

was without serious aeroso l con taminati on. 

The present investigation also involves a theoretical approach in which 

aerosol errors to the Umkehr meas urement are calculated and, accordingl y, corrections are made to deduced ozone profiles. Hodel vertical profiles of aerosols 

and observed changes to stratospheric aerosol optica l depths are used for the 

calcul ations. Insight into the physical processes that are responsible for the 

caus e s of the ozone profile errors is gained from t he theoretical approach. 

Figure 46 s hows two plots of haze errors to the Umkehr ozone profiles as 

determined from the Aspe nd a l e data. Two-month averages are used, J tlne -Jlll y and 

"" 0 

0: 

0 

g 

0 

-

§ 

w 

~ 

0"r--'---'---'--'---'---~--'--'" 

60 

50 

40 

30 

20 

10 

0 

- 10 

- 20 

-30 

- 40 

48 

- 50 

............. 

\ '\ 1_,_ June·July 

EmpIrical 1----- Aug .-Nov. 

\ \ Theoretica l Models I-rn 

\, \ 

~ \ 

~ \ \D Aspendale Dat a 

~r 

\ \ 

" \ 

:'\ \ \ . \',\ . ~ 

.... '-.'~~~~~:;~<\. ........ . ·-'.V" " .. 11 

29 ,;, 18 

2 3 

10 

4 

\. '-, m' 

\ " "~, 

~, '~\ 

a p "\.\ 

--p- "\ 

5% 6 :{. 11 1.. 11% 16% 

5 6 7 8 9 

l a yel Number 

Figure 46.--Umkehr ozone profile haze 

errors. Plots for Aspendale data 

were empiri cally determined ; pl ots 

I, II, and III were theoretically 

ca l cula t e d by using mod e l vertical 

aerosol concentration profiles. 

75 
12 

E 8 

o ~ 

-= c c 0 

N 4 00 

~ ~ 0 > ~ 

~::; 

0 , - , c ~ -4 ~ ~ 

u ro ,-, 

~ -8 "-

-12 

Corrected Umkehr '-......... 

Ozone 

1960 

Year 

Figure 47_--(top) Stratospheric aerosol corrections to annual means of 

the lower plot_ (bottom) Observed 

deviations of Umkehr ozone concentrations from the long-term mean 

in a layer from 32 to 46 km. 

August-November, to increa se the number of data points for a smoother plot . 

Also plotted on the figure are theoretically calculated haze errors. Below the 

plots the observed standard deviation divided by the average partial pressure 

for the sumnler season at Aspendale is given for each layer. These values, 

derived from a set of about 100 observations during about 10 years, show the 

normally expected spread in observed ozone profiles plus errors intrinsic to the 

Umkehr method. 

4.3 .1 Haze Error Correction 

The correction procedure is specifically intended for an increase in 

stratospheric aerosol content in the Northern Hemisphere following the eruption 

of Agung. Atmospheric t ra nsmission data from Mendonca et al. (1978) indicate 

than an average increase of stratospheric aerosol optical depth of 0.014 occurred 

in the Northern Hemisphere temperate latitudes during 1965. In the years subsequent to Agung the transmission varied considerably as it slowly tended toward 

the pre-Agung values. 

Figure 47 shows a smooth plot of Umkehr ozone data (lower plot) representing 

the sum of the absolute abundances of ozone in layers 7-9 (or a layer approximately 32-46 km thick) versus time (Angell and Korshover, 1978) for 10 stations 

in the north temperate latitudes. The ordinate is the percent deviation in 

ozone from the long-term mean . Tick marks on the abscissa represent the middle 

of the year . Also s hown in the figure is a hatched area plot of corrected 

midyear Umkehr ozone concentrations (upper plot) for the same 32- to 46-km 

layer. This area plot depicts the range within which the actual ozone abundances 

are more likely to exist. Corrections to the lower plot are based on the estimated 

upper and lower limits of the change in the observed optical depth for each year 

from 1963 to 1976. 

4.4 Confidence Interval for CO 2 Flask Sampling 

A primary task of the GMCC measurement program is to determine the true 

mean va lue of a particular pollutant in the atmosphere. A model suggested by 

Hunt (1972) defines the precision with which discrete samples of an atmospheric 

constituent or pollutant represent the true mean value, when the constituent is 

assumed to be log-normally distributed. In this study, the 1977 CO 2 data (both 

continuous and flask sampling) from the South Pole and Samoa stations will be 

used to determine the confidence limits that must be assigned to flask sample 

76 
concentrations based on the geometric standard deviation and the sampling and 

averaging peri od . 

4.4.1 Nature of Variability 

The statistics used to test Hunt' s model were drawn from continuous 1977 

(hourly-averaged) measurements of the concentration of atmospheric carbon dioxide at the Amundsen-Scott station at the South Pole, Antarctica, and the GflCC 

station at Cape Matatula, Samoa. For both s tations long-term trends and the 

annual cycle were removed by evaluating the distribution and statistics from the 

residual val ues form ed by subtracting the monthly mean values from the data. 

The resulting distribution (fig . 48) shows good agreement with a l og- normal 

distribution over the upper 90% of the data . The geometric standard deviation 

of 0.2 ppm was computed from the South Pole data; the Samoa data gave a larger 

value of 0.7 ppm. 

4.4.2 Results 

In fig. 49, the results of model calculations with sta ndard deviations of 

0.2 and 0 . 7 are plotted. Confidence intervals of 80% and 90% are graphed, 

assuming a mean va lue of 330 ppm; the uncertainty in the month ly me an values 

ranges from 0 . 1 to 3.0 ppm. Flask sample data currently used by GfiCC are collected on 2, 4, and 8 days mo-'. These data were compared to the 30 daily 

values per month obtained from continuous sampling. The expected difference 

between the sample geometr i c monthly mean CO2 concentration and the true geometri c monthly mean concentration was therefore determined at two confidence 

l eve ls and two levels of variability, and over a wide range of sampl ing intervals. For wPpkly sampling the unc ertainty at t he 90% level for tropical mea surement is on the order of ± 0.7 ppm and for Antarctica about ± 0.2 ppm. Doubling 

the sampling rate reduces the un certainty by a factor of 2. If the basic uncertaint y of the measurement is on the order of ± 0 . 2 to ± Q.3 ppm, little will 

be learned by sampling more frequently than 4 to 8 times rna' A standard 

C 

c 

1 ')'0 

100':-

1 ooo~ 

99'~ S 

K =10 

• --j 

• 

• 1 995-

• 

• 

993~ • 

, 

991 1 

• 

I I I I 

" 10 30 50 70 90 99 999 

Probab,I'l,' 

Figure 48.--Cumulative probabillty of equaling a particular 

CO 2 concentration ratio (C/e) . Data from South Pole. 

77 
30 

6.C 

3 

2 

\ 

\ 

6 

\ 

, 

, 

2 

\ 

\ 

\ 

\ 

\ 

\ 

4 8 

I:. S 07 

o S ~ 0.2 

15 30 

Sarnpllng Rate (Days Per Mon th) 

Figure 49 . --Comparison of confidence 

intervals for sampling plans by using 

geometric standard deviations of 0.2 

(SPO) and 0 . 7 (SMO). 

deviation of 0 . 2 ppm is probably a minimum value applicable only at the South 

Pole. Further study of the detrended variability at all stations making continuous measurements is needed. 

4.5 Isotopes of Carbon: Effect of Adding Limestone Derived CO 2 to the 

Atmosphere 

Records of carbon isotopes provide considerable information on the carbon 

cycle . Ratios of carbon isotopes vary because of temperature , biological growth 

cycles, and changes in carbon pool content. Carbon 13 to carbon 12 ratios are 

valuab l e in determining the history of fossil fuel combustion since fossil fuel 

contains practically no C14 and a C13/C12 value lower than that found in atmospheric CO2 , This investigation attempted to foresee the consequence of converting carbonate and dolomite to atmospheric CO2 on C13/C12 observations. This 

fossil material also contains practically no C14 but is enriched in C13 compared 

with atmospheric CO2 , 

Table 21 summarizes t he sources of CO 2 derived from lime stone . Industrial 

emissions have been previously considered, but the contributions from gas wells 

(due to metamorphism of carbona te s) ha ve not been widely discussed . The figure 

8. 3 x 10 15g of CO2 is estimated from Rocky Mountain reserves in the United States 

Volcanic emissions of CO2 were obtained by assuming a ratio of unity for CO 2 to 

Table 21.--Estimated CO 2 atmospheric contributions from limestone 

Igneous intrusion into carbonates 

Gas wells Volcanic emissions 

0.0004 x 10 15g yr- 1 

0.000008 x 10 15g yr- 1 

Industrial emissions 

Portland cement Steel 

78 
su lfur gases and using the sulfuri c gas emission data of other sc i e ntists in 

the field. 

\yhen limestone-derived CO 2 is inj ected into the ai r , values of 6 13C are 

raised and rati os of C14 to tota l ca rbon are lowered. A simple model incorporating t he atmosphere (uniforml y mixed), the mixed layer of the ocean, and differing sources of CO 2 was used to calculate va lue s of 6 13C for differ ing source 

s t rengths . The model ass umed equilibrium for atmospheric-oceanic mixed-layer 

i sotopic ratio s and assumed the following for limestone: 

A quanti ty of 8 . 3 x 10 15g of CO 2 was inj ec ted into the atmosphere , and C13 

and C14 ratios were computed fr om the relationship 

U' atmos 

C atmos 

= 

F/G 

(1+F/G) 

C,', 

o,atmos 

C o,atmos 

(1 +G) + 

(1 + 2: 

i 

C,', 

i nj ected 

(OPC02 )i) 

PC02 

where C* i s the concentrati on of the carbon i s otope, C is the total 

a t mo s f CO C· . h . . . I h' a tmos . f th concentra t 1on 0 2, ~r 1S t e 1n1t1a atmosp er1C concentrat1on 0 e 

ca rbon i sotope, C °i~t~g~ initi al CO 2 concentration in the atmosphere. o,atnlOs 

1 + 2: (OPC02 )· 1 

i PC0 2 

F = (MC0 2 )· 1 + BL: 1 

i PC02 

where PC02 i s the partial press ure of CO 2 i n the atmosphere, (oPC02 ). is t he 

change of the partial press ure of CO 2 due t o addition of co ntribu tio~ i, and B 

is t he buffer facto r (assumed equ a l to 0.1), G is the initi al ratio of CO 2 in 

t he mixed l ayer t o that in the atmosp here, and U'.. d is the total quantity 

of carbon iso t ope inj ected into the a tmo sphere fr 6M ~1£esources. 

Injection of 8.3 x 10 15g of limestone-derived CO 2 into the atmosphere 

increases the 013C value for atmosp heric CO 2 by 0.042. The effect of raising 

the Ol3C value was moderated (reduced) by the ocea n. Although the effect of 

metamorphic CO 2 is no t large, it is sufficient to s how that all CO 2 sources 

s hould be i nventoried if de t a iled work on carbon i sotopes is planned. The 

importance of this source of CO 2 may be s hown from the ratio of increase of 6 13C 

va lues corresponding to a decrease of C14 ratios 

lI0 13C = -0.0848 

where 8 is t he decrease of Cl4 in percentage whereas for fossil fuel burning the 

relation 

was given by 8 tuiver (1978). Thus, a mixture of the t wo sources acting in two 

directions to change 6 13C could l ea d to faulty interpretations if one source 

were neglec ted. 

79 
4.6 Special Nephelometer Calibration Studies 

A 4-wavelength nephelometer was first installed at HLO in January 1974. 

Since then similar instruments have been installed at Barrow, Samoa, and So uth 

Pole so that a continuous record of data is being obtained at all GHCC sites. 

Calibration, the most important factor in any long-term meas ureme nt program, 

requires that field measurements be related to a fundamental, reproducible 

standard. In the past, nep helometers were calibrated by filling them with 

Freon-12 and adj usting the o utput voltage to agree with the known scatt eri ng 

coefficient of Freon-12. However, concern over the release of chlorofluorocarbons into the atmosphere and the fact that trace concentrations of FIl and F12 

are measur ed at the GMCC observatories preclude the use of F12 at these sit es. 

Consequently, carbon dioxide ha s been adopted as the calibration standard 

because its properties are well-known. 

To establish calibration standards for the GHCC program, experiments were 

undertaken at the Boulder laboratories (Bodhaine, 1979) to test the scattering 

properties of argon, air, carbon dioxide, and Freon-12. The scattering coefficients of these gases, which ha ve been accepted for the calibration of nephelometers in the GHCC program, are presented in table 22. 

These scattering coefficients are given for standard temperature and 

pressure (STP). Therefore, they must be sca led by density to t he operati ng 

temperature and pressure at each meas urement site. 

\;avelength 

(nm) 

455 

500 

550 

700 

835 

Table 22.--Rayleigh scattering coefficients for air, CO 2 , argon, 

and FI2 at T = OoC and P = 1013 . 25 mb 

Air CO 2 Argon _ Fl2 

(x 10- 5 m 1 ) (x 10- 5 m- 1 ) (x 105m 1) (x 10- 5 m- 1 ) 

2.665 6.956 2.34 40 . 8 

I. 810 4.724 I. 59 27 . 7 

1.226 3 . 200 1.08 18.8 

0.4605 1 . 202 .405 7.05 

0.2259 0.5896 .199 3 .46 

4.7 Urban-Rural Solar Radia tion Heasurements at St. Louis 

Simultaneous measurements of incident solar radiation from six locations in 

metropolitan St. Louis, Mo., have been analyzed. The mea surements, part of the 

EPA-sponsored Regional Air Pollution Study, were taken continuously from September 

1975 through ~Iarch 1977 with pyranometers having all-wave and 395 -nm and 695 -nm 

cutoff filters. The objective of the study was to document typical urban-rural 

variations of incident solar radiation . The work was sponsored by the U.S . 

Department of Energy through an interagency agreement with ARL/NOAA. A discussion 

of preliminary results and experimental design was given in last year's Summary 

Report (section 4.4). A report de sc ribing the complete analysis is also available 

(Peterson and Stoffel, 1979). 

80 
Atmospheric pollutants over the center of metropolita n St. Louis reduced 

incident all -wave solar irradiation by about 3% . Differences between urban and 

rural irradiation wer e about 1% greater than average during winter and 1% less 

than average i n s ummer . At two suburba n sites, the irradiation depletion averaged 

1% and 2% for summer and winter seasons , respectively. Under all conditions the 

ratios between stations for the complete experiment were similar to those for 

cloudfree conditions. Thus, any variations i n cloudiness over the network evidently were not s ufficiently large to affe ct the grand average irradiation 

distributi on over the network. 

Although the comparisions were stratified accordi ng to wind direction and 

speed, visibility, time of day, and day of the week , only wind direction had a 

s ignifi ca nt effect on the interstation ratios . For cloudless days two s ubu rba n 

s ites and a rural site north of the city received about 3 .5% more relative 

i rradiation with north than south ' winds . The explanation fo r t his wind direction 

effect is that pollutants were adv ec t ed from major sources near the city center. 

The two urban sites exhibited only about 1% change due to north-south wind 

differences . The interstation comparison s for all days during the complete 

experiment were also partitioned by wind direction. With north wind s, the 

s uburban and northern rural s ites s howed about 2% to 3% more relative irradiation 

on all days than on c l oudless days for bo th the s ummer period a nd the complete 

experiment. 

4.8 Cooperative U.S .A. -U.S . S . R. Atmospheric Transparency Meas urements 

Und er the U. S.A.-U.S . S.R . Agreement on Cooperation in the Field of Environmental Prot ec tion, Working Group VIII was established to develop cooperative 

projects that will increase und erstanding of the sensitivity of climate to 

natural a nd a nthrop ogenic environmental changes. One projec t of Working Group 

VIII included a joint program t o compare atmospheric transparency values derived 

from the use of U.S.S . R. and U.S. instruments. Some results of those compa risons 

and meas urements of atmo spheric turbidity are described here . Additional information i s presented in Peterson and Kovalyev (1979). 

Intensity of the direct solar beam was meas ured from Augu st 14- 23 , 1978, at 

Voeikovo i n the Soviet Union, an experimenta l site of the Main Geophysical 

Observatory, about 2S km east of Leningrad, in gently rolling , rural terrain. 

Atmospheric transparency (P) wa s det e rmined from me as urements of direct so l ar 

beam intensity (I A) at wavelength A from the following expression: 

1 

PA = (lAl lA )m 

o 

where IA is the so lar intensity above the atmo sphere and m is optical air mass. 

The U.S . instrument, operated by J. Pete rson of GMC C, was a po rtable Volz sunphotometer that uses narrowband filters wi th maximum transmissions at 380 - and 

SOO-nm wavelength (Flowers et al., 1969) . Soviet measurements during the compari sons were take n with an M-B3 instrument that is used routinely at some 30 

lo cations in the U.S.S.R. to measure the direc t solar beam in na rrow wavelength 

intervals to obtain total atmospheric ozone values and atmospher ic transparency 

at six wavelengths . The 369- and S30 -nm wave length measurements were used for 

these intercomp a risons, 

81 
035 I . I 

030 L - Leningrad Center 

~ 025 ~ 

> 

~ 0.20 

:0 

5 

~ 015 .£ 

'i. 0 0.10 

E 

.;t 0,05 ~ 

M - Main Geophys Din 

C leningrad CHy limits 

V - Voelkollo 

SOO"m 

380nm 

. . . : :.: . 

. . 

.. 

-='-u 

Observations 

Thr~~h2HuS 

.. : 

.. ~ =: 

.. "\ :: 

--~ > 

Sma!! Cumulus 

Form~ 

o~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ ~.~~~~~L-L-L-LJ 12131415 1617 1812 13 1415 1617 18 19 9 10 11 12 13 14 1516 17188 9 1011 12 13'1415161718191617 1818199 1011 12 

8 - 14 8-15 8- \6 8 - 17 8- 20 8- 2 1 8- 22 8- 23 

Figure SO . --Atmospheric turbidity mea surements at 380- and SOO-nm wavelengths 

in the vicinity of Leningrad, during August 19 78 . 

Value s of atmospheric transparency from the two instruments generally 

agreed well. After correction for wavelength differences, the two instruments 

meas ured atmospher i c transparency within about 2% of each other; much of this 

discrepancy probably resulted from instrume nt aperture differences . The M-8 3 

ha s an apera ture of 6° whereas the s unphotomet e r has an aperture of 1° 51', A 

complete report of these intercomp arisons is planned i n the Sovi e t literature . 

Besides the measur ements at Voei kovo, t he Volz sunphotometer was used 

pe riodical ly to obtain atmospheric turbidity (aerosol optical thi ckness) from 

the center of Leningrad and at the Main Geophysical Observatory (MGO). MGO is 

locate d i n a s uburban area about 10 km northeast of the city center. For the 

turb idity meas urements pre s ented in f ig . 50, values are expressed in the cus tomary 

decadi c ba se , and time is Leningrad loca l time (sta ndard time adva nced one 

hour), G~IT + 3 h. On August 16, 17, and 23, urban turbidities were noti cea bly 

greater t han the non-urban readings. On August 15 the non-urban values we re 

greater. On this day westerly winds advected c l ean air from the Gulf of Finland 

over the ci ty whereas Voeikovo was downwind of the urban industrial area. (The 

ci ty cente r is only a few kilomet e rs from t he Gulf . ) For 8 days with urban 

turbidity meas urements, average daily SOO -nm turbidity was 0.086. This value is 

simila r to s ummertime averages at many western U.S. locations (Flowers et al., 

1969). Turbidity varied over a fairly wide ra nge, however. On August 14 and 15 

the a tmosphere was quite clean, following a strong cold frontal passage and rain 

on the 13th . Turbidity averaged about 0.03. In contrast, on the la st day of 

meas ureme nts average urban turbidity exceeded 0 . 2 . 

4.9 Mt. Kenya Site Survey Evaluation 

During 1976 and 1977 the United Nations Environmental Program (UNEP) a nd 

the World eteoro logical Organization (\"1'10) sponsored a program t o assess the 

feasibility of Mt. Kenya, Kenya, as a site for baseline measureme nts . Several 

expeditions were undertaken to measure CO 2 , Aitken nuclei, and surface me teorolog -

ical cond itions at several lo cations on the mountain, all above 10,OOO-ft elevation and several as high as 14, 000 ft . In February 1978, G~ IC C was requested by 

82 
318 

Mauna Loa, HawaII 

May, 1975 

X -326.56 

IT 0.54 

N= 720 

C02 Concentration (ppm) Scripps 1957 Index Scale 

330 

Figure 5 1.--Histogram of hourly CO 2 

concentrations during May 1975, at 

Nauna Loa Observatory, Hawaii. Each 

bar represents the number of values 

within O.2-ppm intervals. Data are 

given on the Scripps 1957 index 

scale . 

Wl'lO a nd UNEP to assess the Mt. Kenya measurements to evaluate the suitability of 

the area for a baseline monitoring station. Subsequentl y, a report (sununarized 

here) was prepared (Peterson and Hanson, 1978) and transmitted to the Mt. Kenya 

Advisory Group for t heir co nsideration. 

The assessment foc used on analyses of CO 2 data and intercomparisons from 

three locations, Mt. Kenya, Mauna Loa, and Barrow. Almost all the Kenya CO 2 

data showed a diurnal cycle. Vegetative photosynthesis takes up CO 2 during 

daytime whereas respiration during the evening gives off CO 2 , Beca use of the 

usual tropical convective activity, ground-level vegetation affected CO 2 concentrations for a considerable height into the troposphere. A few tlONEX aircraft 

measurements over the Indian Ocean indicated significant variability of midtropospheric CO 2 in the Nt . Kenya region. The 31 over-ocean measurements on 

June 28 and 29, for example, had a mean of 328.7 and standard deviation of 0.83 

ppm. If this tropospheric variability is common over the tropical Indian Ocean 

upwind of Mt. Kenya, it would be unrealistic to expect extended periods of 

steady concentrations on the mountain like those found at Nauna Loa Observatory. 

One of the Kenyan CO 2 measurement series with least variability was that at 

Timau Hill during August 1978. Eighty-six CO 2 measurements "ere made with an 

overall mean of 328 . 7 and standard deviation of 1.66 ppm. If the measurements 

are assumed to be from a normal distribution, the computed 95% confidence interval about the mean is ± 0.35 ppm. Thus, there is only a 5% chance that the true 

mean CO 2 concentration at Timau Hill during this period was outside the interval 

328.7 ± 0.35 ppm. 

Two examples of Mauna Loa CO 2 measurements 

variability of the record at that observatory. 

of hourly CO 2 measurements at Mauna Loa for May 

Each bar represents the number of values within 

83 

were presented as a guide to 

Figures 51 and 52 are histograms 

1975 and May 1976, respectively . 

a 0 . 2-ppm interval. The monthly 
320 

Mauna loa. Hawaii 

May 1976 

327 18 

(T = 107 

697 

322 324 326 328 330 332 334 

Scripps 1957 Index Scale C02 Concentration (ppm) 

336 338 

Figure 52.--Histogram of hourly CO 2 concentrations during 

May 1976, at Mauna Loa Observatory , Hawa ii . Ea c h bar 

represents t he number of va lues within 0 . 2-ppm intervals . 

Data are given on the Scripps 1957 index scale. 

mea n (i), sta ndard deviation (a), and number of hourly measurements (N) are 

give n in the legend. During May 1975, rela tive ly littl e vari abi lity can be 

seen, whereas during May 1976 the variability was quite large. The sta ndard 

deviations vary by almost a factor of 2 between the months. Even though large 

variabi lity occurred during ay 1976, the majority of the measur ements fell 

within a 2-ppm range . The l owest readings proba bly corresponded to afternoon 

upslope airfl ow depleted of CO 2 by vegetative photosynthesis. The highest 

values probably occurred when nighttime downslope flow brought volcanic gases 

from the summit of the mountain. 

CO 2 data were also presented from the Pt. Barrow, Alas ka, baseline sta tion. 

The within-year variability of average daily CO 2 concentrations at Pt . Barrow is 

greater than that at any other U.S . baseline station and most resembled the 

Kenyan daLa. Average concentrations during late winter and spring are about 13 

ppm greater than those during August . During late summer , daily average concentrations range over about 5 ppm with individua l hourly values ranging over about 

10 ppm. 

Daily average CO 2 concentratio ns at Barrow from day-of-the -year (DOY) 129, 

1976, t hrough the end of 1977 are presented in fig. 53. Several typical features 

of the Barrow CO 2 record are evident. First, t here is an annual cycle of about 

12 ppm. Second, there is an annual cycle o f the day-to-day variability . The 

record from about DOY 25 -1 75 is quite smooth. There are several periods of some 

10 cons ecutive days where the range of daily average concentrations i s less than 

1 ppm . In contrast, from about DOY 200-290 day-to-day variability of a bout 

5 ppm is common. From DOY 290 through the end of the year there are both steady 

periods and times of daily variation of a few ppm. Third, the 1977 data are 

ap proximately 1 ppm greater than corresponding 1976 meas urements. These changes 

are presumably part of the global anthropogeni c CO 2 increase. Fina lly, during 

s ummer there is the suggestion that the l owest daily averages form an e nvelope 

84 
J.')-

, 50 

l3Jf")~ 250 

~ o 

<.? 33 

8 

" - --- 50 

" 250 

00'( 1970 >0, 

00'( 1976 300 

DOY 1977 >0, 

--'-

00'( 1977 '00 

150 

350 

>So 

35' 

Figure 53.--Dai l y average CO 2 con centrations at Pt . Barrow, Alaska, for 

1976 and 1977. Data are given on 

the Scripps 1957 index scale. 

representing regional ba ckground conditions for that place and time, and that 

the higher daily values include some measurements of nonbackground air. Within 

the summer season at Barrow we have a poor understanding of the air-Iand-vegetation- water -i ce CO 2 interactions in the Barrow and adjacent polar region s . There 

is also increased human activ ity du r ing su mmer around the settlement southwest 

and wes t of the observa t ory . These compl ex l ocal factors ma ke it difficult to 

separate the hemispheric s~aso nal decrease from local effects. However, selection 

of t hose days with sma ll within-day variabili t y a nd those hours when wind directio() was from the clean- air sector (00 to 120 0 ) yielded a measure of background 

c onditions largely fol l owing the envelope of l owest values discussed above. 

The conclusion drawn from this exercise was that although the summ ertime 

Barrow CO 2 record does have extensive variability, mea s urements representing 

background conditions could be selected out of the full data set based on meteoro -

logical criteria and / or hour-to-hour variability. Similar meteorological and 

statistical concepts neede d to be applied to the Kenyan data to show that peri ods 

of background conditions could be identified and that background CO 2 levels 

could be estimated with small un ce rtainty. In addition, typical meteorologica l 

regimes, both on a local scale (e.g., upslope-downslope) and regional s cale 

s hould be identified and typed. As such, we recommended that a broad meteorolog -

ical program including trajectory analyses be i ncluded in the Kenyan program. 

4.10 Trends in Atmospheric Transmission at Mauna Loa 

Ellis and Pueschel (1971) and Mendonca et al. (1978) have reported on the 

l o ng -term variations in atmospheric transmissions de t ermined f rom normal incidence 

irradiance measurements at Mauna Loa . Secular variations greater than a year 

have been observed and attributed to ejections of volcanic debris to stratospheric 

heights. Years are required for volca nic debris to be removed from the atmosphere 

depending on the quantity ejected, the location of the ejection , and the natural 

cleansing mechanisms. 

85 
Figure 54 shows the major departures from the 20-yr monthly averages in atmospheric transmission measured at Mauna Loa. The decreases in transmission in 

1963, 1966, 1974, and 1979 follow the major eruptions of Mt. Agung, Awu, De Fuego, 

and Soufriere, respectively. The gradual decrease in transmission from 1969 to 

1974 is unexplained; however, explosive volcanic activity during this period was 

primarily centered at latitudes greater than 50°. Whether an accumulative 

effect of the debris from these high latitude eruptions is associated wi th the 

gradual decrease in average transmission for this period must still be explored . 

The transmissions during winter 1977 a nd 1978 are some of the highest o b served 

in the 20-yr record. The measured transmissions during 1977 and 1978 reac hed 

the levels of the pre-Agung period and recovered from t he secular attenuatio n s 

in transmissions which started with the Agung eruption in 1963. During 1977-78, 

Northern Hemispheric circulation patterns in winter over Mauna Loa a ltered, and 

storm tracks over the Eastern and Northwest United States changed to produce 

severe winters in the East and droughts in the Northwest. 

Table 23 lists the monthly average atmospheric transmissions for Mauna Loa 

Observatory for the 20-yr period. The transmissions are obtained from daily 

meas urements of normal incidence solar irradiances under clear-sky conditions at 

secant zenith angles of 5, 4, 3, 2 . 

~ 

v 

~ 

ro 

~ > 

~ 

~ 

~ C 

0 

~ 

v 

£ 

E 

0 

~ 

~ 

v 

5 

ro 

~ 

v 

0 

0 

N 

0 

d 

~ 

0 

d 

0 

0 

0 

~ 

0 

~ 

0 

0 

g 

~ 

0 

0 

ci 

c 

0 

~ 

~ 

0 

d 

o 

N 

o 

0 

N 

0 

d 

~ 

0 

d 

~ 

~ 

~ 

0 

0 

d 

0 

0 

~ 

~ 

0 

~ 

0 

~ 

~ 

0 

d 

, 

~ o 

d 

, ~9~'~B~'~9~'9~'~9~.O~~'9~.~'~'~9~.2~'~9~.3~'~9.~'~'9~.~'~'9~.~.~'9t..~7~'9~.~B~'9~.~9~'9~7~O~'9~7~'~'~9~72'-'~9~73~'~9"7'~'~97~'~';97n.~';97~7~'9t7"8~'9t7"9~ 1980 

Year 

~ 

v 

~ 

ro 

~ > 

~ 

~ 

~ 

C 

0 

~ 

v 

£ 

E 

0 

~ 

~ 

v 

5 

~ ~ 

v 

0 

Figure 54.--Plot of the Mauna Loa tra nsmission departu res from the composite 

monthly averages for al l years. Departures are t he differences be tween transmissions for individual months and mean transmission o f t he same months, i . e . , 

Jan 1958 transmission minus Jan mean, Feb 1958 transmission minus Feb mea n, e t c. 

86 
Table 23. --Average apparent solar irradiance transmission (i)* at Mauna Loa Observatory 

Year 

1958 

1959 

1960 

1961 

1962 

1963 

1964 

1965 

1966 

1967 

1968 

1969 

1970 

1971 

1972 

1973 

1974 

1975 

1976 

1977 

1978 

1979 

Jan 

.936 

.938 

.936 

.937 

.934 

.933 

.921 

.919 

.926 

.926 

.929 

.9 31 

.937 

.937 

.930 

. 937 

.932 

.928 

.924 

.941 

.938 

.937 

Feb 

.933 

.936 

.934 

.931 

.936 

.935 

.918 

.914 

.929 

.922 

.929 

.924 

. 935 

.9 33 

. 934 

.931 

.929 

. 928 

. 932 

.938 

.941 

.933 

.'. T = ~ . (t! + t: + 

Mar 

.933 

.934 

.935 

.934 

.929 

.934 

.913 

.917 

.922 

.923 

.928 

.926 

. 930 

.930 

.932 

.930 

.926 

.93 1 

.935 

.935 

.927 

Apr 

.929 

.934 

.924 

.933 

.930 

.926 

.909 

.915 

.921 

.9 16 

.923 

.931 

.931 

.927 

.927 

.918 

.932 

.925 

.929 

.921 

Monthly averages (a.m. values) 

May 

.930 

.935 

.928 

.933 

.928 

.909 

.908 

.912 

.919 

.918 

.923 

.931 

.928 

.924 

.924 

.924 

.922 

.924 

.932 

.928 

.922 

Jun 

.931 

.930 

.925 

.9 30 

.933 

.920 

.918 

.914 

.92 2 

. 922 

.922 

.929 

.927 

.928 

.930 

.938 

.929 

.927 

.934 

.926 

.931 

Ju] 

.933 

.931 

.936 

.934 

.9 36 

.922 

.917 

.920 

.929 

.919 

.925 

.934 

.934 

.931 

.930 

.937 

.931 

.926 

.930 

.933 

.932 

Aug 

.933 

.936 

.933 

.936 

.932 

.920 

.915 

.925 

.932 

.926 

.925 

.931 

.934 

.934 

.935 

.930 

.929 

.930 

.922 

.932 

.928 

.931 

Sep 

.934 

.934 

.938 

.934 

.936 

.919 

.915 

.922 

.923 

.920 

.927 

.930 

.932 

.934 

.931 

.931 

.931 

.928 

.932 

.930 

.937 

OCL 

.935 

.936 

.934 

.932 

.937 

.921 

.917 

.923 

.920 

.926 

.927 

.928 

.932 

.937 

.927 

.937 

.934 

.929 

.935 

.935 

.930 

Nov 

.933 

.935 

.937 

.936 

.935 

.923 

.913 

.925 

.923 

.924 

.929 

.930 

.933 

.934 

.931 

.931 

. 930 

.928 

.933 

.937 

.934 

average apparent solar irradiance transmission, 

Dec 

.935 

.937 

.935 

.937 

.936 

.925 

.918 

.925 

.924 

.926 

.929 

.929 

.935 

.930 

.936 

.933 

.932 

.931 

.939 

.936 

.934 

I 

n measure o f normal illcidence irradiance at ll n at sec Z n, and n = integers 5 to 2. 

**Average for 1970-1974 (data missing [or these months). 

4.11 Smithsoni an Radiation Data Evaluation 

The Astrophysical Observatory of the Smithsonian Institution (APO) measured 

the solar co ns tant on the Earth's surface from 1902 to 1962. Hoyt's report 

(1979a) dis c u sses a lack of consisten cy in the APO solar constant measurements 

resulting from the lack of a common signal between stations or bet\o.'een measurement 

methods . When the overall data set was considered, there was no evidence for 

cyc li c variations or any long-term trend in the solar constant greater than a 

f ew tenths of a p ercent . Overall, the solar constant appeared to be constant to 

within about 0.1% over the period 1923 to 1954. 

87 
Hoyt (l979b) examined the pyrheliometric and circumsolar sky radiation 

measurements of the APO, especia lly those for Nt. Mont ez um a, Chile, and Ta bl e 

Hountain, Calif . , for volcanic effec t s . Paluweh (8° 19' S , 12 1°42 ' W) , which 

erupted i n 1928, was fo und to h ave a dust veil i nd ex of 100. Qui zapu (35°39' S , 

70°46' W), whi ch erupted i n 1932, ha d a dust veil index of 35 . Both vo l cani c 

eruptions were identified in the APO record and were thought to be climatologi -

cally signifi cant . 

Using the pyrheliometric mea s ureme nts o f the APO, the re lative atmospheric 

transmission was calcul ated at four locations during the period 1923 to 1957 . 

Decreases i n atmospheric transmission caused by t hree major volcanic eruptions 

are evident in t he Mt. ontezuma , Chil e , records. For those vo l ca ni c eruptions 

in the tropics , the transmission a lso decreases a t Table Mountain , Calif. 

A persistent annual cyc l e in apparent atmospheric transmission found in 

the APO data set was thought to b e caused by variations i n total precipitable 

water and aerosol loading. No long-term trend in total precipitable water was 

found at the APO sites although there is a l arge year-to-year variability. 

4.12 Solar Variabi lity and Climate 

Hoyt ( 1978) mad e a simpl e mode l of the time variation of the solar co nst a nt, 

ass uming that sunspots block radiation and faculae add to the solar constant . 

In this model an 11 - yr cyc l e app ears afte r 1940 but never exceeds 0 . 075% . Th e 

results of the mode l demonstrate that the physical mech anism of perturbations to 

the solar constant by active features on t he Sun i s probably not a s i gnifica nt 

sour ce of climati c variation. 

Hoy t (1979c) d escribed sunspot structure b y taking the rati o of the area of 

the umbra to that of the penumbra . The time dependence of this umbr al/penumbr a l 

ratio is similar to t he record of Northern Hem isphere s urfa ce temperature anoma -

lies. On a year-to-year basis the correlation is 0.57, which is significant at 

better than the 0.01% l evel. The umb ral/penumbral ratio can b e used as a meas u re 

of convective flux in the Sun and hence solar luminosity. Using theoretical 

models for s unspot structure and convection , one ca n deduc e that the observed 

changes in t he umbral/penumbral rat io over the last century correspond to changes 

in the solar constant of 0 . 3 to 0 . 4% . 

4.13 Trends in Atmos pheric Transmission in the United States 

The pyreheliometric measurements a t three locations in the United States 

were exami ned to determine if there were trends in a tm ospher ic tra ns mission 

(Hoyt et al., 1979). Although the radiation values at Hadison, Wis., were 

depressed in the 1940's because of lo ca l pollution, no strong evidence of other 

anthropogenic aerosol pollution was seen at Madison , Albuquerque , N. M. , or 

Blue Hill , Hass., from 1940 to 1977 . There is a s u ggestion o f increased aeroso l 

pollution for the three sta ti ons, but the decrease in atmospheric transmission 

is rather small. The radiation records give evide nce for the eruptions of 

Agung, Awu , a n d Fuego. The erupti on of Agung increases the opti ca l depth by 

about 0.035 several mo nth s after its eruption. By 19 65 the a tmospheric transmission returned to normal . 

88 
5. COOPERATIVE PROGRANS 

5 .1 Aerosol Climatology of the South Pole 

A. Hogan, S. Barnard, and J. Samson 

State University of New York at Albany 

Albany, NY 12222 

Cooperative aeroso l meas ur ements by Atmospheric Sciences Research Center 

(ASRC), GMC C, and other observers began at the old Pole stalion in January 1974. 

ASRC provided a Pollak counter to standardize the GNCC G.E. condensation nucleus 

counter; in return , G~ICC agreed to make and log Lwo readings of outside aerosol 

concentration wit h the Pollak counter each day for ASRC. One observation is 

made at about the time o f the radiosonde ascent; the second is made when convenient, at l east 8 h removed. Wind direction and velocity, temperature, barometric 

pressu re , and l ocal weather are noted at the observation time. In 1976, the 

output of the electrolyti c water vapor detector was added to lhe ICDAS record. 

Several sizing techniques have been employed over the years, including the Rich 

diffuser-de nuder, the Sinc l air diffusion battery, and the Spurny Nuclepore 

method. 

The Pollak counter was calibrated just before shipment to Antarctica in 

fall 1973. One month later, the ASRe standard was found to agree well with the 

Minnesota standard, and one year later it agreed well with several other instruments at NCAR. Although the instrument has not been recalibrated since it was 

s hipped to the Pole, an identical instrument was recently recovered from 6-yr 

field se r vice in Hawaii and was found to repeat its initial calibration. The 

instrument at Antarctica has performed reliably \\Iith only routine maintenance 

and ins pection. A 2-mo period of data (July to August 1975), suspect because of 

an inlet l e ak discovered l ater, is the only flaw in the record . 

The Pollak counter and t he water vapor detector are exposed through the 

large GflCC me tal inlet stack in t he CAF. This exposure has proved to be excellent; a f ew instances of station contamination do occur each year, but are 

e asily pred i c t able from the meteorological record . No corrections or deletions 

have been applied to the reported data . 

5.1.1 Results of Experiments 

Seasonal Variation in Total Aerosol Concentration 

A very large seasonal trend in aerosol concentration was readily apparent 

from initial observations. An extensive series of measurements was made during 

September-October to identify trends in aerosol concentration accompanying the 

reappearance of the Sun. Several periods of increased aerosol concentration 

appeared after sunrise, and summer minima did not approach winter (darkness) 

minima. We hypothesized that these aerosol events could be the result of photochemical aerosol production or enhanced mixing of the lower layers accompa nying 

the weakening of the winter inversion. Since that time we have attempted in 

several experiments to produce aerosol particles from vapors in Antarctic air. 

We have not been able to produce particles during day or night by using ultraviolet light or strong oxi dan t vapors (iodine). We can , however, produce particles 

in summer with terpene (limonene from orange peel) vapors . These experiments 

indicate that enhanced summer aerosol concentrations result from enhanced mixing 

rather than photo chemi ca l production of aerosol. 

89 
+ 

TE MPERATU RE 

~ ----=l,9 '1..,..0 , C 

!I , 

" 

.J 0 

~ 

--,----

MIXING RA TIO 

+ 

FREaU EN CY 

, 

! 

, , , 

WIN O SPEED 

, 

! 

, 

N UCl EI 

~ __ ' 

\ 

" 1 

, 

Figure 55. --~1ean values of temperature, wind speed, wa ter vapor, mixing ra tio, 

and Aitken nucleus concentrations observed concurrently at South Pole 

during the sunlit months, Oct - Mar. Frequency of wind direction occurrence is shown with the origin of the graph superimposed on the station 

location on the map. 

Meteoro l ogical Variation in Aerosol Conc entrations 

Surface winds at the South Pole are predominantly from the northeast quadrant 

(north being defined he re as the Gree nwich Meridian). Storm winds are generally 

from the northwest, and bright clear days occur with winds from east to southeast. 

The camp is south of the eAF , but winds from this direction occur less tha n five 

times per yea r . 

Previous experiments showed that the greatest concentrations of larger 

parti c les arrive with mo ist storm winds from the northwest. Great concentrations 

of very small particles occur in strong subsidence following frontal passage . 

An attempt was made to stratify the 4 yea rs of summer and winter data by wind 

direction . The variations in aerosol concentration, water vapor mixing ratio, 

temperature, and wind spe ed are shown in figs. 55 and 56, plotted as a function 

of wind direction by 20° increments. Wind direction is most frequently from the 

northeast quadrant as previously reported, with only 17% of winter winds and 18% 

90 
1 

, 

/ 

I 

+ 

+ 

./ 

+ 

TEMPER A TURE 

-+-

-+-

-+-

-+-

t 

FREOUENCY 

I) 

WINO SPEED 

-----_ I , + >------;-' 1\ MP , 

I , 

- , 

, 

NUCL EI 

Figure 56.--Similar to fig. 55 but for the winter months, Apr - Sep . 

of summer winds from outside this sector. The 010 0 to 0300 sector is favored 

(21% of total) in winter, but all sectors of the northeast quadrant receive 

equal fractions of the total winds during swnmer. The fastest (15 kt mean 

speed) winter winds are also from the 0100 to 039 0 sector . 

The temperature wheels show a smooth decrease in temperature with increasing 

easterly component of wind in winter and a less marked decrease in summer. ~fost 

striking is the decrease in water vapor mixing ratio as the wind vector swings 

from northwest to southeast. 

The number of aerosol particles is also at a maximum with winds from the 

northwest in winter and summer . A very strong decrease in aerosol concentration 

occurs with increasing eastward wind component in winter, but mean concentrations 

are mor e equally distributed from north t o southeast in summer. 

We propose a relatively simple explanation for these phenomena. When 

strong high pressure is present over east Antarctica, a blocking of circulation 

occurs which prevents air from the Weddell Sea area from reaching the Polar 

Plateau. When a high is centered between the Weddell Sea and the Polar Plateau 

(i.e., north of the station) a very short path from open water to Pole is available, and warm moisture- and aerosol-laden air reaches the station. As the high 

91 
Table 24.--Number of observations (N) and monthly mean aerosol concentrations 

(2 cm- 3 ) at Amundsen-Scott South Pole Station 

Old Pole CAF 111 CAF 112 

Nonth 1974 1975 1976 1977 1978 

N Z cm- 3 N Z cm- 3 N Z cm- 3 N Z cm- 3 N Z cm- 3 

Jan 25 103 43 138 48 119 62 254 

Feb 6 85 56 109 42 226 48 159 56 188 

Nar 22 349 91 119 72 140 62 120 84 121 

Apr 22 109 85 47 56 57 54 44 102 30 

~Jay 4 29 61 24 60 49 62 31 93 20 

Jun 13 29 57 13 58 W' 59 22 90 7 

Jul 49 23 59 12 61 W' 62 15 93 10 

Aug 19 53 63 16 62 15 62 16 91 9 

Sep 94 48 57 36 83 37 60 43 90 27 

Oct 56 117 40 99 61 124 62 178 93 79 

Nov 23 159 25 254 55 364 56 169 80 172 

De c 1 89 41 131 32 121 57 161 53 154 

~Jean 82'" 68 W' 88 76 

;'N = missing concentration . 

center is displaced eastward the trajectory from open water increases, and more 

heat and water vapor are lost to the ice cap before the air arrives at the Pole. 

The discrepancy in rate of decrease in temperature and water vapor with respect 

to aerosol concentration indicates that at low concentrations aerosol is removed 

quite slowly as it approaches its end-point concentration . 

Trends in Antarctic Aerosol Concentration 

The monthly mean concentrations of aerosol observed at South Pole are 

tabulated in table 24. There is no discernible trend in either sununer or winter 

concentrations . November has the highest mean concentration in nearly every 

case, and June, July, August, and early September are repeatedly quite low . 

5.1.2 Conclusions 

Aerosol data for 5 years from South Pole show a distinct seasonal trend but 

no secular trend. There is a slight tendency for aerosol concentrations to 

decrease with increasing easterly component of surface winds. These findings 

should be evaluated in future searches for secular trends. 

Aerosol concentrations appear to decrease at a less rapid rate than water 

vapor and air temperature with increasing path length from open water . This 

rapidly decreasing rate in aerosol concentrations can be interpreted as an end 

point in aerosol removal mechanisms . The aerosol concentrations measured under 

these conditions are assumed to be asymptotically approaching a minimal level in 

the Arctic. 

92 
5.2 Chemistry of Antarctic Aerosols at the South Pole 

William H. Zoller 

University of Maryland 

College Park, ~lD 20742 

Atmospheric particulate material has been collected at the South Pole for 

four austral s ummer seaso ns and t\vO winters since 1970. With R. A. Duce of the 

University of Rhode Islaud, we ha ve tried to i dentify the sour ces of Antarctic 

aerosols by their chemical composition. During the austral summers the samples 

were collected at the remote site 5 km northeast of the South Pole Station to 

minimize contamination from the station. 

The first summer sampl es were collected in November and December 1970, as 

part of Operation Deep Freeze (DF 71), upwind of the old Pole station, and the 

findings have been published by Zoller et al . (1974). Samples that were collected during DF 72 to 74 were badly contaminated by construction. During 

December 1974 and January 1975, a very good set of samples was collected at the 

new site (5-km altitude) as reported by Maenhaut and Zoller (1977) and Maenhaut 

et a1. (1979a, 1979b). Additional austral summer sampl es were collected during 

DF 76,78 and 79 at the remote site and at the CAF during DF 78 and 79. The 

samples for DF 76 and 78 ha ve been analyzed so that data are now available for 

four summer seasons . 

Severe weather conditions preclude the use of the remote site after the 

temperature drops below -45°C. For this reason, the overwinter samp les have 

been collected at the CAF with t he help of the winter-over NOAA personnel present. 

Samples for winter 1975 were collected by G. Engeman and S . Kott at the temporary 

under-snow facility. These samples suffered some contamination but yielded 

usable data for many elemen ts. The winter 1976 samples were collected by V. 

Szwarc and J. Jordan at the same facility after modifications to the sampling 

system. C. ~lcGregor overwintered in 1978 and collected samples at the new CAF; 

these are being analyzed. 

The samples are collected by pulling large volumes of air through filters 

t·dth a vacuum pump. Care is taken to minimize contamination, and a wind -

directional controller is used to turn the pumps off if the wind direction 

changes so t hat the station could contaminate the samples. Each sample returned 

is counted with y-ray detectors to meas ure natural radioactivity, such as 7Be, 

and fission products from nuclear tests (Maenhaut et al . , 1979b ). These radionuclides are good tracers of different air masses and tran sport phenomena . Neutron activation analysis and atomi c absorption are used t o mea s ure as many trace 

elements as possible on each sample. (For details of the analytical work on the 

samples and blanks, see Maenhaut and Zoller, 1977 , and Maenhaut et al. 1979a.) 

The results of the chemical analyses are interpreted by comparing the 

elemental distributions patterns of the two dominant sources of atmospheric 

particulate material in remote areas. To identify elements associated with each 

source and estimate the relative importance of each to the South Pole aerosol 

burden, the marker elements Al and Na were chosen to represent the crustal and 

oceanic material. By comparing them with the composition of average crustal 

material (Taylor, 1964) and of sea salt (Brewer, 1975), the observed elements 

are divided into the following three groups (table 25) : crustal weathering, sea 

salt, and en riched or vo l atile elements. The elements with essentially the same 

distribution pattern as average crustal material are probably of crustal origin . 

93 
Table 25.--Elements observed at South Pole (DF 75) 

Crustal components : 

Sea salt : 

Volatile elements: 

AI, Sc, V, Fe, Mn, Th, Ti, La, 8m, Eu, ee, Lu, 

Hf, Co, Rb, Ta, Cs, Ba, (Mg, Ca, K, Cr)* 

Na, (Cl, I, ~lg, Ca, K) 

I, Br, el, 5 , Se, Cd , Ag, As , Au, Pb, Sb, W, 

In, Cu, Zn (Cr) 

;~Elements in parentheses have components from more than one source. 

Very little of the sodium is of crustal origin, and its most probable source is 

the ocean . 

Other e l ements a lso ha ve a significant oceanic component (table 25). The 

last group of elements is enriched in the South Polar aerosol far more than 

would be expected if their source were crusta l weathering or sea sa lt. The 

source of those elements is unclear, and has been discussed at length i n the 

literature (Zoller et al . , 1974; Maenhaut et al., 19 79a; Duce et al., 1975). 

The sulfur (as sulfate) is the most abundant element present. From the data 

from DF 75, it accounted for approximately 90% of the mass of the measured 

components whereas the crustal materia l and sea salt accounted for 4% and 5%, 

respectively. The sulfate is believed to be transported to the Pole through the 

lower stratosphere, since it corrp.lates well with 7Be, which is of stratospheric 

origin (Maenhaut et al., 19 79a). 

In this report, the results of the analyses of samples from four summer 

seasons and two over-winter periods are compared for the crustal and marine 

sources . The mass of crustal components ha s been calculated for each sample by 

assuming that all Sc, Al, and V arise primarily from the Earth's crust. The sea 

sa lt components were calculated by assuming that all Na not accounted for by the 

crustal component originated from airborne sea salt. Figure 57 shows the masses 

of the crustal and marine components for sampling periods. Table 26 gives the 

average mass loadings of crustal material and sea salt for each of the six 

sampling periods as well as the 7Be concentration. The most striking observation 

is that during the winter season the crustal component drops to about one fourth 

of its summer value, whereas the sea salt comp onent increases to about 20 times 

its summer value. 

E 

0> 

C 

Crust I 

10 -,_ -- < 

1-

Sea 

100 -

10 -" .--

I 

OF 71 

":.-...... -- - - ..... -- -

-. --:-:----

1975 

I 

--. :. -

----:-.. --

~- ----- . 

-. - -' 

I 

1976 

I 

-

'.-:. -

I 

OF 78 

94 

Figure 57.--Aerosol mass determinations 

for crustal and sea salt aerosol 

classifications at SPO. Samples are 

taken by high-volume filter sampling 

at the surface . Note annual variation in both aerosol classifications. 
Table 26.--Mass of atmospheric components and 7Be at SPO 

Crust (ng m- 3 ) 

DF 71 6.3±2.0 

DF 75 9.1±3.6 

DF 76 15±8 

DF 78 4.1+0 . 9 

Av. summ er 8.6 

1975 3.1±l.3 

1976 1.7+l.0 

Av . winter 2.2 

Sea (ng m- 3 ) 

7 .1±4.0 

3 . 1±0.9 

3. 1±2 . 3 

5.4±1.1 

4.7 

96±43 

100±60 

100 

198±24 

215±30 

205±50 

206 

69±1 

66±16 

68 

These observations mu st reflect a seasonal difference in transport of 

atmospheri c particulates to t he South Pole. Sulfate fol l ows the crustal component, 

but the decrease during the winter is not as large, being only a factor of 2 or 

3 , which is similar to t he change in 7Be. These results suggest that the crustal 

components and 78e are involved with a transport mechanism relating to the lower 

stratosphere and may be i ndi cative of long-range transport, whereas the sea salt 

enhancement and 78e decrease during the winter are correla t ed with some form of 

a tropospheric transport process. In t he winter, severe s torms surround the 

Antarctic continent, and probably enhan ce the airborne sea salt component in 

coastal areas . These storms could a l so transport the sea salt aerosols into the 

upper troposphere near the coast of the Weddell Sea and into the interior of the 

continent. 

More long-term monitoring of t he chemical composition is obviously needed 

to help evaluate both the sources and transport of a tmos heric aeroso ls to the 

South Pole . The chemi ca l comp ositions of the aerosols themse l ves identify them 

s o that changes in concentration or composition may be related to similar change s 

in sources. 

5 . 3 Individual Particle Analysis of Antarctic Aerosols 

Fa rn Pa rungo 

Atmospheric Physics and Chemistry Laboratory, NOAA 

Boulder, CO 80303 

Aerosol samples were collected on Nuclepore filters at the South Pole 

s tation during October and November 1977. The particl es were analyzed with an 

electron microscope for their morphology, size distribution, and concentration 

(fig. 58) . The chemica l comp ositions of individual particles were determined 

with an X-ray energy spectrometer as was the frequency of elements present in 

the particles (fig. 59). The results provide basic information on the physical 

and chemical properties of Antarctic aerosols as well as their source and journey. 

The following origins of Antarctic aerosol particles are suggested: surrounding 

oceans, Antarctic mountain ranges, othe r continents, meteors, volcanoes (specifically ~It. Erebus) , and the stratosphere (particularly for Aitken nuclei) . 

95 
100,---------------_. 

• 24 Nov. \977 

'" 101 I 

E 

OJ 

~')..\ • 25 Nov. 1977 I 

/ .. ", ~ .~ 

• \ 

75 

50 

25 

100 Tolal Particles 

o F NaMgAI Si P S CI K Ca Ti CrMn Fe Co Ni Cn Zn Au 

C 100 ~ 30 Giani Particl es 

a3 75 d? 2J.L m 

W 

~ 50 

:; 

~ 25 ~ 

F~Na]M;g~AI~S ibp~S~C I~K~C a~T~i~C}rM~nJF~e~C~o~N~i~cn~Z~n~A iJ M 

c 

o 

"0 Z~ -

"0 

10' 

\. 

\ 

'-' 

~100 r------------------------------------. 

u 

'E 75 M 

"" "0 50 

c 

~ 25 

30 Large Particles 

0.2,.,m d 2,., 01 

\. 

\ ~ F ~~~~~~~~~~LJ~~~~ NaMgAISi P SCI K Ca Ti CrMnFeCoNiCnZnAu ~ 

\ 

\ 

• 10·1L-_ _ ___ -c-_ ___ -,-_ _ "'-J 

10 2 101 10' 

100 

-

0-

75 

5 

25 -

-

.r 

40 Ailken Particles 

d· 0.2,.,m 

-

r1- I 0 F NaMgAI SI P SCI K CaTI CrMnFeCoNICuZnAu 

-

-

-

Part iete Diameter D (fLm) 

Figure 58.--Size distribution and con -

centrati on in SPO aerosol sampl es . 

Figure 59.--Frequency of e l ements present in partic l es collected at SPO. 

5.4 Monitoring of Large Atmospheric Particles 

at South Pole Station 

J. R. Petit 

Laboratoire de Glaciologie du CNRS 

Grenoble, Fran ce 

Ive are studying insoluble mi croparticles in the s now to determine s hortterm (seasonal) c hanges as a possible way to date ice core when other techniques, 

such as stable isotopes, cannot be applied. Possible correlations of micropartic l e content with climatic changes or volcanic events will be studied. 

The seasonal changes of mi c roparticle s are not a l ways c l early s hown i n the 

snow record, although t hey are generally assumed (Thomp son et al ., 19 75). The 

aim o f this project is to study a tmospheric micropartic l e concentrations measured 

near the surface to study seasonal changes a nd to help evaluate the interpretation of the s now data. 

To compare measurements of atmospheric aerosols with the data obtained from 

th e s now samples (determination of particles greater than 0.8 ~m ) a photoelectric 

96 
particle counter (Coulter 550) was used to measure particles greater than 0.5 ~m. 

This counter is generally used to monitor aerosol concentrations below 3,000 i 

of air. Although calibrations are regularly made, there may be some uncertainties in the obtained absolute value; however , relative changes with time, which 

are the mo st important for our purpose, should not be affected by these uncertainties. Because of the low concentration of atmospheric partic les, one measurement requires the analysis of about 10 m3 of air, obtained by pumping for 5 

hours. 

The first data were obtained over a period of 3 weeks during the 1977-78 

field season, by using t he CAF at the South Pole Stati on . The measured concentrations are in the range of 400 to 2,000 particles m- 3 STP; these values agree with 

the results obtained by Hogan (1977) with a similar aerosol counter (Royco). 

This program is being continued as a cooperative project with the NOAA/GHCC . 

5 . 5 Chemical and Optical Properties of the Barrow Aerosol 

Kenneth A. Rahn 

University of Rhode Island 

Kingston, RI 02881 

During 1978 the joint research program on t he chemical and optical properties 

of the Ar c tic aerosol by the Universities of Rhode Island (K. Rahn) and Alaska 

(G. Shaw) continued at Barrow . Continuous 3- to 4-day aerosol samples were 

taken with a high-volume filter sampler at the observatory. Trace elements such 

as vanadium were analyzed. In addition, techniques for determining sulfate and 

210Pb were developed by R. McCaffrey of URI and applied to the first 2 years 

of Barrow filters. 

Nonmarine sulfate showed unexpectedly high monthly mean concentrations of 1 

to 2 ~g m- 3 during winter, with a maximum of 2 to 2.5 ~g m- 3 in Harch. Individual sampl es va ried grea tly, wi th maxima approaching 5 lJg m - 3. In summer, ~o""ever J 

the co nc entrations were an order of magnitude lower, about 0.1 to 0.2 ~g m 3, 

This seasonal variation is very similar to that of vanadium noted in the 1977 

GNCC Summary Report. Figure 60 shows the monthly mean concentrations for nonmarine s ulfate and noncrustal vanadium at Barrow during 1976-77. The amplitude 

of the vanadium cycle is greater than that of sulfate for unknown reasons. 

The high concentrations of sulfate are significant. In winter, the concentrations of sulfate in midlatitude polluted regions, such as Europe or the 

Northeastern United States, are about 6 ~g m- 3 , only 3 to 4 times higher than at 

Barrow. In contrast, vanadium is 30 to 40 times more concentrated in midlatitudes 

than at Barroh'. Thus, sulfate is enriched relative to vanadium (and most of the 

other trace elements) at Barrow by an order of magnitude relative to midlatitudes. 

Sulfate is a major constituent of the Barrow aerosol, and its high concentration 

provides a clue to the explanation for the winter-long Arctic haze. As opposed 

to trace metals at Barrow, which are inevitably many times less concentrated 

than in midlatitudes, the sulfate concentration is only modestly reduced. 

The most likely source of this sulfate is midlatitude pollution S02' 

Marine sulfate has already been subtracted out; it accounts for half the total 

sulfate in summer but only 20% in winter. Subsidence from the stratosphere can 

97 
also be e l i mina ted beca use 7Be and 0 3 concent rations a t Barrow in winter are 

only 1% of their stratosp heric val ues ; reducing stra t osp heric sulfate by this 

same fac t or yields l ess than 0 . 01 g m- 3 . Volcanism is a possible source, but 

it is not clear why it should produce only a winter maximum of sulfate . At this 

time we ha ve no evidenc e that vo l ca noes should contribute significan tly to the 

Barrow s ulfate, a lthough this source cannot be exc luded. Biogenic sulfate 

should be a min i mum, not a maximum during the wi nter , and so can be e liminated 

as wel l. Midlatitude pollution sources are sufficient to account for the 

sulfate at Barrow. 

The 210Pb da ta from Barrow are interesting. 210Pb has be e n determined in 

filters from Barrow by the Environmental flea s urements Laboratory of New York 

City. Their data, as well as our s, show that concent rations of 210Pb at Barrow 

during winter are the highest o f any of their sampling stations. In particular, 

they are about two times higher than in t he Northeastern United States. During 

summer, however, 2 10Pb is 10 to 15 times l ess concent rated in Barrow, and is 

l ower than in the Northeast Un ited States . This high winter concentration 

agrees wi th the beha vior of s ulfa t e and va nadium (and the Barro,",,' aerosol in 

general); in fac t , ou r data for s ulfate and 2 10Pb from the same filters s how 

that the t wo have an extremely tight correla t ion. The hi gh absolute va lues of 

210Pb concentra tion are puzz ling, however, beca use they indicate t hat Barrow is 

twice as "contine ntal" as the Northeas t Unit ed States (210Pb i s derived from 

222Rn, which is exhumed from contine nts) , which is clearly not t he case . We 

feel that the great pa rallel between 210Pb and sulfate, both of whi ch are secondary aeroso l s (derived from atmosp heric gases rather than being injected directly 

into the atmosphere as aerosol) and are much mo re concentrated i n Barrow than 

expected, is no coincidence. It can be explained by continua l gas-to-par ticle 

z o 1.00 

I-

<t 

0:: 

IZ 

w 

<.> 

z 

o 

U 0.10 

EXCESS 

/' 

EXCESS V,' ng m-3 

0 .0 I '-:::~=-,"-:-:-,-="...L-.,-L-=-~...L-.,-L-:-:-~-'------'-:--'-:,-J 

SONDJFMAMJJAS 

98 

Figure 60.--Monthly mean concentrations 

of excess (nonmarine) sulfate and 

excess (noncrustal) va nadi um in the 

s urface aerosol at BRW, 19 76-1977 . 
5 

W 3 

Cl 

:::;) 

rr- 2 

-I 

« 

-- ~, 

510 

nm 

410 

nm 

I II II I 

001 

(3, 

RH 

'-'- 0 

01 

km- I 0 50 

RH, 

10 

100 

0/0 

Figure 61.--Vertical profiles of optical extinction coefficient ~ at three 

wavelengths, near Barrow, Nar 31, 

1978. Note general relation to relative humidity. 

production in the Arctic atmosphere coupled with abnormally long residence times 

during winter, so that secondary products can build up to very high concentrations before being removed. We presently estimate Arctic residence times during 

winter to be up to an order of magnitude longer than those of midlatitudes, or 

1 to 2 months or more. 

Support for the midlatitude source of the Barrow aerosol, followed by longrange transport and decreasing removal rates during transport, comes from a 

series of ca lculations which show that the concentrations of V, 210Pb, and 

s ulfate at Barrow in winter are quantitatively compatible with a midlatitude 

source, transport times of 15 to 20 days, dilution of the basic air mass by 

factors of about 6 during transport, and residence times which increase from 5 

to 50 days during transport. 

During March and April 1978 we performed a field experiment at Barrow, part 

of which was a series of four aircraft flights during which vertical profiles of 

haze were meas ured with a sunphotometer. The results of one of these flights 

are shown in fig. 61. They are typical, and show a major low-lying haze band a t 

about 300-m elevation and a secondary, broader band at 3000 m. Relatively clear 

layers are found at the surface, between the bands, and above the upper band. 

Our experience is that the haze layer below 1 to 2 km and the clear layer near 

the surface are reproducible features of the Barrow atmosphere during winter. 

It can also be seen from fig . 61 that maxima of haze correspond with maxima of 

relative humidity . This s uggests that Arctic haze is largely water condensed on 

hygroscopic nuclei, an explanation compatible with the high sulfate concentrations 

in the aerosol . ~licroscopic inspection of haze particles impacted onto a glass 

slide shows that they are dominated by colorless spheres, most having a radius 

less than 1 ~m. Our previous electron microprobe analysis of these particles 

has shown t hem to be rich in sulfur; K. Bigg of CSIRO, Australia, has demonstrated 

that they are made up of a mixture of ammonium sulfate and sulfuric acid. 

Thus Arctic haze seems to be created in large measure by the combination of 

high relative humidity in the Arctic atmosphere (primarily near 1 or 2 km), high 

concentrations of sulfate (from midlatitude S02), and long residence times. 

99 
5.6 Nature of the Aerosol at Barrow 

E. K. Bigg 

CSIRO 

Sydney, Australia 

A project to collect particles at baseline air pollution monitoring stations 

was begun in 1975. Size distributions, chemical nature, and physical characteristics of the particles were recorded with an electron microscope. Thus aerosol 

properties at each site were documented as a reference against which to measure 

future changes and to aid interpretations of other measurements, such as backscattered light and turbidity. 

Bigg (1977) published a detailed description of the aerosol at MLO based on 

observations made continuously during 6 weeks in mid-1975. After another 6-wk 

sampling in 1976, the collectors were transferred to Barrow, Alaska, and used 

for 6 weeks between December 1976 and March 1977. Further co ntinuous samples 

were taken from March 21, 1978, to May 25, 1978 . Continuous collections have 

also been made at the Australian baseline station at Cape Grim, Tasmania, since 

Apri l 1976, and a new sampler was installed at spa in January 1979. In Mauna 

Loa and Barrow collections and during the first 2 years at Cape Grim, aerosols 

were impacted directly onto electron microscope grids for a few minutes every 

hour, the grids moving very slowly (one per 7 h) beneath the nozz le. Grids on a 

second turntable formed the collecting surface of an elecLrostatic precipitator 

to capture parLicle s down to about O.OI-~m diameter. At South Pole and Cape 

Grim after mid-1978 reduced-pressure impactors were used to obtain the small 

particles. 

Rahn et al. (1977) called attention to the Arctic haze, a variable but high 

turbidity observed in the supposedly clear Arctic regions, particularly in 

spring. They deduced that continental dusts from Asia were responsible for the 

haze. The aerosol that we collected in 1976-77 showed unequivocally that the 

dominant light-scattering particles were almost entirely sulfuric acid, although 

a fair proportion of lhem contailled solid electron-dense inclusions. Clay 

particle~ (rlat irreglilar plates partly transparent to electrons and stable to 

heat) \vf're prf'sent bilL. .ll\vays as a minor constituent. 

Figure 62 shows a typical group of particles collected on a carbon surface 

precoated with silicone 011 at 1700 h local time on December 15, 1976 . Droplet 

rings surrounding a central particle are typical of sulfuric acid. When collected 

on a calcium-fluoride-coated surface the sulfuric ac id reacts to form calcium 

sulfate, and any insoluble inclusions are revealed (see fig. 63) . 

The main conclusions are as follows: 

(I) Sulfuric acid was the dominant winter aerosol in 1976-77. 

(2) Winter size distributions in 1976-77 were relatively constant . 

(3) In spring 1978 the sulfuric acid particles contained a very variable 

and sometimes much greater proportion of ammonium sulfate than in winter . There 

were more large particles than in winter . 

(4) From 10% to 20% of the acid particles contained insoluble inclusions 

ra nging from spheres through irregular but compact forms to highly irregular 

chains or aggregates of sma ll particles. 

(5) Clay particles uncoated with acid we re observed at irregular intervals, 

particularly during the spring of 1978. 

(6) The most common size of particles per unit logarithmic radius interval 

100 
"r·-J:. _." 

• ~/ 

.. I'~ .. ~ .. P .. l .. ' 

~ 

.' 

• - . (I'· ... ~.F.;: .4 .... \ 

.... ~ "' ..... "- . ., ~ . 

~ J~ ~ . r' 

~ 

, 

.,$ .~ 

•• 

Figure 62.--Particles collected on a 

ca rbon surfa ce at Barrow, Alaska, 

at 1700, Dec 15, 19 76. 

• Jt .. • .. • 

:. 7,:; \it ..... ,.ft." 

Figure 63.--Particles collected on a 

calcium fluoride surface at Barrow, 

Al aska, Jan 197 7. Sulfuric acid 

comp onent has reacted with the calci um fluoride. Even dark particles 

have an acid coating. 

was between 0.1 and 0.2 ~m, whic h is larger than at the other sites examined. 

(7) Vertical soundings of the aerosol were made in June from a light 

aircraft by using an impactor and Aitken counter. Particle concentrations were 

greatly depleted below the strong temperature inversion at about 300 m. 

These conclusions are not completely consistent with Rahn a nd Shaw ' s (1978) 

re-assessme nt of the origin of the Arctic ha ze . The fact that surface aerosol 

concen trations are so different from those at 300-m hi gher altitude suggests 

that vertical profiles of the aerosol at this station s hould form an essential 

part of monitoring. 

5 . 7 Ice Nucleus Measurements 

Takeshi Ohtake and Andrew Fountain 

University of Alaska 

Fairbanks, AL 99701 

To determine the source regions and concentrations o f ice nuclei in the 

Alaskan atmosphere, an ice nucleus observing program was set up by the Geophysical 

I nstitute, University of Alaska. For the 11 months of t he project t hree sites 

were set up for data co llection : Barr ow (GMCC), Fairbanks, and Homer. Two 

temporary sit es , one aboard a trans-Pacific ship and the other on Attu Island in 

the Aleutian Chain, were a ls o used. At each sit e two filters, each samp ling 

different vo lumes, were exposed simultaneously. 

101 
oro estimate better any effect that conde nsa tion nuclei may have on the 

filter method of ice nuclei collection, the Barrow GMCC station also measured 

the condensation concentration during the fi lte ring period with a G.E. condensation nucleus counter. At the Fairbanks site i mpa c t o r samples were taken for 

later analysis in the combined X-ray energy spec trometer and scanning e l ectron 

microscope. Tllis instumenlatioll yields a qualitative estimate of chemical 

composition of tile ice nuclei. 

Bec~use of the close network of sites and their a lmost north-south alignment 

it is hoped tllat the correlation of s t ation data and air flow tra jectory will be 

more accurate and lherefore more comparable than the large , widely spaced networks 

previously used in lile north Pacific . The three sites also r ep resent the three 

climatic zones of Alaska: the north slope, interior , and southern coast. When 

lhese stations are ~ll sllbject to the same general air fl ow , the local climatic 

charilcteristics ShOllld appear, and it ]nay be possible to estimate better the 

local effects of the ice nuclei concentration. 

5.8 ~lulLi"avelengt h Tucbidity at ~Iau a Loa Observatory 

Glenn E. Shaw 

University of Alas ka 

Fairbanks, AK 99701 

Mulliwavelrngtll sunphotometers were calib rated at Mauna Loa in December 

1978 and in Harch 1Y79 after ficld ~ork "ith the instruments in Antarctica. The 

two calit)1"~ti0ns, sP~laratpd in timp by 4 mon th s, gave ca l ibration cons tants that 

agreed from 0.3% to 1.0%, with lhe largest variations occurring at the shorter 

,,"velengths (the "dv,>Length range samp led was 400 < A < 1000 nm) . The close 

agrecmeIlt ill th!' calibralion constants demonstrates the excellent s ky conditions 

<It the ohspr'lt r))-V: "It more tllrhid stations one normally finds fluctuations of 

10% to 20~ .n tile Langley plot calibrations (Shaw et al., 1973) resulting from 

diurrlal challges jn aerosol concentrations" Aeroso l conditions at Mauna Loa are 

I ,t noticedl If' lInL.li nldday. \dlPn aerosols are advected upslope to the observatory. 

AI ('Ul' del .1 ....... t hOI Il the morning hours_ 

'"lip lila II I II 1Of'1 i fP]I]!'llts indicale that the comb ined upper tropospheric 

anrl str .. tos i1f'r i ( 1(-' '0501 opti cal thickness was smaller than it was in spring 

1976 and in 1977 Tllcs. observations indicate that the stratosphere has rec)ver ~ ()'(m v0IClQ]( DC "ttlrllations created by the eruptions of Agung and Fuego. 

Optical attellll<-1l]( II ell )00 nm v.'3velength \vas 1.5% to 2.0% when the Sun was nea r 

the zenith. 

The same vallIPs of optical extinction (to the limits of uncertainty) were 

found al South Pole Station and at HLO in December 1978 and January 19 79, but 

slightly smaller v~ltles! by about 10%, ",'ere measured from the s ummit of ~lt . 

Ereblls, Antarctica, in January 1979. Some measurements of turbidity (aerosol 

)ptical depth) at different stalion altitudes are shown in fi g. 64. 

Besides the optical calibrations , we also co llecte d samples o f aerosol at 

Hauna Loa with a Bigg impactor. The analysis of X-ray spectroscopy is not yet 

complete, but initial inspections indica t e that a large proportion of s ulfur 

exists in the samples taken. It is not certain if the samples were contaminated 

by the volcano's effluent. 

102 
lI 

o 

w 

I 

MLO 

3 

f--J\\--..., South Pole 

Table Mtn 

·Y.2! !!.!i~ __ " Lowell Obs 

2 " KIt! Pk 

• Averages 1905 - 1<)48 

'" AvelOges ofter \955 

~ Range of reported Va,ues 

U I USA ~ __ ~ ________ r-~~pp~s~a~a~_._,, ~~ __ ~~~ __ ~ ______ ~~~,~.~ _____ _ 

00 005 010 

T 500 

015 o 2(J 

Figure 64.--Plots of turbidity at mountain observatories (T at 500 om) as a 

fun ction of altitude, showing increase s since 1955. D,lt,jOat"e from Volz 

(1978) and Flowers et al. (1969). 

5.9 Pyrheliometer Measurements at Mauna Loa Observatory 

G. D. Robins on 

Center for the Environment and Han 

Hartford, CT 06120 

We have continued work on the record of the glass filler channels of the 

broad-band pyrheliometer. The redundancy in the observations, provided by tilP 

overlap of the c hanne l s , a l lows an estimation of the systenlatic errors int rodllced 

by thermopile calibration errors and incorrect assumptions cOllrerlling the filter 

cut-off wavelengths. The method requires extrapolation to zero air mass of the 

difference between the measured signal and that computed for a standard particlefree atmosphere. The assumptions concerning the extraterrestrial solar spectral 

irradiance are given in the 1977 Summary Report. The standard atmosphere 

103 
attenuation was recomputed, using the new Fr~hlich-Shaw (1978) approximation for 

Rayleigh scattering and the Labs-Ne ckel spectrum in 10-run bands. Figure 65 

shows the results of two data sets after error analysis. The method does not 

provide a unique analysis, and in fig. 65 all adjustments have been made by 

changing the relative sensitivities of the thermopiles, with no change in the 

assumed cut-off wavelengths. The overall average thermopile sensitivity, of 

course, is not changed to preserve the relation to the accepted solar constant 

through reference to a common substandard. 

Figure 65 shows measurements on the 2 days in August 1975 discussed in the 

1977 Summary Report and the average of 7 days in Narch and April 1974. Note 

that the intercept on the zero air mass axis is less than 1 W m- 2 in all cases, 

indicating that the observations are compatible with the assumptions concerning 

solar spectral irradiance within about one-quarter percent. The slopes of the 

lines imply an attenuation tm in excess of that assumed in computation where t 

(per air ma ss) is: 

~lar/Apr 1974 

Aug 23, 1975 

Aug 24, 1975 

GG22/0Gl Channel 

0.010 

0.022 

0.026 

OGl/RG8 Channel 

0.021 

0.012 

0.009 

The 1975 values are of the ma gnitude expected for attenuation by particles, but 

the high value of 0.021 for the OGl/RG8 channel in 1974 relative to that for 

GG22/0Gl is difficult to explain, particularly as the average of 7 days, although 

it would be reduced to 0.005 if the assumed ozone column were increased from 

0.275-cm STP to 0.325-cm STP (the t for GG22/0Gl would be 0.008 for this ozone 

column). All adjusted measurements are compatible "ith the assumptions within 

1% to 2% o[ Lh e irradiance in the differential pass bands, which is better than 

0.5% of the measured irradiance of the RG8 channel and l ess than 0.25% of the 

solar consta nt. 

15 

E 10 

S 

'" u 

c 

'" 5 -c 

~ 

"0 

~ 0 "----'-------'------' ~ 

m '" 10 

~ 

"0 

9 5 

;; 

o 

o bo"""------~-:-c-! OG1 ! RG8 

o 2 

Air Mass 

GG22! OG1 

• 

OG1 ! RG8 

o 2 

Air Mass 

104 

Figure 65 . --Extrapolation to zero air 

mass of the difference between computed mea s ur ed irradiance in spectral bands defined by GG22, OGl, 

and RG8 filters (m.o multi channe l 

pyrheliometer). + - Aug 23, 1975; 

o - Aug 24, 1975; • - Nar-Apr 1974. 
Because of solar tracking and a tmospheric variability during the hour or 

mor e with relatively high Sun needed in the metilod, very few days were found on 

which it cou ld be applied. The multichannel instrument has now been replaced by 

a hand-poi nted filter whee l, but preliminary analysis indicated that the optimum 

performance of the mult ic hannel pyrheliometer has not yet been matched. 

5.10 Ultraviolet Erythema Global Measuring Network 1978 

Daniel Berger 

Temple University 

Philadelphia, PA 19140 

The s unburn ultraviolet meter network has operated for more than 5 years . 

The col le cted data represent the dose of s unbu r n effective ultraviolet radiation 

rece ived on a flat detector in each half hour. Twenty-five stations are presently 

providing i nterrelatable data (see table 27). A computer compatible oULput has 

been developed and installed at th ree stations. Collected data are disseminaLed 

on request by NOAA, 8060 13th Street, Silver Spring, MD 20910. 

Table 27 .--Stations in s unbu r n ultraviolet meter network 

Sunburn ultraviolet sta tions 

Bismarck, N. Dak. 

Tallahassee, Fla. 

Oakland, Calif. 

Fort Worth, Tex. 

Minneapol is, Minn. 

Des Moine s , Iowa 

Albuquerque, N. Mex. 

El Paso, Tex . 

Mauna 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 

Aspendale (Melbourne), Australia 

Brisbane, Australia 

Davos, Switzerland 

Hamburg, Germany 

Panama 

Point Barrow , Alaska 

Ro c kville, ~Id. 

105 

Period in continuous operation 

Oct 1973-present 

Sep 1973-present 

Oct 1973 - present 

Sep 1973-present 

Oct 1973-present 

Oct 1973-presenL 

Sep 1973-present 

Sep 1973-present 

Dec 1973-present 

Sep 1974-present 

Nov 1974-presenL 

Sep 1977-present 

Sep 1977 - presenL 

Oct 1977-present 

Sep 1977-present 

Oct 1977-presenL 

Jun 1975-present 

May 1975-present 

Jun 1975-Sep 1976 

Jun 1974-present 

~Iay 1974-presenL 

Oct 1974- present 

Feb 1976-present 

Nov 1978-present 

Oct 1978-present 

Sep 1978-present 
The network is continuing to expand. Stations in San Diego, Calif., and in 

New Zealand are being added. Requests from other sites are being considered. 

The data have been related to biological responses and to meteorological 

models. A bibliography of pertinent articles can be supplied on request. A 

compilation and analysis of data collected in 1974, entitled "Measurements of 

ultraviolet radiation in the United States and comparisons with skin cancer 

data," was published by the Department of Health, Education, and Welfare. A 

multiyear analysis of data is being completed by the same organization. 

5.11 Satellite-Based Estimates of Solar Radiation 

For the GATE Study Area 

John E. Hay 

CIRES, NOAA 

Boulder, CO 80303 

A study was made to map at appropriate time (6 h) and space (6 mil scales 

the distribution of shortwave radiation incident at the sea surface for the GATE 

B scale study area (7 0 -10 0 Ni 22 0 -25 0 14) for the study period June 28 to September 

19, 1974. The data are required for such studies as investigations of the 

energy budget of the tropical atmosphere and the interactions between the atmosphere and the underlying ocean surface. 

The only source of data with the required resolution in time and space is 

the Synchronous tleteorological Satellite (StlSl) located above the Equator and at 

45 0 IV during GATE. This source provided hourly values of visible (0.55- to 

0.75-~m) and infrared (10.5- to 12.6-~m) spectral data at 2-mi and 4-mi resolutions, respectively. The research project attempted to derive a relation between 

the satellite observations and the solar radiation at the surface, the latter 

data coming from measurements by one Canadian and four U.S. ships. 

A parameterization relating satellite-observed visible reflectivity and 

atmospheric shortwave transmissivity has been developed using the radiation data 

from the four U.S. ships. Examples are shown as figs. 66 and 67. Verification of 

the technique by using the Canadian radiation data shows that hourly shortwave 

radiation can be estimated to ±22% with a marked improvement for daily time 

periods to ±8%. Systematic errors over longer time periods (typically 20 days) 

reduce to less than 2%. These results compare very favorably to those of Davies 

and Uboegbulem (1979), who used a semi-empirical radiative transfer model and 

conventionally observed cloud and upper air data to calculate shortwave radiation. 

They found that even for 5-day running means the differences were still as large 

as 10% to 15~~, this relatively poor performance being attributed to problems in 

characterizing the cloud (particularly cumulonimbus) conditions. 

The satellite data base and the parameterization are currently being used 

to map the distribution of solar radiation for the GATE B scale array and to 

investigate the impact of areal averaging and navigation errors on the accuracy 

of the calculated radiation values. 

106 
1.0 r ···· ..... - - ····,·········r··· ····,·········,·········r········,·········,······ .. ·,·'- --, , Researcher. Phase 1. Hourly .[ 

3 KM Resolulion 1 -- y '" 0.79 - .076X .. ~ 0 0 0 

~ 0.8",.8i1~0 O~ R '" 0.85 SEE"" 0.11 

E 

"' c 

~ 

• - - - y '" 0.788 - 0.7 11 X 

•• 

• ~ 0.6 

Q; 

'" c. 

"' o 

E 

;;: 0.4 • • • 

g 

.!:! 

'" • E 

<; 0.2 

z • • 

• • • 

o '-..... ~. I ••• •••• ..t .~ •• .J.....................L.... ~·_~~ __ . I • • ••••••• I ........ ..t •.••• ~ 

o 0.2 0.4 0.6 0.8 1.0 

Normalized Satell ite Reflectivity 

Figure 66.--Relationship betwee n normalized hourly values of sate llite 

re flectivity and atmospheric transmissivity for Researcher during 

Pha s e 1 (Jun 28 to Jul 16, 1974) 

of GATE . Solid line is best fit 

for plotted data points . Dashed 

line is best fit for all ship/all 

pha s e data. 

1.0 

~ 

~ 0.8 

"' E 

'" c 

'" ,= 0.6 

" Q; 

'" c. 

'" 0 

§ 0.4 

« 

"0 

. " !:! 

;;; 

§ 0.2 0 

z 

0 ... 0 

• ~ • • '% 

• 

• • , , , . 

, 

Researcher. Phase 3. Daily 

3 KM Resolution 

--V '" 0.8 1 - O.77X 

R '" 0.96 SEE", 0.04 

- - - y '" 0.81 - 0.79X 

, 

"'", 0 , , 

. , 

',~ . 

'" 

' . 

• 

0.2 

~ __ ~~~~~ • • ..;J 

0.4 0.6 0.8 f.O 

Normalized Satellite Reflectivity 

Figure 67.--As for fig. 66, but for 

daily values for Researcher during 

Phase 3 (Aug 30 to Sep 19, 1974). 

5.12 Solar Radiation Fluxes at the Surface 

for t he Continent of Africa 

J e rome K. Nimira 

CIRES, 

Boulder, CO 

NOAA 

80303 

Monthly climatological solar radiation fluxes at the surfa ce for the continent of Africa between latitude 3D· N and 3D· S were estimate d by using Sadler's 

(1968) satellite-derived cloud data and other relevant climatol ogi cal parame t e rs . 

Two basic approache s were employed in the estimation of solar radiation . On e 

me thod was a semi-empirical tran sfer method and the other involved the linear 

re gre ssion me thod that uses c loud data and observed solar radiation. In the 

latter) the regression equation was developed for conditions over Swan Island. 

If this technique is va lid for conditions over Africa, differe nc es in the optically active atmospheric constituents over the island and any l ocation over the 

continent had t o be accounted for. 

The study data were climato logical: Janua r y , April, July , and October 

monthly mean va lue s of prec ipitable water, carbon dioxide, sunshine hours, total 

107 
ozone amount, and mean annual s urfa ce a lbe do. The sa t ellite-deri ved c l oud data 

were mean values f or each month . The spatial data point resolution was 2.5 0 

latitude by 2.5 0 longitude. 

The performance of the mode ls wa s judge d by comp aring estima t ed so l ar 

fluxes to observed values at 10 stations chosen from various climati c regimes 

over Africa . The results show that es tima ted and observed solar r adia tion 

f luxes on long monthly bases disag ree to within l ess than ±20%. The semi transfer 

method is better than the regression me thod because the percentage deviation of 

e stimates from observed mean monthly g l obal so l ar radiation for the 10 stations 

is ge nera lly less than ±ls% . 

Figure 68 shows typical monthly deviation from annual mea n f or observed and 

estimat ed solar radiation and table 28 gives the other sta tistics. 

In summary, t he r es ults s how that by using mea n monthly sa t e llite -derived 

c loud data and other re l eva nt c limato l ogica l parameters, a good simulatation for 

t he c lima t ol ogy of so l ar radiation fluxes for Afri ca ca n be obtained. This 

technique is useful for many parts of Africa where solar radiation observations 

are nonexistent or just beginni ng. 

30 

'" 10 ~ 

c 

c 

<t 

E 

Port Sudan 

,g 0~--/~'----------------- ~1--~ 

c ® <1'0:1 \ 

o I '" 

~ I \ 

~- J81 \ 

i -J

1

!" ~\ , \ '<1, 

1, J~-F~-M~~A--~M--~J--~J~-A~-S~-O~~N~O " " " "I 

Pretoria 

x 

x x 

I I I I I I I I I I 

J F M A M J J A SO N D 

Figure 68 . --~lonthly deviation of estimat ed global sol ar radiation f r om annual 

mean C%). 6 - obs erved, X - regression, 0 - semi transfer wi th c loud only, 

and 0 - semitransfer with cloud and s uns hine hour s. 

108 
'0 

N 

, 

L 

u 30 

(J) 

w 

H 

'" 20 0 

.J 

< 

U 

10 

' 0 

N 

, 

L 30 U 

(J) 

w 

<r 20 0 

-1 

« 

u 10 

Table 28.--Characteristics of observed ,nd esti.mated solar radiation 

Standard error 

Station estimate'~ Standard deviation·.': Variabilit:{'" 

R ST-C ST-CS R ST-C ST-CS Obs. R ST-C ST-CS Obs. 

Dakar 33 25 1. 20 26 22 30 .0' .1 2 .0' .1 2 

Accra 26 16 20 l' 20 15 24 .0' .10 .07 .12 

Kinshasa 33 3' 20 15 12 20 23 .08 .06 .11 .13 

Dundo 20 21 6 14 20 17 11 .07 .10 .08 .06 

Port Sudan 23 17 l' 35 33 20 46 . 14 .1 3 .08 . l' 

Pretoria 20 16 29 46 41 38 41 .22 .19 .18 .18 

Gulu 25 15 20 21 9 15 15 .09 .04 .07 .07 

Tabora 21 23 14 12 7 11 10 .05 .03 .05 .04 

Nairobi 29 25 16 13 24 18 39 .06 .11 .08 .17 

Lumbo 34 24 24 27 28 32 34 .13 .1 3 . 14 .1 5 

*R = regression method; ST-C = radiative transfer method. clouds only; ST-CS radiative transfer 

method. clouds ,nd sunshine. 

5.13 Monitoring the Spectral Quality of Solar Radiation 

B. Goldberg 

Smithsonian Institution 

Ro ckville, MD 20852 

In 1978 data collected in 1976 and 1977 with Eppley pre cision pyranometers 

were analyzed and published (Klein and Goldberg, 1978a) . From this analysiS an 

apparent, temporary drop in UV radiation was found in Panama and Rockville, ~Id., 

but not in Barrow (fig. 69). The cause of this phenomenon is not yet known. 

r 

j : 

; : , ;! 

i; 

, 

j < ! , 

if 

1973 

1973 

BARROV DAILY UV INSOLATION 

, 

I 

\ 

" 1974 

; 

I 

i : 

1875 

YEAR 

" 

!! 

.f 

, , 

~, 

\~ \ 

\ 

\. 

1976 

PANAMA DAILY UV INSOLATIoN 

1974 1975 

YEAR 

1878 

'. ': :i , I ~ 

1977 ~ 

1977 

ROCKVILLE DAILY UV INSOLATION 

'0 

N 

, 

L 

u 30 

(J) 

W 

H 

'" 20 0 

.J 

« 

u 10 

Figure 69.--Running 7-day averages of 

total UV radiation (400 om and below) 

for Barrow, Alaska (70 0 N), Rockville, 

Md. (39 0 N), and Balboa, Panama 

(9 0 N). 

109 
, 

E 

c 

" , 

" 

h 

2' \ LANGLEY, VA 

JULY 7.1978 

20 I 

,. I 

" 

• 

• ,. 20 

HOURS 

3 

, 

E 

c 

" 2 

, 

" 

h 

• 

LANGLEY , VA 

JUL Y 7, 1978 

.3 00 ." 

295 ... 

" HOURS 

05 "PI 

, . 

Figure 70 . --Integrated values of UVB in 5-nm bands centered at given wave -

lengths. Values were obtained fr om 1-min integrations by using a filterwheel radiomete r develope d by Smithsonian Radiation Biology Laboratory. 

The major area of work by the Radiation Biology Laboratory in 1978 was in 

UVB (erythemal UV) area of the so lar spectrum. Klein and Goldberg (1978b) 

report on mu ch of this work. A new inst rume nt, ca ll ed an integrating, scanning 

radiometer, was put into the field and comp ared with an older sampling unit . A 

very good correlation was fou nd between the two units . Figures 70 and 71 s how 

the good agreement between the two units on a clear day. A des cription of the 

new instrument i s being prepared for publication. 

The two sites where the two units were used are approximately 150 air mil es 

apart. The Langley site shows two "glitches " on the 305 -nm and 300- nm curves. 

These would normally be removed in pro cessing, but none of these data has been 

filtered. Each band is nominally 5 run wide. 

A s impl e model was constructed to allow computation of spectral irradiances 

in 100-run bands (Klein and Goldberg, 1978b). 

, 

E 

c 

N 

, 

" 

> 

0. ' 

0.3 

0.2 

o. , 

• 

ROCKVILLE. MO 

JULY 7. 1978 

" HOURS 

, 

E 

c 

" '" 

~ 

" 20 

006 ROCKVILLE, MO 

JULY 7 . 1978 

0.05 

0.04 3 0S ... 

0.03 r 0,02 

0.01 3 00 ", 

295 ~" 

• " ,. HOURS 

Figure 71.--Values of UVB obtained by a sampling unit on a fai rly clear day in 

5-nm bands centered at given wave l e ngths. Each point on the curve is an 

instantaneous value. 

l l O 

20 

20 
5.14 Nuclear Fallout and High-Volume Aerosol Collections 

Herbert W. Feely 

Environmental Heasurements Laboratory 

U.S. Department of Energy, New York, NY 10014 

Precipitation samples, which are analyzed for 90Sr fallout from atmospheric 

tests of nuclear weapons, are collected in plastic buckets at the Mauna Loa and 

Samoa Observatories on a monthly basis. They are currently combined into quarterly 

composites and are analyzed together with samples from about 70 stations in other 

parts of the world. An article by Feely et al. (1978) includes an interpretation 

of recent results, 

High-volume filter samplers, which sample air at about 1 m3 min-I, are 

operated for EML at all four GMCC observatories. These are part of a network of 

about 20 samplers operated for nIL, mainly in the Western Hemisphere. ~Ionthly 

composites of t he filter samples are analyzed routinely by gamma spectrometry 

for 7Be, 95Zr, 137Cs, and "'Ce. Until mid-1976 they were also routinely analyzed 

radiochemically for 2 10Pb, 90Sr, and 2391240pu. Results are reported quarterly. 

Table 29 swnmarizes quarterly mean concentrations of the various radionuclides 

measured in surface air filters for 1977 and 1978 . The cosmic-ray product, 7Be, 

is us ually high in concentration at the ~Iauna Loa Observatory throughout the 

year. This station appears to represent better the air of the upper troposphere 

than does the EML continental station at Chacaltaya, Bolivia, even though the 

elevation of t he latter (5220 m) is higher . Concentrations of 7Be at the South 

Pole Observatory typically show a summer maximum and winter minimum. Evidently, 

air from the high troposphere carrying 7Be takes longer to reach the surface 

layer during winter than it does during summer. This argues against a conclusion, 

based on observations of the seasonal variations in concentrations of surface 

level ozone at the South Pole, that attributes high wintertime ozone concentrations to rapid movement of air to the surface from the polar stratosphere or 

upper troposphere. 

The artificial radionuclides from nuclear weapons tests, which are currently 

measured in the filters, are the fission products 95Zr, 13 7 Cs, and 144Ce. At 

Hauna Loa Observa t ory high concentrations of 95Z r were found throughout 1977, 

and high concentrations of 137Cs and "'Ce persisted through the first half of 

1978 as a result of fallout from the November 17, 1976, Chinese nuclear test 

which had a yield of 4 megatons. Lower concentrations of these radionuclides 

were found at Barrow Observatory during this period, and negligible amounts of 

the radioactive debris from this Chinese test reached the stations in the Southern 

Hemisphere. Rather high concentrations of fresh fission products were sampled 

at Hauna Loa Observatory during September 1977 immediately following the Chinese 

low-yield nuclear test of September 17, 1977. Concentrations fell back to their 

earlier levels quickly, however, as this fresh debris was diluted by mixing 

within the troposphere. 

III 
Table 29.--Quarte r ly mean concentrations of ra di onuc lide s in surface ai r 

filter samples collected at GMCC observatories, 19 77 to 1978 

19 77 gua rte rs 1978 guarters 

2 3 4 2 3 

'Be efCi m- 3 ) 

BRW 

flLO 

SNO 

SPO 

95Z r etCi 

BRW 

NLO 

SflO 

SPO 

137C5 etCi 

BRW 

flLO 

SNO 

SPO 

14<1 Ce etCi 

BRW 

flLO 

SNO 

SPO 

88 54 34 62 66 56 

241 147 203 194 197 

57 78 99 104 83 

184 138 122 125 118 141 

m- 3 ) 

1.2 6.2 8 . 7 5 . 3 1. 7 1.7 

39. 40. 869 . 21. 1.7 1.4 

<0 . 5 <0 . 5 0 . 7 <0 . 5 <0 . 5 

<0.5 <0 . 5 <0 . 5 0.8 <0 . 5 <0 . 5 

m- 3 ) 

0 . 3 0 . 5 0 .6 1. 2 1. 7 2 . I 

1.4 2.3 7 . 2 2 . 3 3 .9 4.7 

0.1 0.1 0.1 0.3 <0 .1 

0.2 <0. I 0 .1 0.2 O. I 0.2 

m- 3 ) 

0.5 5 . 6 6.3 11.9 13.6 13.7 

18.6 34.2 154. 26 . 7 32 .4 34 .0 

<0.5 <0.5 1.0 0. 8 <0 . 5 

<0 .5 <0 . 5 <0 . 5 <0 . 5 <0 . 5 <0 . 5 

5.15 fleasurement of S02 and TSP at flau na Loa Observa t ory 

Richard Sasaki, Navis Kadooka, and Wilfred Ching 

Department of Health, State of Hawaii 

Honolulu, HI 96801 

26 

149 

92 

114 

<0 . 5 

<0 . 5 

<0.5 

<0 . 5 

0.5 

1.2 

0.1 

0.1 

3.8 

7 . 2 

0.5 

<0 .5 

4 

48 

175 

61 

192 

<0 . 5 

<0 . 5 

<0 . 5 

<0.5 

0.4 

0.6 

O. I 

0.2 

1. 7 

2 . 7 

<0 . 5 

<0 . 5 

A cooperative program with NOAA at the faun a Loa Observa t ory was initiated 

by EPA to measure sulfur dioxide and tota l suspended particulates. In 1976 when 

the NASN program was closed by EPA, an agreement was reached to continue monitoring these parameters because of the interes t to NOAA and the Air Program of the 

State of Ha\o/aii. 

A major reason to ob tain data from Mauna Loa Obs erva tory was to determine 

if a clear background for total suspended par ti culates existed within the State 

112 
of Hawaii to use as a standard against the continental SLAl'IS and NAl'lS site. The 

background level for total suspended particulates at Mauna Loa wi ll be computed 

when valid data are obtained for three years. ~lonitoring for total suspended 

particulates will be continued for an indefinite period to determine any 10ngterm trend . 

Measurement of 802 of MLO will determine two parameters: the concentration 

of S02 at that altitude and the increase of 502 due to volcanic activity. Final 

computation and assessment of these parameters will be accomplished early this 

fall. 

5.16 Precipitation Chemistry at Samoa and Mauna Loa 

Donald C. Bogen and Stuart J. Nagourney 

Environmental Measurements Labora tory 

U.S. Department of Energy, New York, NY 10014 

Monthly samples of wet, dry, and total deposition are collected at SMO and 

MLO. The samples are sent to the Environmental ~leasurements Laboratory for 

physical and chemical measurements. 

Table 30.--Chemical analyses of total, we t, and dry deposition at Ameri can Samoa, 

April 1977 through Narch 1978 

Total collector Wet collector Dry co llector 

Nean Range Mean Range Nean Range 

Volume (£) 6 . 30 0-12 . 14 8.67 1.64-14 . 00 

pH 6. 21 5 .75-6.70 6.00 5.55-6.51 

Conductivity 

(J..lS em-I) 

48.1 2 1-295 26.6 11.8-67.7 

C1 108 78 - 208 45 25-85 59 20-99 

(mg rno - I) 

504 -: 

(rng rno I) 

18 10.7-32 7.3 3.7-12.5 8.2 3.0-13.0 

N03- 1. 16 ND"-3.9 ND" ND'" 

(rng rno- I) 

0.23 ND*-1.4 7 

+ Na 63 43-125 27 16-48 32 11-49 

(rng rno- I) 

~lg +2 

(rng mo - I) 

7.9 5.1-15.9 3.3 2.0-6.4 4.2 1.4-6.4 

Ca+ 2 3.5 2.4-6.5 1.5 0.9-3.4 1.8 0.5- 2 .3 

(mg mo-I) 

K+ 3.2 1.8-7.0 1.1 0.7-2.0 1.5 0.6- 2 .5 

(rng mo-I) 

Total cations 

Total anions 1. 07 ± 0.09 1. 10 ± 0.08 1. 01 ± 0.06 

"ND - not detectable. 

113 
Volume (£) 

pH 

Conductivity 

(jJS cm -1) 

Table 31.--Chemical analyses of total, wet, and dry deposition at Nauna Loa, 

April 1976 through Narch 1978 

Total collector Wet collector Dry collector 

~Iean Range ~Iean Range tlean Range 

O. 18 0-2.56 I. 07 0-7 50 

5 .55 4.91-6.06 5 84 4.76-6 60 

10 6 5.6-23.4 6 4 2.8-15.5 

C1 O. II 0.01-0.38 0.10 Nll"-0.33 0.06 0.02 - 0 . 21 

(mg mo-I) 

SO, -, 0.81 0.04-5.48 0.64 0.01 - 4 .1 3 

(rng rna-I) 

0.26 0.03-0 80 

N03- 0.10 ND"-0.49 0.10 ND;·'-0.48 0.06 ~rn" .. -o. 40 

(mg rno-I) 

N. + 0.14 0.02-0.31 0.18 O,O} -1. 01 0.10 0.02-0.24 

(rng rno- I) 

~Ig +2 

(mg rno -I) 

0.04 ND'·'-0.14 0.03 NlJ":-O. 1 0 0.02 ND'·'-0.05 

Ca+ 2 0.09 ND'·'-0.24 0.10 ND·:: -O.46 0.07 ND"-0.22 

(rng rna-I) 

K+ 0.04 ND'·'-O.IO 0.04 ND";-0.37 0.02 ND·,"-0.17 

(mg rno 1 ) 

NO", - not detectable. 

The average monthly deposition value and range of results at Samoa for the 

period April 1977 to March 1978 are presented in table 30 . The concentration 

ratios of various anions and cations to sodium support the observation that sea 

s pray is the principal constituent of these deposition samples. 

The monthly mean deposition values and the range of results at Mauna Loa 

for the first 2 years of the program (April 1976 to March 1978) are presented 

in table 31. 

5.17 Precipitation Chemistry at Mauna Loa Observatory 

Richard J . Thompson and Ross Highsmith 

Environmental ~fonitoring and Support Laboratory 

U. S . Environmental Protection Agency 

Research Triangle Park, NC 27709 

During 1978, monthly wet precipitation samples were collected at the Mauna 

Loa Observatory by using a MISCO ~fodel 93 wet-only precipitation collector . 

Monthly samples were forwarded to the ACB/EMSL for physical/ chemi cal analysis . 

Results of analyses on representative samples collected at the Mauna Loa Observatory are presented in table 32 . All analyses were performed under accep table 

quality control. 

114 
Table 32 . - -Phys i cal/c hemi ca l analysis of rep resent at ive 1978 monthly we t prec ip i ta t ion s ample s at HLO 

Mont h Rain fa ll Vo lume Volume 

1978 MLO MLO ACB/EMSL pH Condo Acidi t y S04 N0 3 NH 4 CL CA K Mo No 

~ ( rai n gauge) (m& ) (m£) (pU ) S em- I) eq £ -1 ) (mgS04 £-1 ) (mgN0 3 £ -1 ) (mgNa £- 1) (mgCl £- 1) (mgCa £ -1 ) (mgK £- 1) (mgMg 1 -1 ) (mgNa £- 1) 

~ 

en f e b 0.00 0 0 

Apr 1. 15 0 0 

J un 1. 27 50 40 4 . 63 13.6 69.0 2 .03 . 9 .3 .36 . 25 <.13 .08 . 35 

Aug 2 50 50 0 

Oct 6 .25 225 2 15 4.70 7 . I 39 . 0 .61 . 1 <. I . 25 . 09 < .1 3 . 02 < . 11 

Dec .52 0 0 
5.18 Barrow Precipitation Data 

G. P. Claggett 

Soil Conservation Service 

U.S. Department of Agriculture 

Anchorage, AK 99504 

The Soil Conservation Service maintains the network of Wyoming shie ld ed 

precipitation gauges across the North Slope of Alaska which is funded by the U.S. 

Army Cold Regions Research and Engineering Laboratory . This network allows more 

accurate winter precip itation data to be collected in the Arctic, where snow 

precipitation in treeless regions has been notoriously difficult to measure. 

Before 1975, the National Weather Service obtained the only routine precipitation data on the North Slope at Barrow (since 1919) and Barter Island (since 

1950). The NWS standard 8-in rain gauge is used at these two coastal stations, 

sometimes wind shielded and sometimes not. An unshielded gauge is estimated to 

catch one-third of the precipitation. The addition of a sta ndard Alter wind 

s hield increases the catch to about two-thirds of the total. Use of the mor e 

elaborate wind s hie lding deve loped in Wyoming by Rechard and Lars e n in 1971 increases the catch to almost 100%. 

The network of Wyoming shielded precipitation gauges across Alaska's North 

Slope now numbers 11 sites (table 33). 

Table 33. --Sites of Wyoming shielded precipitation gauges 

Site Latitude Longitude Activated 

Barrow 7l 020'N 156°40'W 9/75 

Neade River 70029'N 157°25'W 12/75 

Barter Island 70 008'N 143°37'\; 9/75 

Prudhoe Bay 70 015'N 148°30'\; 9/76 

Jago River 69°42'N 143°36'\; 10/76 

Kavik River 69°30'N 147°00'W 10/76 

Toolik River 68°37'N 149°26' Iv 9/76 

Sagwon 69°26'N 148°34'W 11/76 

Chandalar Shelf 68°05'N 149°29'W 9/77 

Antigun Pass 68°08'N 149°35'\; 9/77 

Antigun Camp 68°JO'N 149°26'\; 6/78 

116 
5.19 Boron in the Marine Atmosphere : Distribution, Sources, and Fluxes 

Robert A. Duce 

University of Rhode Island 

Kingston, RI 02881 

As part of an URI program, air and rainwater samples \vere collected at the 

Samoa facility. Four air samples and six rain samples were collected by T. Fogg 

from August 18 to September 3, 1978 . Using impregnated filters to trap the 

gaseous 1 inorganic boron , we foun d t hat the concentrations were in t he range of 

)0 ng m 3 . Although we experienced some difficulties with this technique, it 

probably represents a lower limit on the boron concentrations . Particulate 

boron collected by Nuclepore filters was in the range around I ng m- 3 The rain 

samples have not yet been analyzed. 

5.20 Variab i l i t y of Atmospheric Carbon Dioxide Concentration 

G. I . Pearman 

CSIRO 

Hordialloc, Australia 

During a I- yr visit by G. Pearman to the GHCC laboratory in Boulder, two 

studies were made on aspe cts of t he annua l cycle of CO 2 , 

Usi ng t he 21-yr CO 2 r ecord ob t ained at HLO by C. D. Keeling, we attempted 

to ascertain whether t he amplitude of the annual cycle of concentration had 

changed over the period. The magnitude of the annual variation in CO 2 concentration 

appears to have increased by about 3% each year. Also the time of year when the 

concentration (due to respiratory activity) increases takes place a week or two 

earlie r now tha n 10 to 20 years ago. These observations i mply that significant 

changes have occ urred i n the activi ty of the Nor thern Hemisphere nont ropical 

biosphere. 

Variations in CO 2 concentration at auna Loa, which occur on time scales of 

10 to 20 days, were examined in some detail. Attempts were made to establish 

relationships between the 600-mb to 700-mb meteorology, as indicated by the Hilo 

radiosonde data, and these fluctuations in CO 2 concentrations. Although relationships were found , they did not explain the 10- to 20-day variability. It was 

concluded t hat a much more extensive ana l ysis of these events and the meteorology 

is required. 

In a second study, we used a 2- D computer model to simulate the global 

mixing of the atmosphere. By using iterative approximations the model established 

zonally averaged monthly surface carbon fluxes that were consistent with the 

observed annual variation of atmospheric CO 2 concentration at each GHCC and 

other CO 2 monitoring sta t ions. 

Attempts were made in a third study to examine the time and space variations 

of CO 2 concentration observed by aircraft sampling over the Australia - New Zealand 

region during the past 6 years. Although not complete, these studies have shown 

clearly the relations hip between CO 2 concentration variations and atmospheric 

stability that occurs at the subsidence inversion and tropopause levels in the 

atmosphere. 

117 
5.21 Carbon Monoxide Monitoring 

Wolfgang Sei l er 

Max -Planck Institute for Chemistry 

Nainz, Germany 

The air monitoring program of the Max- Planck Institute (MPI) in cooperation 

"ith NOAA is continuing to provide baseline measurements of the background CO 

mixing ratios in the upper a nd lower troposphere o f the Nort hern Hemisphere . 

The CO instrume nt "as insta lled at MLO in 19 73 a nd r ep l aced b y a n improved model 

in Marc h 1975. Seiler ( 1976) gives details of the instrumentation. The instrument monitors automatically and continuously and has a lower detection l imit of 

0.1 ppb. The response time is approximately 15 s , so s hort-t erm fluctuations of 

the CO mixing ratios can be observed . The ca l ibration control is performed 

automatically once every 3 h, using t"o CO ca l ibra tion sta nd ards of 60 a nd 120 

ppb, representative o f the range of the CO values found i n unpol luted North ern 

He misphere air . The CO instrume nt had been maintai ne d twice by ~lPI employees 

during the last 4 years and was found t o work satisfactor ily . During these 

occas i ons samples of the calibration standards were taken and compar ed in the 

laboratory "ith primary sta ndard s available in the MPI. 

The CO instrument has been opera ting continuously si nce 1975 excep t for 

severa l months during the second ha l f of 1977 whe n the instrument was moved into 

the main building, a nd subsequentl y the automati c ca libration failed. The CO 

data exhibit considerable variati on with a time period on the orde r of 4 to 5 

days, probably as a result of synop ti c scale meteorological influences. The 

variability is most prono unced during the late wi nter and s pring when the CO 

mixing ratios rise to co n cen trati o ns of 350 ppb. Short-term fluc tuations within 

time scales of seve ral minute s to one hour we re not observed, indicati ng that 

the CO r ecord at MLO i s no t influenced by l ocal an thropogenic and natural CO 

sources. Exceptions are automobiles passing the s tation and brush fires. 

There seems to exist a slight diurnal variation of the CO mixing ratios 

with maximum values during the early morning . This cycle is most probably 

ca us ed by the change of the local wi nd regimes with up slope and do"nslope "ind 

during daytime and nighttime, respectively. This diurnal variation would indicate 

somewhat higher CO mixing ra tios i n the lower troposphere below t he trade wind 

inversion re lative to the upper troposphere. 

Similar observations during measurements on the Tenerife I sland have been 

reported by t his author . Most interesting i s the seaso nal variation of the CO 

mixing ratios with minimum values (60 to 80 ppb) during sp ring. Several factors 

probably co ntribute to the observed variation of CO. First, enha nc ed concentra -

tions of t he hydroxyl radical (OH) during the summer co uld be res ponsible for 

the lower CO concentrations duri ng the late s umm er and autumn since r eac tion 

with OH is believed to be the primary loss mecha nism of CO in the a tmo sphere. 

Second, a seasonal va riation in the prevailing wind patterns, associated wi th 

the meridional mov ement of the ITCZ, could strongly influence the observed 

seas onal vari ation. 

The data base is not ye t sufficient to make any statements about a possible 

increase of t he CO mixing ratios in the Nor thern Hemisphere, resulting from 

anthropogenic activiti es. 

Its 
5.22 Stratospheric Nitrogen Dioxide Program 

W. Henderson and J. F. Noxon 

Aeronomy Laboratory, NOAA 

Boulder, CO 8030 3 

Automated instruments for measuring stratospheric N0 2 have been operating 

at Barrow, Nauna Loa, and Sa moa, and we are now compl eting analysis of the 4-yr 

period of data. The preliminary results confirm and extend the patterns established 

by brief spot checks with airborne equipment, but a l so provide useful co ntinuous 

monitoring which , particularly at Barrow, has been invaluable in studying transport in the stratosphere . The first phase of the program is compl ete, and we 

plan to terminate operations with the present equipment. We plan further measurements with redesigned instruments that will concentrate on the Arctic and 

include Barrow as a site. 

5.23 Total Ozone Measurements and TIROS-N 

J. Miller and W. Planet 

Nationa l Environmental Satellite Service, NOAA 

Washington, D.C. 20233 

The National Environmental Satellite Service has received total ozone 

records from 11 Dobson stations either operated directly by the GMCC or associated with it. The data records begin in November 19 78 and will continue 

through the operational lifetime of the TIROS-N series of operational environmental satellites. 

The infrared sounder (HIRS/s) on TIROS-N has spectral channels whose measured 

radiances can be correlated with the amount of total ozone . A multi-channel re -

gression scheme has been established whereby total ozone on a global scale can 

be deduced from the infrared measurements. To establish and upgrade the individual regression coefficients, coincident Dobson measurements and satellite 

observations are required . When a statistically significant data base of coincident measurements is obta ined, the regression coefficients will be generated 

and i mpl emented in the TIROS-N data processing system . Regression coefficients 

are latitudinally stratified and will be cha nged seasonally. 

5 . 24 Barrow Magnetic Observatory 

John B. Townshend 

U.S . Geological Survey 

Fairbanks, AL 99701 

The Barrow ~Jagnetic Observatory is located at the northern tip of Alaska 

about 500 mi (804 km) north of Fairbanks and about 200 mi (322 km) west of 

Prudhoe Bay, site of the North Slope oil f i elds. Its geographic coordinates are 

latitude 71.32° N and longitude 156.62° W. 

119 
The observatory, part of the U. S. Geological Survey's Branch of Electromagnetism and Geomagnetism, is used to produce accurate and comprehensive geomagnetic 

data. It was started in May 1949 as a manned station. In May 1975 a digital 

and analog fluxgate and proton magnetometer system was installed which includes 

the following instruments: fluxgate magnetometer (H, D, & Z), proton recording 

base magnetometer (F), data logger, tape transport (7 track/556 characters per 

in) , analog recorder (4 pen), battery system (4 ea. 6-V batteries 100 amp), 

battery charger, and d.c./a.c. inverter. The digital tape and analog recording 

paper are sufficient for the station to operate unattended for up to 7 weeks 

without major service. The station is operated by the U.S. Geological Survey 

College Observatory at Fairbanks, and one of the staff visits the station periodicall y (about every seven weeks) to change tapes, make absolute and scale value 

observa tions) and service equipment. NOAA Geophysical Monitoring for Climatic 

Change personnel at Barrow check the recording equipment weekly and advise the 

College Observatory staff of obvious problems. 

5.25 South Pole Riometer 

H. J. A. Chivers 

University of California-San Diego 

La Jolla, CA 92093 

Riometers have been operated continuously at South Pole throughout the year 

as part of a cooperative program between NOAA and the University of California 

at San Di ego. The ahsorption mpaSl1rempnts are rplatpri to the prpcipitation of 

charged parti c les into the ionosphere above the station. The South Pole combines 

the advantages of an excellent geomagnetic location for detecting particle 

precipitation and an unvarying cosmic radio noise background. Records of excellent quality have been gathered for 3 years and have led to an analysis of a 

class of absorption events ("spike" events), which precede a magnetic substorm. 

Using Riometers on two different frequencies (30 ~lliz and 51.4 ~lliz), we found 

that the spike events begin with precipitation of very energetic particles 

spatially confined t o about 10 km in width. Within a minute or so, the spectrum 

softens and the precipitation pattern becomes widespread across the antenna 

aperture. The results of this analysis lead to a more accurate description of 

the precipitation process from the magnetosphere, and are important in understanding the characteri s tics of communications difficulties at high latitudes. The 

work has been expa nded to include study of the interrelation between groundlevel cosmic ray events and radio-wave absorption . 

Origina l strip chart recordings from the South Pole riometers are archived 

in the National Geophysical and Solar-Terrestrial Data Center, NOAA, Boulder, 

Colo. 

120 
5.26 Antarctic Tritium 

Allen S . Mason and H. G~te Ostlund 

University of Miami 

tliami, FA 33149 

The University of Miami Tritium Laboratory, sponsored by the Division of 

Polar Programs, NSF, installed an atmospheric tritium sampler (fig . 72) in the 

CAF at the Amundsen-Scott South Pole station in late 1977. In late 1978, J . 

Bortniak of NOAA assumed operation from S. Barnard of SUNYA and is responsible 

for the sampler through the 1979 austral winter. 

Samples are taken of tritiated water vapor (HTO) by absorption and of 

tritium gas (HT) and tritiated hydrocarbons by selective oxidation and a bsorption. 

The sample traps are returned to Miami for extraction and analysis. The research 

objectives are elucidating the flux of HTO at the surface and determining the 

global backgrounds of HT and tritiated h ydrocarbons. The HTO is a tracer for 

ordinary water vapor and will be useful in study of continental water budget. 

The HT and hydrocarbons are products of ongoing nuclear activities, and Antarctica 

is an ideal location for measuring their global backgrounds. 

With the projected advent of fusion power, the world HT burden will probably 

increase greatly. These studies will provide a baseline for the estimation of 

the effects of such an increase. 

0 IIYDI:()(;IN 

• 

t 

• • 

<.""""., ." ... 

D ... 

e • 

!' , .. • 

" r ", • • 

... 

I-

• • , . , <9 • , 

\-

121 

Figure 72 . --Atmospheric HT / HTO/CH.T 

sampler. 
5.27 Atmospheric Electric Measurements 

at Nauna Loa Observatory 

William L. Boeck 

Niagara University 

Niagara University, NY 14109 

Donald E. Olson 

University of Minnesota 

Duluth, NN 558 12 

J. Doyne Sa rto r 

National Center for Atmospheric Research 

Boulder, CO 80303 

Since 1960 W. Cobb has made intensive observations of the atmospheric 

electrical parameters at MLO. The observations and his results have received 

renewed attention in connection with solar weather interactions. Cobb (1967) 

reported anomalously high electric fields and conductivities at Nauna Loa after 

maj or solar flare eruptions. Other observations at high altitude observatories 

in the Bavarian Alps and the Colorado Rockies tend to support those of Cobb but 

are subject to greater contamination from local anthropogenic sources and adverse 

weather. A major cloud and thunderstorm mechanism receives its start from the 

fair weather electric field and conductivity. Stronger fair weather (globally 

responsive) electric fields and conductivities such as those observed on Mauna 

Loa favor more rapid and more intense electrification of available c louds on a 

worldwide scale. To substantiate these suggestions a l onger period of intensive 

measurements is required . Since 1977 NLO personnel have helped us maintain 

chart recordings and inspect in s truments. To ensure continuous quality data we 

have made periodic visits to the observatory to service instruments. 

Reduction of raw data from strip chart records has continued. We have 

tried to update the components of the electric field mill without changing the 

calibration or function . Nodules have been constructed to simplify the repair 

procedures, reduce component cost, and increase reliability . 

The supe rposed epoch analysis me thod as used in solar/weather research has 

been analysed to i mprove the credibility of the results of this method. 

122 
6. INTERNATIONAL ACTIVITIES 

In January 19 78, K. J. Ha nson traveled to the South Pole to inspect and 

review the GNCC program there. On the return trip he also reviewed the G~ICC 

program a t Samoa and ~launa Loa. 

Under the U. S.A.-U . S.S .R. Agreement on Cooperation in the Field of Environmental Protection, Working Group VIII, J. Peterson traveled to Leningrad, Soviet 

Union, during August 1978. While there he consulted with Soviet scientists on 

their preparation for an urban-oriented aerosol experiment. They were operating 

two lidar systems as well as optical a nd pape r filter aerosol samplers. J. Peterson also brought a Volz sunphotometer to Leningrad for comparisons with a similar 

Soviet device and for urban-rural atmospheric transparency measurements. These 

sunphotometer measurements are described in section 4.8 . 

Also under the U.S.-U.S.S.R. bilateral agreement, V. A. Kovalev and S. A. 

Sokolenko visited the NOAA Air Resources Laboratory, Boulder, Colo., from Septemb er 10 t o October 8, 1978, to check the calibration of U.S.S.R. Dobson ozone 

spectrophotometer no. 108 and to modernize t he electroni cs of the instrument. 

U.S. collaborators in the instrument comparisons were W. D. Komhyr and R. D. 

Grass of GNCC. An initial comparison of U. S.S .R. instrument no. 108 with U. S . 

world reference standard Dobson instrument no. 83 on September 21, 1978, showed 

that the two instruments yielded AD wavelength direct sun total ozone data that 

agreed on the average to within 0 . 6% for observations made within the air mass 

observing range of 1.3 to 3.2 . A maximum difference of 1.0% in ozone data was 

observed within the air ma ss interval 1.5 to 2.0. Dobson ozone spectrophotometer 

no. 108 is used in t he U.S.S.R. for ca librating ~1-83 filter ozonometers that are 

routine l y employed for t otal ozone meas urements at the U.S.S.R. ozone station 

network. Modifications to instrument no. 108 included installation of modern 

solid-state electronic circuitry and minor optic adjustments. A final intercomparison of instrument nos. 108 and 83, on October 6, 1978, yielded excellent data, 

indicating average AD, CD, A, C and D wavelength ozone value differences for the 

two instruments of less than 0.2% within the air mass range of 1 . 15 to 3.2. 

During 1978 GNCC personnel continued to participate in the IVNO Global Ozone 

Nonitoring and Research Project to upgrade the quality of Dobson spectrophotome -

ters throughout the world. Instruments upgraded by use of modern electronic 

c ircuitry and calibrated by direct comparison with world standard Dobson instrument no. 83 maintained by GNCC were nos. 52, 93 and 98 located in ~Ianila, Philippines, Natal, Brazil, and t1exico Ci ty, tlexico, respectively . Ins trument no. 

93 has been loaned indefinitely to Brazil. Data from the station will be used 

for ground truth information to support a NASA rocket ozone sonde program. 

In December 1978, K. J. Hanson traveled to Riga, Latvia, to participate in 

the World fleteorological Organization/United Nations Environmental Program 

International Symposium on Integrated Nonitoring for Environmental Pollution . 

He presented a paper at the symposium entitled, "Comments on the Specification 

of Network Stations for Nonitoring the Variability of Atmospheric Trace Constituents Significant for Climate . 1I 

123 
7 . PUBLICATIONS AND PRESENTATIONS BY G~ICC STAFF 

Berri, G. J., and J. T. Peterson. Dependence of atmospheric turbidity at 

Raleigh, N.C. , on air mass trajectories. NOAA Tech. ~Ie o. ERL ARL-68, 

16 pp., Feb. 1978 . 

Bodhaine, B. A. The ~launa Loa four wavelength nephelometer: Instrument details 

and three years of observations. NOAA Tech. Rep. ERL 396 -ARL 5, 41 pp., 

Apr. 1978. 

Bodhaine, B. A. A possible effect of local volcanic activity a t Mauna Loa 

Observa tory. In Mauna Loa Observa toryna 20th Anniversary Report, J. M. 

Miller (ed.), 66-71, Sep. 1978. 

DeLuisi, J. J. Use of the Dobson spectrophotometer in a variable wavelength 

mode as an alternative to the Umkehr measurement for observing trends in 

the verticle distribution of ozone. Proc . WMO Symp. on Geophys. Aspects 

and Co nsequences of Changes in Composition of the Stratosphere, Toronto, 

Canada, June 26-30, 1978. 

DeLuisi, J . J., and J . Nimira . Preliminary comparison of satellite BUV and 

surface-based Umkehr observations of the vertical distribution of ozone in 

the upper stratosphere . J. Geophys. Res. 83(C1):379-384, Jan. 1978. 

Fegley, R. W. NOAA Air Resources Laboratories Stratospheric Lidar Project--

1976 Results . NOAA Tech . Rep . ERL 400-ARL 6, 13 pp., Sep. 1978. 

Fegley, R. W. , and C. H. Penney. An attempt to measure atmospheric ozone with 

ultraviolet lidar. NOAA Tech. Memo . ERL ARL-75 , 20 pp . , Dec. 1978 . 

Fegley, R. W., E. W. Barrett, and H. T. Ellis. 

Observatory. In ~launa Loa Observatoryna 

Hiller (ed.), 59-65, Sep. 1978. 

Lidar mea surements at Mauna Loa 

20th Anniversary Report, J. M. 

Hanson, K. J . Comments on the specification of network stations for monitoring 

the variability of atmospheric trace constituents significant for climate. 

Proc. ~1O/UNEP Inter. Symp . on Integrated ~lonit. for Environ. Pollut., 

Dec . 1978. 

Herbert, G. A., and B. C. Halter. Geophysical monitoring for climatic change at 

the South Pole, 1977. Antarct. J . U. S. 13(4) : 190-191, Oct. 1978. 

Hoyt , D. V. An explosive volcanic eruption in the Southern Hemisphere in 1928 . 

Nature 275(5681):630-632, Oct . 1978. 

Hoyt, D. V. Interannual cloud- cover variations in the contiguous United States. 

J. Appl. Meteorol. 17(3):354-357, Har. 1978 . 

Hoyt, D. V. A mod e l for the calculation of solar global insolation . Solar 

Energy 21:27-35, July 1978. 

Hoyt , D. V. Reply (to Court). lon. Weather Rev. 106(4):572-573, Apr. 1978. 

124 
Hoyt, D. V. Variations in the solar constant mea surements of the Smithsonian 

Astrophysical Observatory, 1923-1954. Third Conf. on Atmos. Rad., June 28-

30, 1978, Davis, Calif. Preprint, A.H.S., Boston, Hass ., 315-317, June 

1978. 

Hateer, C. L., D. F. Heath, and J. J . DeLuisi. Seasonal variation in the vertical 

distribution of ozone as observed with the Umkehr and BUV methods. Proc. 

~10 Symp. on Geophys. Aspects and Consequences of Changes in Composition of 

Stratosphere, Toronto, June 26-30, 1978. 

Hendonca, B. G., K. J. Hanson, and J. J. DeLuisi. Secular trends in clear sky 

transmissions at Mauna Loa Observatory--peturbations in stratospheric 

aerosols. Third Conf. on Atmos. Rad . , June 28-30, 1978, Davis, Calif. 

Preprint, A.H.S., Boston, Hass., 330-332, June 1978. 

Hendonca, B. G., K. J. Hanson, and J. J . DeLuisi. Volcanically related secular 

trends in atmospheric transmission at Mauna Loa Observatory, Hawaii. 

Science 202:513 - 515, Nov. 1978 . 

Hiller, J . ~l. The complexity of the wind patterns at Hauna Loa. In ~launa Loa 

Observatory--a 20th Anniversary Report, J. H. Hiller (ed.), 122-128, Sep. 

1978 . 

~liller, J. H. (ed.). Mauna Loa Observatory--a 20th Anniversary Report. NOAA/ARL, 

158 pp., Sep. 1978 . 

Hiller, J. H. , and J. F. S. Chin. Short-term disturbances in the carbon dioxide 

record at Hauna Loa Observatory. Geophys . Res. Lett. 5(8):669-671, Aug. 

1978 . 

Hiller, J. M., and A. M. Yoshinaga. Use of a standard raingage as a precipitation 

chemistry collector (comments on liThe effect of some meteorological parameters on the chemica l compo sition of precipitation at the University Field 

Station, Trinidad, West Indies") . J . Appl. leteorol. 17(11): 1747-1748, 

Nov. 1978. 

Hiller, J. M., J. N. Ga lloway, and G. E. Likens. Origin of air masses producing 

acid precipitation at Ithaca, New York: A preliminary report. Geophys. 

Res . Lett. 5(9):757-760, Sep. 1978. 

Peterson, J. T. (ed.). Geophysical Honitoring for Climatic Change, No.6, 

Summary Report 1977. NOAA/ARL, 145 pp., Dec. 1978. 

Peterson, J. T., and T. L. Stoffel. Urban-rural solar irradiance measurements 

at St. Louis. Third Conf. on Atmos. Rad., June 28-30, 1978, Davis, Calif. 

Preprint, A.H .S., Boston, Hass . , 319-321 , June 1978. 

Peterson, J. T., E. C. Flowers, and J. H. Rudisill III. Atmospheric turbidity 

across the Los Angeles Basin. J. Appl. Heteorol. 17(4):428-435, Apr. 1978. 

Peterson, J . T. , E. C. Flowers, and J. H. Rudisill III. Urban-rural solar 

radiation and atmospheric turbidity meas urements in the Los Angeles Basin. 

J. Appl. Meteorol. 17(11):1595-1609, Nov. 1978. 

125 
8. REFERENCES 

Angell, J. K. , and J. Korshover, 1978. Global ozone variations: An update into 

1976. Mon. Weather Rev. 106:725-737 . 

Bigg, E. K., 1977. Some properties of the aerosol a t Mauna Loa Observatory. 

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Bodhaine. B., 1979. Aerosol monitoring at Barro\o,', Nauna Loa, American Samoa, 

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Atmospheri c concentration 

Science 183 :198-200. 
9. G~ICC STAFF 

Directorls Office 

*Kirby J. Han son, Director 

*Bernard G. Mendonca, Depu ty Direc tor 

Helen C. Cook, Secretary 

Dale A. Gillette, CIRES 

':'John E. Hay, CIRES 

,"Jerome K. Nimira, CIRES 

':'Graeme I . Pea rOlan, ClRES 

Constance Shilvock, Jr. Fellow 

Acguisition and Data Management Group 

*Gary A. Herbert, Chief 

Arija Bottomley, Clerk 

Connie Carla, Secretary 

*Joyce M. Harris, Computer Programmer 

Lee Johnson, Computer Programmer 

Milton S. Johnson, Electronic Te chnician 

James Jordan, Electronic Engineer 

Steven Waas, Jr. Fellow 

Monitoring Trace Gases Group 

*Walter D. Komhyr, Chief 

Connie Carla, Secretary 

*Robert D. Grass, Physicist 

*Thomas B. Harris, Meteorological Techni cian 

*Samuel Oltmans, Physicist 

Frank Polacek III, Meteorological Technician 

Thayne Thompson, Physicist 

*Lee Waterman, Chemist 

;'Ellsworth Dutton, CIRES 

Robert Evans, ClRES 

Valentine Szwarc, ClRES 

;'William Taylor, CIRES 

Aerosols and Radiation Monitoring Group 

*John J. DeLuisi, Chief 

*Barry A. Bodhaine, Meteorologist 

*Ronald W. Fegley, Physicist 

Gail M. Phillips, Secretary 

Analysis and Interpretation Group 

*James T. Peterson, Chief 

*Douglas V. Hoyt, Physicist 

Gail M. Phillips, Secretary 

Cheryl Reynolds, Jr. Fellow 

Thomas Stoffel, CIRES 

130 
auna Loa Observatory 

*Kinsell L. Coulson, Director 

*John F. S. Chin, Physicist 

*Richard S . Cram, Meteorologist 

*Howard Ellis, Physicist 

*Duane Harding, Me teorologis t 

Judith B. Pereira, Secretary 

Mamoru Shibata, Electroni c Technician 

*Alan M. Yos hinaga, Analytical Chemist 

Barrow Observatory 

··'Thomas DeFoor, Lt. NOAA Corps, Station Ch i ef 

Bradley C. Halter, Electronic Technician 

Steven Hill, Electronic Technician 

Samoa Observatory 

*Donal d W. Nelson, Station Chief 

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South Pole Observatory 

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,"Contributors to Summary Report 

131 

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