z 

NASA Contractor Report 178244 

, .' SAM I1 and SAGE Data Management 

and Processing 

M. T. Osborn 

C. R. Trepte 

ST Systems Corporation (STX) 

17 Research Drive 

Hampton, VA 23666 

Contract NASL-17165 

February 1987 

(NASA-CR-178244) SA!! r^ AliE SAGk LATA N87-15535 

MANAGEHEYT AblD E6CCESSING (53 Zystelas Corp.) 

62 p CSCL 04A 

Unclas 

G3/40 43612 

c 

NASA 

National Aeronautics and 

Space Administration 

Langley Research Center 

Hampton, Virginia 23665-5225 
PREFACE 

This report describes the data management and processing supplied by 

ST Systems Corporation (STX) for the SAM I1 and SAGE experiments under 

contract No. NAS1-17165 for the years 1983-1986. The report includes 

discussions of data validation, documentation, and scientific analysis, as 

well as the archival schedule met by the operational reduction of SAM 11 and 

SAGE data. The following STX employees have contributed to this contract: 

D. Brandl, J. C. Larsen, M. T. Osborn, M. W. Rowland, T. J. Swissler, and 

C. R. Trepte. 

i 
TABLE OF CONTENTS 

PAGE 

1.1 Introduction........~.e~.e.e...............~..~~...o..... 1-1 

1.2 Data Management and Processing 1-2 

1.2.1 General Discussion................................ 1-2 

.......................... 1.2.2 Quality Control.................................. 1-5 

1.2.3 Archival Schedule........... 1-6 

1.2.4 Quick-look Program............................... 1-6 

1.3 Data Validation......................................... 1-7 

1.4 Documentation........................................... 1-8 

1.5 Data Analysis.............. ............................. 1-10 

1.6 Concluding Remarks...................................... 1-14 

..................... 

2.1 Introduction............................................ 

2.2 Data Management and Processing.......................... 

2.2.1 General Discussion............................... 

2.2.2 Quality Control.................................. 

2.2.3 Archival Schedule................................ 

2.3 Data Validation ......................................... 2.3.1 Aerosol Validation............................... 

2.3.2 Ozone Validation................................. 

2.3.3 NO2 Validation................................... 

2.4 Documentation..............................~~.....~..... 

2.5 Data Analysis........................................... 

2.6 Concluding Remarks........................................ 

2-1 

2-2 

2 -2 

2-5 

2-5 

2-6 

2 -6 

2-7 

2 -9 

2-9 

2-10 

2-1 2 

SECTION 3 - PUBLICATIONS/PRESENTATIONS.................~~........ 3-1 

APPENDIX B SAGE PROFILE DATA USER'S GUIDE................... B-1 

iii 
SECTION 1 - SAM I1 

1.1 Introduction 

ST Systems Corporation (STX) supplied software support under contract 

NAS1-17165 for Stratospheric Aerosol Measurement (SAM) I1 data management, 

reduction, validation, display and analysis. 

The SAM I1 sensor is flying aboard the Earth-orbiting Nimbus 7 spacecraft 

and is designed to provide extinction measurements of the Antarctic and Arctic 

stratospheric aerosol with a vertical resolution of 1 km. 

instrument consists of a single-channel sunphotometer centered at a wavelength 

of 1.0 pm. 

(approximately 14 each per day). 

1978 and continues to provide excellent data after more than 8 years of 

operation. 

The SAM I1 

Data is collected during each spacecraft sunrise or sunset 

SAM 11 began collecting data in October, 

A large quantity of SAM I1 satellite data was processed under this 

contract, resulting in the archival of the first seven years of SAM I1 data. 

Quality control checks revealed that the large aerosol concentrations 

following the April 1982 eruption of El Chichon produced errors in the 

processed data for the fifth year only. Algorithms were modified and the 

fifth year data was reprocessed. 

verified the quality of these data. 

Similar checks on the fourth and other years 

Software was developed to process SAM I1 "quick-look" data so that SAM 11 

data could be available within 24 hours to direct real-time scientific 

investigations. An extensive validation program was carried out using the 

Langley airborne lidar system. The first four years of SAM I1 data have been 

summarized in a series of NASA Reference Publications, covering 6 months 

each. Data analysis has resulted in several important studies dealing with 

1-1 
polar stratospheric clouds, the polar vortex, the long term optical depth 

record in the polar regions and the effects of El Chichon. 

The following section of this report is an overview of the role of 

ST Systems Corporation (STX) in the successful reduction and validation of the 

first seven years of SAM I1 data. 

presentations supported under this contract has been included in section 111. 

In addition a list of publications and 

1.2 Data Management and Processing 

1.2.1 General Discussion 

Goddard Space Flight Center (GSFC) combines SAM I1 telemetry data, 

spacecraft time corrections, orbital ephemeris data and solar location 

information on an Image Location Tape (ILT) which is sent to NASA Langley 

Research Center (LaRC) for science processing. A tape containing 

meteorological data (MET) for each event is also received from the National 

Oceanic and Atmospheric Administration (NOM). 

Figure 1 presents an overview of the SAM I1 data processing at LaRC. 

Data is processed by ILT, i.e. a week at a time. 

meteorological, ephemeris and radiance data for each event are created and 

saved on tape. Transmission profiles are calculated and inverted to yield 

profiles of aerosol extinction. 

aerosol extinction are also saved on tape. 

Weekly files of merged 

Weekly files which include these profiles of 

SAM I1 processing yields two tape products which are sent to GSFC for 

eventual archival at the National Space Science Data Center (NSSDC). 

these tapes contain a month of data and are created by combining and 

reformatting the weekly files generated during initial processing. 

descriptions of these tapes are as follows: 

Both of 

Brief 

. 
1-3 
0 RDAT (Raw Data Archive Tape) 

This tape contains radiance data from each SAM I1 sunrise or sunset 

event as a function of time and tangent viewing location. 

BANAT (Beta-aerosol Number Density Archive Tape) 

This tape contains the derived aerosol extinction coefficients, 

atmospheric molecular extinction coefficients, and total extinction 

ratios as a function of altitude for each SAM I1 event. In addition, 

it also contained aerosol number density profiles and the optical 

models used to generate number densities from extinction coefficients 

for the first four years. Volcanic concentrations in year five 

invalidated these optical models. 

Team the aerosol number density profiles and optical models have been 

deleted from year five. 

On advice from the SAM I1 Science 

Each of these tapes is described in a tape specification document supplied by 

NSSDC when tapes are distributed. 

Two additional tape products were generated during processing of the 

first four years of SAM I1 data. 

the projected map matrices of derived SAM 11 parameters for plots of 

stereographic polar maps and cross sections of latitude (longitude) vs 

altitude. These tapes contained 3 months of data. PROFILE, SAM 11 Output 

Product Profiles Tape, contained the profiles of derived SAM I1 products and 

was generated monthly. 

processing by the Image Processing Division (IPD) at GSFC. 

the NASA technical representative, production of these tapes was discontinued. 

Plots of transmission and extinction profiles for every SAM I1 event were 

MATRIX, Mapped Data Matrix Tape, contained 

Both tapes were utilized for display product 

At the request of 

also generated at LaRC. These plots were transferred to microfiche for 
archival at LaRC and are used for quality control as well as scientific 

investigations of the data. 

1.2.2 Quality Control 

During the routine processing of SAM I1 data, screening reports are 

generated to detect various raw data and processing errors. 

error occurs the program software is corrected. After several years of 

successful data reduction, processing errors are very rare. Errors in the raw 

data, such as operational timing errors, cannot be corrected and result in 

loss of the event. Occasionally, large portions of raw data are in error. 

This occurred recently when Goddard changed computer systems and inadvertently 

altered the data on the ILTs. Data dumps were obtained and we were able to 

help Goddard correct these problems. As mentioned in section 1.2.1, plots of 

all SAM I1 extinction profiles have been saved on microfiche. 

scanning these profiles provides another means of quality control. 

When a processing 

Randomly 

In 1982 it was recognized that certain SAM I1 extinction profiles were 

affected by Earth Radiation Budget (ERB) calibration movements of the Nimbus 7 

spacecraft. A list of these profiles have been compiled and distributed with 

the archived data. 

additional anomalous extinction profiles were detected. These profiles led to 

the discovery that the scan altitudes were not being accurately determined 

following heavy stratospheric aerosol loading. In particular for the fifth 

year data set (November 1982-October 1983), the solar irradiance was 

attenuated below the detection threshold of the SAM I1 sensor at a height in 

the atmosphere that effected the sun shape-fitting techniques used to 

determine altitude. 

ephemeris calculations was developed and used to reprocess this data. This 

While screening the post El Chichon profiles, several 

A new technique to determine altitude using accurate 

1-5 
procedure was also applied to the fourth year data with the result the same as 

the initial processing. 

fifth year. 

The altitude correction was only significant for the 

Recently the entire SAM I1 data set was ecreened for bad profiles by 

plotting extinction isopleths on a daily basis as a function of altitude and 

longitude. These plots have been compiled, organized in bindings, labelled, 

and delivered to the Aerosol Research Branch (ARB) at NASA-LaRC. Individual 

profiles which are not consistent with adjacent profiles can be easily 

identified when plotted in this form. 

against microfiche plots of extinction and transmission. A list of anomalous 

profiles was generated for each of the first 7 years of SAM 11 data and this 

list is included as Appendix A of this report. 

Suspicious profiles are then checked 

1.2.3 Archival Schedule 

SAM I1 RDAT and BANAT tapes were sent to GSFC for archival at NSSDC 

according to the schedule in Table 1. 

1.2.4 Quick-look Program 

The SAM I1 quick-look program was developed to rapidly process data in 

support of real-time scientific investigations. This reduction method was 

designed to rely on just the actual satellite data. Predicted satellite 

location and model meteorological conditions were provided by the data 

reduction programs. From data collection to data interpretation, the period 

of elapsed time could range from six to twenty-four hours. 

program was used in several instances to provide near real-time guidance to 

correlative measurement aircraft. 

The quick-look 
Table 1: SAM I1 Data Archival Schedule 

Date Sent 

Data Coverage I RDATs BANATs 

Year 1 (November 1978-October 1979) 

Year 2 (November 1979-October 1980) 

Year 3 (November 1980-October 1981) 

Year 4 (November 1981-October 1982) 

Year 5 (November 1982-October 1983) 

Year 6 (November 1983-October 1984) 

Year 7 (November 1984-October 1985) 

December 1980 

November 1981 

March 1982 

May 1983 

May 1984 

January 1986 

June 1986 

May 1981 

November 1981 

May 1982 

May 1983 

May 1984* 

January 1986 

June 1986 

*Removed from archives (see 1.2.2). 

approval of the SAM I1 Project Scientist, Dr. M. P. McCormick, will be 

forwarded by ARB to the archival center. 

This data has been reprocessed and upon 

1.3 Data Validation 

SAM 11 was validated by a series of coordinated experiments using a 

variety of sensors. Table 2 lists these major correlative experiments. 

Work under this contract was confined mainly to SAM XI validation using 

the Langley airborne lidar system. The airborne lidar system, developed 

especially as a correlative sensor for satellite experiments, has four main 

advantages: 1) it can obtain data above cloud tops; 2) it can fly to 

satellite sensing locations; 3) it can sample a path similar to that viewed by 

the satellite; and 4) the data has good vertical resolution. 

The airborne lidar data was analyzed using the method described by 

Russell et al. (1979). Profiles of aerosol backscatter coefficient (l/km-sr) 

vs altitude at wavelength A= 0.6943pm were obtained. To compare these 

profiles with the A- 1.0 pm extinction (l/km) profiles measured by SAM 11, 

aerosol optical models were constructed. Dustsonde data, either coincident or 

modeled, were used to constrain these models and provide a method to convert 

1-7 
Table 2: SAM I1 Correlative Experiments 

Sensor 

Site Date Lidar Dustsonde SAGE Others 

Sondrestrom, November 22-25, 1978 X X X 

Poker Flat, July 16-19, 1979 X X X X 

Frobisher Bay December 14, 1980 X 

Sondrestrom, January 29 & 31, 1983 X 

Greenland 

Alaska . 

Canada 

Greenland February 2, 1983 

Sondrestrom, January 21, 23, 24, 1984 X 

Greenland 

backscatter coefficient to extinction during routine data processing. 

Comparisons obtained between SAM I1 and lidar-derived extinction profiles, 

with associated error bars, for the 1978 Sondrestrom, Greenland and 1979 Poker 

Flat, Alaska experiments have been described in Russell, et al. (1981a) and 

Russell, et al. (1984). All of the correlative experiments taken together 

provide convincing evidence for the validity of SAM I1 extinction 

measurements. 

1.4 Documentation 

A series of reference reports (Table 3) was prepared by ST Systems Corp. 

(STX) and published by NASA to present large amounts of atmospheric data 

collected by the SAM I1 satellite experiment in a convenient, ready-to-use 

visual format. The intent of these reports was to provide an overview of the 

observed data to facilitate use in atmospheric and climatic studies. A brief 

1-8 
summary was given describing the aerosol distribution in both polar regions 

for the period encompassed by each report, however, no detailed analysis or 

geophysical explanation of the data was provided. The SAM 11 reference 

publications were organized into separate volumes containing 6 months of 

measured aerosol data beginning from the launch of the Nimbus 7 spacecraft in 

October 1978. 

Since the incremental change in latitude between successive measurement 

locations is small, the averages taken over a period of a week represent zonal 

averages within a narrow latitude band. 

temporally to reduce the quantity of SAM I1 data into a managable form for 

presentation. Aerosol extinction profiles, with corresponding NOM 

temperature profiles, were separated into sunrise or sunset events before 

averaging over a period of a week. Typically, more than 90 individual 

profiles were included in the averaging process. These profiles were 

displayed in the reference publication with information about the variability 

of the averages provided by standard deviation and depicted as horizontal 

error bars. Vertical cross sections of the 1 pm aerosol extinction for a 1 

day period were shown as a function of longitude. The utility of these plots 

was to indicate the finer structure of the aerosol distribution and show when 

the zonal average is a poor representation of the observed data (i.e., inside 

and outside the stratospheric polar vortex). 

for presentation for each weekly period. The stratospheric aerosol optical 

depth value was determined from the SAM XI data and averaged in a similar manner. 

Consequently, the data was averaged 

Only a single day was selected 

During the 4 year period covered by this contract, 6 SAM XI reference 

publications were prepared, assembled, and submitted for publication. Table 3 

lists the volumes and the periods included by each report. 

1-9 
Table 3: SAM I1 Reference Publications 

Reference Publication 

RP 1081 

RP 1088 

RP 1106 

RP 1107 

RP 1140 

RP 1141 

RP 1164 

RP 1165 

(December 1981) 

(March 1982) 

(June 1983) 

(June 1983) 

(May 1985) 

(May 1985) 

(August 1986 ) 

(August 1986 ) 

~~ ~ 

Volume 

I 

TI 

I11 

IV 

V 

VI 

VI1 

VI11 

Coverage 

October 1978 - April 1979 

April 1979 - October 1979 

October 1979 - April 1980 

April 1980 - October 1980 

October 1980 - April 1981 

April 1981 - October 1981 

October 1981 - April 1982 

April 1982 - October 1982 

1.5 Data Analysis 

Over the period covered by this contract, a number of studies using SAM 

11 data were performed to further our understanding of the stratospheric 

aerosol distribution. Since the scope of these studies encompassed a wide 

range of topics, the following discussion summarizes some of the results 

revealed by SAM I1 observations. 

Figure 2 shows the 1.0 pm stratospheric optical depth record obtained in 

both polar regions for a 7 year period (McCormick and Trepte, 1986a). 

weekly averaged data show that the overall yearly values in the two polar 

regions are influenced by seasonal variations and controlled by volcanic 

perturbations. During this period (late 1978 through October 1985), the 

Arctic region experienced the effects of a number of eruptions, most of which 

occurred in the northern hemisphere. 

1982, however, created the largest enhancement in optical depth recorded in 

both hemispheres, with peak optical depth values of 5.5 x in the Arctic 

region and 2.0 x 10-2 in the Antarctic region. 

conservative values because of instrument limitations at such high aerosol 

loadings, with a more representative estimate of approximately 0.11 for the 

The 

The eruption of El Chichon in April 

Both are felt to be 

1-10 
I 

IW 

n 

n 

-ma Q -alp P (u -a@ P (u- (u 

- f Iu n h h 0 0 

Hld30 lV’311d0 

1-11 
Arctic region and 2.6 x for the Antarctic region. 

Correlation of the optical depth record with a similar record of 50 mb 

temperatures, shown in Figure 3, indicates periodic intervals when 

enhancements in aerosol extinction produce as much as an order of magnitude 

higher optical depth values than observed during the previous summer season. 

These episodes are due to the formation of PSC’s which themselves are a 

manifestation of the microphysical growth of the background sulfuric-acid 

aerosol particles during periods with mean temperatures <195 K. 

the SAM I1 data shows that Antarctic PSC’s are present for periods of about 3 

months, from June until early September. Further investigation reveals a 

vertical variation of high aerosol optical properties (inferred to be PSC’s) 

during this same interval for each year. This variation is believed to be due 

in part to particle sedimentation, particle evaporation, and subsidence. 

Recent theories employing PSC formation to help explain the ozone hole during 

the austral spring must account for the observed behavior of these 

measurements (McCormick and Trepte, 1986b). 

each Arctic winter, but are much less frequent due to the warmer conditions 

present in the average northern winter stratosphere. Synoptic analysis of the 

SAM I1 observations reveals a non-zonal structure in aerosol properties during 

the winter hemisphere, especially in the Arctic region where planetary wave 

activity is pronounced. 

Analysis of 

Arctic PSC’s are also observed in 

Another recurring feature in the SAM I1 data (Figure 2) is the depression 

in optical depth observed in late September and early October in the southern 

hemisphere immediately following the disappearance of PSC’s at the latitudes 

measured by SAM 11. It is believed that this relative minima is produced by 

the loss of aerosols within the vortex by both gravitational settling of the 

PSC ice particles during the coldest segment of winter and the general 
. 

I I I I41 I I I I 

Om - 8 N 

I0 0 0 0 AI 0 Om n 

rc) 

N 

W 

N \Y 

cu 

ua c 

Pd orl al 

os 

rnrnu 

1-13 
subsidence of air induced by the mean diabatic circulation. This behavior was 

elucidated in a study (McCormick et al., 1983) of the aerosol distribution for 

a winter season in the northern hemisphere polar region. It was found that 

within the polar vortex, a systematic lowering of aerosols inside the vortex 

created a strong gradient in aerosol properties across the polar night jet 

stream. Air parcels within the vortex remained relatively isolated from 

transport on the anticyclonic side of the jet stream until the vortex 

disappeared in late March. The lowering of aerosols inside the vortex is 

inferred to be caused by the descending branch of the mean diabatic 

circulation at high latitudes (Kent et al., 1985). A similar process should 

be present in the southern hemisphere as indicated by circulation calculations 

(Trepte, 1986). Therefore, changes in the aerosol structure that took place 

within the vortex by these processes are maintained until the vortex breaks 

up, usually about November when increases in aerosol optical depth are 

observed as aerosol from lower latitudes move into these higher latitudes. 

The impact of volcanic eruptions as seen in Figure 2 is much more 

apparent in the northern high latitudes, partly because of the greater number 

of eruptions that occurred in the northern hemisphere during this period and 

partly because of the favorable seasonal circulation patterns following these 

eruptions. With the eruption of El Chichon, optical depth values in the 

Arctic latitudes were conservatively about 40 times greater than the near 

background observations in 1978. 

8 

1.6 Concluding Remarks 

The contract period has seen the successful management, reduction, 

validation and archival of the fourth, sixth, and seventh years of SAM IT 

data. The fifth year of SAM I1 data, which was most heavily contaminated by 

1-14 
stratospheric aerosol loading from El Chichon, has been reprocessed. The 

fourth year data was also reprocessed with no change from the initial 

processing. Altitude corrections resulting from large volcanic concentrations 

were significant only for the fifth year data set. In addition, transmission 

and extinction profiles for every SAM I1 event have been plotted and saved on 

microfiche. The first four years of SAM I1 data have been summarized in a 

series of NASA Reference Publications. 

were performed to further our understanding of the stratospheric aerosol 

distribution (Section 3). 

A number of studies using SAM I1 data 

1-15 
SECTION 2 - SAGE 

2.1 Introduction 

ST Systems Corporation (STX) supplied software support 

NAS1-17165 for the Stratospheric Aerosol and Gas Experiment 

management, reduction, validation, display and analysis. 

under contract 

(SAGE) data 

SAGE was launched February 18, 1979 on a dedicated Applications Explorer 

Mission (AEM-B) satellite. The SAGE orbit, selected to complement SAM I1 

geographical coverage, allowed for collecting measurements, with some seasonal 

variation, between 72% and 72's. 

photometer centered at the wavelengths: 0.385 pm, 0.45 pm, 0.60 pm and 

1.0 pm. 

of ozone and NO2 concentration and aerosol extinction (1.0 pm and 0.45 urn). 

Up until July 1979, data was collected during each spacecraft sunrise and 

sunset (approximately 15 each per day). At that time sunrise measurements 

were discontinued because of a problem with the spacecraft batteries. SAGE 

ceased taking measurements in November 1981. 

The SAGE instrument was a four-channel sun 

The radiances obtained were mathematically inverted to yield profiles 

The third year SAGE satellite data was processed under this contract, 

resulting in the archival of all three years of SAGE data. Subsequently, it 

was learned that the NOAA supplied meteorological data used in the processing 

was in error above 10 mb. All three years of SAGE data were recomputed using 

a NOAA supplied temperature bias correction and rearchived. 

An extensive aerosol validation program was carried out using the Langley 

airborne lidar system. SAGE ozone data was validated through comparisons with 

numerous ECC and MAST balloonsondes, chemiluminescent rocketsondes, and 

optical rocketsondes. The SAGE aerosol data has been summarized in a series 

of 3 NASA Reference Publications (NASA RP 1144, 1149 and 1173). The SAGE 

2 -1 
ozone and NO2 data will be summarized by NASA-LaRC in a similar series of 

Reference Publications. 

aerosols and dynamically controlled ozone. 

I 

Data analysis has examined the transport phenomena of 

The following section of this report is an overview of the role of 

ST Systems Corporation (STX) in the successful reduction and validation of the 

SAGE data. 

under this contract has been included in section 111. 

In addition a list of publications and presentations supported 

2.2 Data Management and Processing 

2.2.1 General Discussion 

GSFC combined and reformatted SAGE telemetry data for each day to create 

an experimenter tape (EXP) which was sent to LaRC for instrument 

"housekeeping" checks and science processing. GSFC also supplied a weekly 

tape of ephemeris information (EPH). A tape containing meteorological data 

(MET) for each event was received from NOAA. 

Figure 4 presents an overview of the SAGE data processing at LaRC. Each 

experimenter tape was copied onto an internal tape at the LaRC computer 

center. Then 4-day files of merged meteorological, ephemeris and radiance 

data for each event (MERDATs) were created and saved on tape. Transmission 

profiles were calculated and inverted to yield profiles of extinction at all 4 

wavelengths. 

period were also saved on tape. 

Files which included these extinction profiles for each 4-day 

SAGE processing yielded three tape products: MERDAT and PROFILE tapes, 

which were sent for archival at NSSDC, and OZONE tapes, which were sent to the 

World Ozone Data Center (WODC). 

processing. PROFILE tapes, which contain a month of data, were created by 

combining and reformatting the 4-day files of inverted data generated during 

MERDAT tapes, were generated during initial 

2 -2 
-T9) 

ou 

U d 

h(d 

ac 

OU 

UP) u 

C 

Ti 

4 

' 

A 

a" 

m 

m 

.. 

a 

(d 

u 

(d 

a 

W 

0 

3 

0 

rl 

r.4 

U 

r.4 

2 -3 
initial processing. 

by stripping out and reformatting the ozone data on the PROFILE tapes. Brief 

descriptions of these tapes are as follows: 

OZONE tapes also contain a month of data and were created 

0 MERDAT (Meteorological Ephemeris Radiance Data Archive Tape) 

This tape contains meteorological, ephemeris and slow-scan 

radiance data for each SAGE sunrise or sunset event. 

0 PROFILE Tape 

This tape contains processed SAGE data including profiles of 

aerosol, ozone, and NO2 extinction, ozone and NO2 number density, 

1.0 urn extinction ratio, and ozone and NO2 volume mixing ratio, along 

with corresponding estimates of error at each altitude. 

0 OZONE Tape 

This tape contains only the SAGE ozone data which was contained on 

the PROFILE tape. 

PROFILE tapes were generated at LaRC and distributed to all Science Team 

members and other interested scientists under this contract. The Profile Data 

User’s Guide, written to describe the data on the PROFILE tape, has been 

included in Appendix B. 

Plots of extinction profiles at the four SAGE wavelengths for every SAGE 

event were also generated at LaRC. These plots were transferred to microfiche 

for archival at LaRC and are used for quality control as well as scientific 

investigations of the data. 
2.2.2 Quality Control 

During the routine processing of SAGE data, screening reports were 

generated to detect various raw data and processing errors. 

error occurred, the program software was corrected. Errors in the raw data, 

such as timing errors, could not be corrected and resulted in the loss of an 

event. As mentioned in section 2.2.1, plots of all SAGE extinction profiles 

have been saved on microfiche. Randomly scanning these profiles provided 

another means of quality control. 

When a processing 

Data Coverage 

Year 1 (February - December 1979) 

Year 2 (January - December 1980) 

Year 3 (January - November 1981) 

2.2.3 Archival Schedule 

SAGE MERDAT and PROFILE tapes were sent to NSSDC and SAGE OZONE tapes 

were sent to WODC according to the schedule in Table 3. 

Data Sent 

MERDATS Profile Tapes Ozone Tapes 

May 1981 June 1982* January 1983** 

October 1981 December 1982* January 1983** 

March 1983 June 1983* ** 

Table 3: SAGE Data Archival Schedule 

*In August 1984 SAGE data was recomputed using the NOAA temperature bias 

correction. All three years of SAGE PROFILE tapes were rearchived in March 

1985. 

**The third year OZONE tapes had not been sent when the temperature bias 

correction became available. 

of the SAGE Project Scientist, Dr. M. P. McCormick, will be forwarded by ARB 

(NASA-LaRC) to the archival center. 

The data has been reprocessed and upon approval 

2 -5 
2.3 Data Validation 

2.3.1 Aerosol Validation 

SAGE aerosol data was validated by a series of coordinated experiments 

using a variety of sensors. Table 4 lists these major correlative 

experiments. 

Table 4: SAGE Aerosol Correlative Experiments 

Palestine, 

Texas - ~~~~~~~ 

Wallops Island, 

Virginia 

Natal, Brazil 

Poker Flat, 

Alaska ~ 

Wallops Island, 

Virginia 

Wallops Island, 

Virginia 

Portland, 

Oregon 

Plattsburg, 

New York 

Date 

March 12-13, 1979 

~~ ~~ 

April 5, 1979 

April 12-14, 1979 

July 16-19, 1979 

October 31- 

November 2, 1979 

May 27-28, 1980 

September 19-20, 198( 

December 9-10, 1980 

Sensor 

Aerosol validation under this contract was confined mainly to comparisons 

between SAGE and the airborne lidar system. The airborne lidar data was 

analyzed using the method described by Russell et al. (1979). Profiles of 

2 -6 
aerosol backscatter coefficient (l/km-sr) VS. altitude at wavelengths 

X = 1.06 pm and X = 0.6943 Pm were obtained. 

the X = 1.0 pm and = 0.45 Pm extinction (l/km) profiles measured by SAGE, 

aerosol optical models were constructed (Russell et al., 1981b). Dustsonde 

data, either coincident or modeled, were used to constrain these models and 

provide a method to convert backscatter coefficient to extinction during 

routine data processing. Comparisons obtained between SAGE and lidar-derived 

extinction profiles, with associated error bars, for the 1979 Poker Flat, 

Alaska experiment were described in Russell, et al. (1984). All of the 

correlative experiments taken together provided convincing evidence for the 

validity of SAGE extinction measurements. 

To compare these profiles with 

2.3.2. Ozone Validation 

A comprehensive series of correlative experiments was conducted during 

1979-1980 at five fixed sites between 6'sand 65'N to test the validity of 

SAGE ozone data. The intercomparisons included data taken with 

electrochemical ozone (ECC) balloonsondes and chemiluminescent and optical 

rocketsondes. Table 5 lists these correlative experiments. Under this 

contract, comparisons were made between SAGE and each of the 17 ECC 

balloonsondes, 3 chemiluminescent rocketsondes and 2 optical rocketsondes. 

Ozone volume mixing ratio was the parameter chosen for comparison. The 

average mean absolute difference over all these comparisons was 10.4%. 

detailed description of these comparisons is found in McCormick, et al. 

(1984). 

A more 

A similar series of correlative measurements was conducted from European 

stations during the same period. 

balloon ozonesondes yielded an average mean absolute difference of 8.8%. 

Comparisons between SAGE and each of 30 

A 

2-7 
Table 5: SAGE Ozone Correlative Experiments 

~~ ~~ ~ 

Palestine, March 13, 1979 X(2 

Texas 

Site 

~ ~~ ~ ~ 

Poker Flat, July 19, 1979 X(2 

Wallops Island, August 22, 1979 X(2) 

Wallops Island, November 1, 1979 X 

Natal, Brazil February 19, 1980 X 

Alaska 

Virginia 

Virginia 

Date 

~ ~~~~~ ~ 

Palestine, 

Wallops Island, 

Palestine, 

Primrose Lake, 

Poker Flat, 

Texas 

Virginia 

Texas 

Canada 

Alaska 

April 5, 1979 X 

April 5, 1979 W) 

April 6, 1979 X(2 1 

May 3, 1979 X 

July 16, 1979 X(2) 

Poker Flat, 

Alaska 

July 17, 1979 X 

Sensor 

optical Chemic a 1 

Rocket Rocket 

X 

Ix 

Ix 

more detailed description of these comparisons is found in Reiter and 

McCormick (1982). Considering the difference in vertical resolution, 

experimental errors, and ozone time and space gradients, the agreement between 

SAGE ozone data and both sets of correlative measurements was considered very 

good. 

2-8 
2.3.3 NO2 Validation 

Extremely low values of NO2 measured by the SAGE instrument inside the 

southern vortex were recently investigated. NO2 extinction versus altitude 

was derived using an onion peel occultation retrieval from SAGE slant path 

transmittance in the 0.385 pm and 0.45 pm channels for several days. The 

inferred extinction was found to be very sensitive to temperature as a result 

of the Rayleigh scattering correction in both channels. It was concluded that 

the extremely low values of NO2 may be due to temperature uncertainties. 

2.4 Documentation 

A series of reference documents were prepared by ST Systems Corporation 

(STX) to present SAGE aerosol and gaseous data in a convenient and ready-touse visual format. These reports are organized into 2 separate series: one 

containing aerosol data and the other containing O3 and NO2 observations. 

Each report spans a single calendar year for 1979, 1980, and 1981. The intent 

of these publications is to provide a broad overview of the measured 

parameters without giving a detailed geophysical explanation of the 

observations. 

Unlike the SAM 11 experiment, the SAGE spacecraft had orbital 

characteristics which permitted the instrument to sample a larger latitude 

range. This additional coverage required the data to be presented in a manner 

representative of the geophysical distribution. Consequently, the data was 

presented by zonal averages instead of weekly averages. A table and series of 

figures was given to indicate the latitude of measurement as a function of 

time. In general, the SAGE sunrise or sunset data were presented separately 

by latitude sweeps. A sweep is defined as the set of data obtained during a 

maximum-to-maximum (north-to-south or south-to-north) latitudinal measurement 

2-9 
sequence. Specifically, for the SAGE Aerosol Reference Publication results 

consist of: (1) tables of extinction and temperature as a function of 

altitude, (2) plots of average extinction and temperature profiles, (3) daily 

vertical cross sections of extinction as a function of longitude (4) plots of 

zonally averaged extinction and temperature per sweep, (5) tables of 

seasonally averaged extinction and temperature data, (6) plots of seasonally 

averaged extinction and temperature, and (7) tables of stratospheric optical 

depth per sweep at various latitudes and longitudes. To date, NASA RP 1144 

for 1979 and NASA RP 1149 for 1980 SAGE aerosol measurements have been 

published. The Reference Publication for Volume I11 of the SAGE aerosol (NASA 

RP 1173) has been accepted and will be published in early 1987. 

For the SAGE Gas Reference Publications, the results consist of (1) 

tables of concentration, mixing ratio, and temperature, (2) plots of average 

concentration, mixing ratio, and temperature profiles, (3) plots of zonally 

averaged concentration, mixing ratio, and temperature per sweep, (4) tables 

and plots of seasonally averaged concentrations, and mixing ratio, and (5) 

tables of integrated column O3 and NO2 per sweep at various latitudes and 

longitudes. The first SAGE Gas Reference Publication has been submitted to 

NASA for acceptance. 

2.5 Data Analysis 

Analysis of SAGE data during this contract period has focused on 

transport phenomena in the stratosphere. These studies examined the poleward 

movement of aerosols and dynamically controlled ozone. The injection of 

volcanic material into the stratosphere facilitates the tracking of air masses 

latitudinally. Under periods of strong planetary wave activity, rapid 

poleward transport of enhanced aerosols was observed along zonal mean 
isentropic surfaces, as seen a month after the eruption of Sierra Negra in 

November 1979. 

summer), the SAGE data showed that the redistribution of volcanic debris 

remained confined to narrow bands in latitude. Unlike the meridional 

structure of aerosols which were transported poleward rapidly, the nearbackground or aged aerosol distribution exhibited a structure with contours 

intersecting zonal mean potential temperature surfaces. It is believed that 

this behavior reflects the diabatic processes present in the meridional 

During periods of little planetary wave activity (i.e. 

circulation. Information obtained from these analyses was used to support 

more detailed investigations using SAM I1 data of vertical transport in polar 

regions (i.e., Kent et al., 1985). 

Other evidence of vertical air motion was inferred from measurements of 

anomalously high aerosol extinction values in the lowest layers of the 

tropical tropopause. It is widely accepted that the rising branch of the 

diabatic circulation is located in the tropics, but the mechanism by which 

tropospheric air enters the stratosphere is not clear. Overshooting 

thunderstorms may be a conduit for vertical transport. However, these 

convective cells must be located in regions with low enough tropopause 

temperatures to preserve the arid conditions of the stratosphere. A study 

examined the occurrence of high aerosol extinction episodes not associated 

with volcanic eruptions and found that the greatest frequency of these 

'clouds' is located in convectively active regions and varies geographically 

with season. Furthermore, these regions had tropopause temperatures 

consistent with the observed frost point of the lower stratosphere (Trepte, 

1983). 

2-11 
2.6 Concluding Remarks 

This contract has seen the successful management, reduction, validation 

and archival of all SAGE data. In addition extinction profiles, at each of 

the 4 SAGE wavelengths, for every SAGE event have been plotted and saved on 

microfiche. The SAGE aerosol data have been summarized in a series of NASA 

Reference Publications. 

will be published by LaRC in RP’s. 

phenomena in the stratosphere. 

The SAGE gas data have been similarly organized and 

Data analysis has focused on transport 
SECTION 3 - PUBLICATIONS/PRESENTATIONS 

. 

ST Systems Corporation (STX) employees participated in the writing of 

several papers during the contract period. The following list includes the 

most significant of these, plus a few selected earlier publications. 

Kent, G. S., Trepte, C. R.*, Farrukh, U. O., McCormick, M. P.: Variation in 

the Stratospheric Aerosol Associated with North Cyclonic Polar Vortex as 

Measured by the SAM I1 Satellite Sensor. J. Atmos. Sei.,%, 14, July 1985. 

McCormick, M. P.: SAGE Aerosol Measurements, Volume I - February 21, 1979 - 

December 31, 1979. NASA RP 1144, October 1985. 

McCormick, M. P.: SAGE Aerosol Measurements, Volume I1 - January 1, 1980 - 

December 31, 1980. NASA RP 1149, January 1986. 

McCormick, M. P.: SAGE Aerosol Measurements, Volme I11 - January 1, 1981 - 

November 18, 1981. NASA RP 1173, February 1987. 

McCormick, M. P.: SAM I1 Measurements of the Polar Stratospheric Aerosol. 

Vol. I - October 1978 to April 1979. NASA RP 1081, December 1981. 

McCormick, M. P., and Brandl, David*: SAM I1 Measurements of the Polar 

Stratospheric Aerosol. Vol. 111 - October 1979 to April 1980. NASA RP 1106, 

June 1983. 

*Denotes ST Systems Corporation (STX) employee. 

3-1 
McCormick, M. P., and Brandl, David*: SAM I1 Measurements of the Polar 

Stratospheric Aerosol. Vol. IV - April 1980 to October 1980. NASA RP 1107, 

June 1983. 

McCormick, M. P., and Brandl, David*: SAM 11 Measurements of the Polar 

Stratospheric Aerosol. Volume V - October 1980 to April 1981. 

May 1985. 

NASA RP 1140, 

McCormick, M. P., and Brandl, David*: SAM I1 Measurements of the Polar 

Stratospheric Aerosol. Volume VI - April 1981 to October 1981. NASA RP 1141, 

May 1985. 

McCormick, M. P., and Brandl, David*: SAM I1 Measurements of the Polar 

Stratospheric Aerosol. Volume VI1 - October 1981 to April 1982. NASA RP 

1164, August 1986. 

McCormick, M. P., and Brandl, David*: SAM I1 Measurements of Polar 

Stratospheric Aerosol. Volume VI11 - April 1982 to October 1982. NASA RP 

1165, August 1986. 

McCormick, M. P., and Larsen, J. C.*: Antarctic Springtime Measurements of 

Ozone, Nitrogen Dioxide, and Aerosol Extinction by SAM 11, SAGE and SAGE 11, 

Geophys. Res. Lett., - 13, pp. 1280-1283, 1986. 

McCormick, M. P., Steele, Helen M.*, and Hamill, Patrick*: SAM I1 Measurement 

of the Polar Stratospheric Aerosol. Vol. TI - April 1979 to October 1979. 

NASA RP 1088, March 1982. 
. 

McCormick, M. P., Steele, H. M.*, Hamill, P.*, Chu, W. P., and Swissler, T. 

J.*: Polar Stratospheric Cloud Sightings by SAM 11. J. Atmos. Sci., _. 39, 6, 

ppe 1387-1397, 1982. 

McCormick, M. P., Swissler, T. J.*, Hilsenrath, E., Krueger, A. J., and 

Osborn, M. T.*: Satellite and Correlative Measurements of Stratospheric 

Ozone: Comparison of Measurements Made by SAGE, ECC Balloons, 

Chemiluminescent, and Optical Rocketsondes. J. Geophys. Res., 89, D4, pp. 

5315-5320, June 30, 1984. 

McCormick, M. P. and Trepte, C. R.*: Polar Stratospheric Optical Depth 

Observed by the SAM I1 Satellite Instrument Between 1978 and 1985. - J. 

Geophys. Res., (accepted, 1987). 

McCormick, M. P., and Trepte, C. R.*: SAM I1 Measurements of Antarctic PSC’s 

and Aerosols. Geophys. Res. Lett., 13, pp. 1276-1279, 1986. 

McCormick, M. P., Trepte, C. R.*, and Kent, G. S.: Spatial Changes in the 

Stratospheric Aerosol Associated with the North Polar Vortex. Geophys. Res. 

Lett ., -, 10 pp. 941-944, 1983. 

Reiter, R., and McCormick, M. P.: SAGE-European Ozonesonde Comparison. 

Nature, 300, 5890, pp. 337-339, 1982. 

Russell, P. B., McCormick, M. P., and Swissler, T. J.*: Validation of Aerosol 

Measurements by the Satellite Sensors SAM 11 and SAGE. Adv. Space Res., - 2, 5, 

pp. 123-126, 1983. 

3-3 
Russell, P. B., McCormick, M. P., Swissler, T. J.*, Chu, W. P., Livingston, J. 

M., Fuller, W. H., Jr., Rosen, J. M., Hofmann, D. J., McMaster, L. R., Woods, 

D. C., and Pepin, T. J.: Satellite and Correlative Measurements of the 

Stratospheric Aerosol 11: Comparison of Measurements Made by SAM 11, 

Dustsondes and an Airborne Lidar. 

1981a. 

J. Atmos. Sci., 38, 6, pp. 1295-1312, 

Russell, P. B., McCormick, M. P., Swissler, T. J.*, McMaster, L. R., Rosen, J. 

M. and Hofmann, D. J.: Satellite and Correlative Measurements of the 

Stratospheric Aerosol 111: Comparison of Measurements by SAM 11, SAGE, 

Dustsondes, Filters, Impactors and Lidar. J. Atmos. Sci., - 41, 11, pp. 1791- 

1800, 1984. 

Russell, P. B., Swissler, T. J.*, and McComick, M. P.: Methodology for Error 

Analysis and Simulation of Lidar Aerosol Measurements. 

3783-3797, 1979. 

Appl. Opt., 18, pp. 

Russell, P. B., Swissler, T. J.*, McCormick, M. P., Chu, W. P., Livingston, J. 

M., and Pepin, T. J.: Satellite and Correlative Measurements of the 

Stratospheric Aerosol I: - An Optical Model for Data Conversions. J. Atmos. 

-- Sci., 38, 6, pp. 1279-1294, 1981b. 

Steele, H. M.*, Hamill, P.*, McCormick, M. P., and Swissler, T. J.*: The 

Formation of Polar Stratospheric Clouds. J. Atmos. Sci., - 40, 8, pp. 2055- 

. 

2067, 1983. 
Trepte, C. R.*: Variation in Polar Stratospheric Aerosol During the Southern 

Winter of 1984. 

Meteorological Society, Williamsburg, Virginia, May 13-16, 1986. 

Presented at Sixth Conference on Atmospheric Radiation of the 

Trepte, C. R.* and McCormick, M. P.: Observations of Cirrus in the Lower 

Tropical Stratosphere. 

of the Upper Atmosphere, Boston, Massachusetts, March 22-25, 1983. 

Am. Meteorol. SOC. 4th Conference on the Meteorology 

3 -5 
APPENDIX A 

SAM I1 QUALITY CONTROL 
SAMII QUALITY CONTROL 

Anomolous extinction profiles have recently been found 

in the SAMII data set covering the period from the middle of 

1982 through 1983. While some of these profiles exhibit the 

high extinctions characteristic of ERB calibrations.the 

remainder of the questionable profiles appear to be related 

to problems with determining the correct scan altitude 

during periods of heavy stratospheric aerosol loading. To 

determine the extent of the problem the entire SAMII data 

base has been screened for bad profiles by plotting 

extinction isopleths on a daily basis as a function of 

altitude and longitude. Individual profiles which are not 

consistent with adjacent profiles(either in time or 

longitude) can be easily identified when plotted in this 

form. Suspicious profiles are then checked against the 

microfiche plots of extinction and transmission. Although 

this visual screening process is somewhat subjective we are 

primarily concerned with those profiles which are obviously 

incorrect. Instances vhere the profiles are questionable 

but it was not possible to reach a definite conclusion are 

also listed in the following tables. The user should 

inspect these profiles and decide whether or not they are 

suitable to be included in the particular study being 

undertaken. The anomolous profiles have been categorized in 

the tables as followS: 
CAUSE 

E ERB calibration. Delete all of these profiles. 

E+ Extinction profile is similar to that for an ERB 

calibration but the profile shape suggests there are 

additional problems. Delete all of these profiles. 

Sun spots. These appear to be a problem only from 20 

to 3Okm and above. Whether or not these profiles 

should be deleted depends on how the SAM11 data is 

being used. Only the worst cases have been listed 

in the tables. There are many more profiles remaining 

in the data base which are slightly perturbed by sun 

SP 

spots . 

ADB Altitude determination is bad. The qualifier 

(described below) determines whether the profile 

should be deleted. 

? Cause unknown. Qualifier determines whether the 

profile should be deleted. 

QUALIFIER 

D Delete profile from consideration. 

? End user must decide whether or not to delete profile. 

Astericks following the orbit numbers in the following 

tables indicate those profiles which have been identified 

previously as perturbed by an ERB calibration. Days for 

which no profiles are available are listed at the end of 

each yearly table. These tables will be updated as new data 

A-3 
is processed or old data reprocessed. 

Jack Larsen 

Last revision 9/15/85 

Data screened through 5/5/84 

Last revision 3/06/86 

Data screened through 5/4/85,Week 341 

Last revision 5/23/86 

Data screened through 10/26/85,Week 366 

A-4 
1978 

ORBIT 

NUMBER MONTHIDAY 

253 NOV/11 

490 * NOV/28 

?97* DEC / 20 

WEEK / DOY 

3/315 

6/332 

91354 

0-SR(S) 

l-SS(N) CAUSE 

1 ADB(D) 

0 E 

1 E 

A-5 
1979 

ORBIT 

NUMBER 

1073 

1552* 

1766 

1773* 

1987 

2105* 

2105* 

2568 * 

2568* 

2836 

2928 * 

3259* 

3259* 

3591 * 

3591 * 

3923* 

4254* 

4586 * 

4586* 

4691 

5097 * 

5130 

5249* 

5560* 

5581* 

5915* 

MONTH 1 DAY 

JAN109 

FEB113 

MAR101 

MARIO1 

MAR117 

MAR125 

MAR125 

APR128 

APR128 

MAY I 17 

MAY 1 24 

JUN117 

JUN1 17 

JUL1 11 

JUL111 

AUG 1 04 

AUG/28 

SEP121 

SEP121 

SEP/28 

OCT128 

OCT13O 

NOV 1 08 

NOV1 30 

DEC102 

DEC126 

WEEK1DOY 

12/009 

171044 

19/060 

191060 

211076 

231084 

231084 

271118 

271118 

301137 

31 1 144 

34/168 

341168 

381192 

38/192 

411216 

451240 

48 / 264 

481264 

491271 

541301 

54/303 

551312 

58 1 334 

591386 

621360 

O-SR(S) 

l-SS(N) 

0 

0 

1 

0 

1 

0 

1 

0 

1 

0 

0 

0 

1 

0 

1 

0 

0 

0 

1 

0 

1 

1 

1 

1 

0 

0 

CAUSE 

SP 

E 

ADB(D) 

E 

ADB(D) 

E 

E 

E 

E 

ADB ( D) 

E 

E 

E 

E 

E 

E 

E 

E 

E 

SP 

E 

?(?) NO FICHE 

E 

E 

E 

E 

A-6 
ORBIT 

NUMBER 

6224 

6244 * 

6264 

6576* 

6696 

7085 

7239* 

7571 * 

7866 

7903* 

8278 

8340 

8567* 

8567* 

8897* 

9280 

9295 

9561* 

9892* 

9954 

10225* 

10887* 

MONTHIDAY 

JAN117 

JAN119 

JAN 1 20 

FEBI12 

FEB120 

MAR119 

MAR131 

APR 1 24 

MAY115 

MAY 1 18 

JUN I14 

JUN/l8 

JULIO5 

JULIO5 

JUL129 

AUG/25 

AUG 126 

SEP115 

OCT109 

OCTI13 

NOV 1 02 

DEC/BO 

1980 

WEEKIDOY 

651017 

651019 

66/020 

691043 

701051 

741079 

761091 

791115 

821136 

831139 

861 166 

871170 

891 187 

891187 

931211 

971238 

971239 

100/259 

1081283 

1041287 

1071307 

1131355 

O-SR(S) 

l-SS(N) 

0 

0 

1 

0 

1 

0 

0 

0 

0 

0 

1 

1 

1 

0 

1 

1 

0 

0 

0 

0 

1 

1 

CAUSE 

ADB(D) 

E 

ADB(D) 

E 

E 

ADB( D) 

E 

E 

AEB(D) 

E 

SP 

SP 

E 

E 

E 

SP 

SP 

E 

E 

SP 

E 

E 

NO MET DATA FOR THE FOLLOWING DAYS 

MARCH 5.6.7.8.9 

AUGUST 10.11 

DECEMBER 15.16 

A- 7 
1981 

ORBIT 

NUMBER 

11219* 

11549* 

11549* 

11882* 

11882* 

12214* 

12878* 

13210* 

13873* 

14205 * 

14264 

14291 

14536* 

14868 * 

15021 

15200 

15533* 

15658 

15788 

15863* 

14291 

MONTH 1 DAY 

JAN113 

FEB105 

FEB105 

MARIO1 

MAR 1 02 

MAR 126 

MAY113 

JUN 106 

JUL124 

AUG/l7 

AUG121 

AUG/23 

SEP110 

OCT 1 04 

OCT115 

OCT 128 

NOVI21 

NOV1 30 

DEC 109 

DEC115 

AUG123 

WEEK / DOY 

1171013 

1201036 

1201036 

1241060 

1241061 

1271085 

1341133 

137/157 

1441205 

1481229 

1481233 

1491235 

1511253 

1551277 

1561288 

1581301 

1611325 

1631334 

1641343 

1651349 

1491235 

O-SR(S) 

l-SS(N) 

0 

0 

1 

0 

1 

0 

0 

1 

1 

0 

1 

1 

0 

0 

1 

0 

0 

0 

0 

0 

0 

CAUSE 

E 

E 

E 

E 

E 

E 

E 

E 

E 

E 

SP 

SP 

E 

E 

SP 

E NO FICHE 

E 

ADB(D) 

s P+ ADB ( D 

E 

SP 

A-8 
1982 

ORBIT 

NUMBER 

16195* 

16195* 

16306 

16858* 

16858* 

17156 

17190* 

17190* 

17521* 

17853* 

18185* 

18185* 

18517* 

1851?* 

18595 

18678 

18848* 

18848* 

19110 

19118 

19512* 

19512* 

19649 

19844 * 

19844 * 

19852 

20553 

20629 

20643 

20679 

20684 

20753 

20796 

20804 

20851 

20892 

21001 

21016 

21065 

21011 

21123 

21137 

O-SR( S) 

MONTH /DAY WEEK1DOY l-SS(N) 

JAN 1 08 168 / 008 0 

JAN 1 08 1681008 1 

JAN116 1691016 0 

FEB125 1751056 0 

FEB125 1751056 1 

MAR118 178 1 077 0 

MAR121 1791080 0 

MAR121 1791080 1 

APR114 1821104 1 

MAY 1 08 185/128 1 

JUN101 1891152 0 

JUN/Ol 1891152 1 

JUN125 1921176 0 

JUN125 1921176 1 

JUN/ 30 1931181 0 

JULIO6 1941 187 0 

JUL/19 1961200 0 

JUL119 196 1 200 1 

AUG 1 07 198 1 219 1 

AUG / 07 1981219 0 

SEP105 2031248 0 

SEP105 2031248 1 

SEP115 2041258 1 

SEP129 2061272 0 

SEP129 2061272 1 

SEP129 2061272 1 

NOV1 19 2131323 0 

NOV / 24 2141328 0 

NOV125 2141329 1 

NOV/28 2151332 0 

NOV128 2151332 1 

DEC 1 03 2151337 1 

DEC106 2161340 1 

DEC 1 07 2161341 1 

DEC/10 2161344 1 

DEC/13 2171347 0 

DEC121 2181355 0 

DEC/22 2' 81'356 0 

DEC 1 26 2191360 1 

DEC/22 2--8/356 0 

DEC1 30 2191364 0 

DEC131 2191365 0 

NO MET DATA FOR THE FOLLOWING DAYS 

JANUARY 17,18 

JULY 13,14,27.28,29,30 

AUGUST 12.13 

A-9 

CAUSE 

E 

E 

SP+ ADB ( D ) 

E 

E 

E+ADB(D) 

E 

E 

E 

E 

E 

E 

E 

E 

ADB(D) 

ADB(D) 

E 

E 

?(D) 

SP+ ADB ( ? ) 

E 

E 

ADB(D) 

E 

E 

ADB(D) 

ADB(D) 

ADB(D) 

E 

ADB(D) 

E 

E 

SP 

ADB(D) 

?(?) 

ADB ( D) 

ADB(?) 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 
1983 

ORBIT 

NUMBER MONTH /DAY 

21178 JAN103 

21220 JAN 106 

21245 JAN 1 08 

21416 JAN 120 

21417 JAN120 

21834* FEB120 

21918 FEB / 26 

22436 APR1 04 

22444 APR105 

22757 APR 1 27 

22839 MAY/O3 

22860 MAY105 

23037 MAY118 

23052 MAY119 

23298 JUN105 

23369 JUN111 

23516 JUN121 

23723 JUL 1 06 

23831 JUL1 14 

238'76 JUL1 17 

23985 JUL125 

24292 AUG116 

24394 AUG 1 24 

24695 SEP115 

25060 OCT111 

25712 NOV 127 

25834 DEC 1 06 

261'76 DEC131 

WEEK1DOY 

2201003 

2201006 

2201008 

2221020 

2221020 

22'71051 

2271057 

2931094 

2331095 

236111'7 

23'71123 

237/ 125 

2391138 

2391139 

2421156 

2421162 

2441 172 

2461187 

2471195 

2481198 

2491206 

2521228 

2531236 

2561258 

2601284 

267 1 33 1 

2681340 

2'711365 

O-SR( S) 

l-SS(N) 

0 

0 

c 

[I 

3 

1 

0 

0 

1 

0 

1 

0 

1 

0 

0 

0 

1 

0 

1 

0 

0 

0 

1 

1 

1 

0 

0 

0 

CAUSE 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

E 

ADB(D) 

ADB(D) 

ADB ( D) 

ADB(D) 

E 

ADB(D) 

ADB(D) 

ADB(?) 

SP 

SP 

E+?(D) 

ADB(D) 

ADB(D) 

ADB(?) 

E 

SP+ ADB( D) 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

A-10 
1984 

ORBIT 

NUMBER 

26821 

27152 

27474 

27811 

28894 

30064 

30093 

30257 

30420 

30792 

MONTH /DAY 

FEB/15 

MAR110 

APR103 

APR/27 

JUL1 14 

OCT107 

OCT 1 09 

OCT/21 

NOV 1 02 

NOV/29 

WEEK1DOY 

278 I046 

2811070 

2851094 

288 11 18 

2991196 

3121281 

3121283 

3141295 

3151307 

3191334 

0-SR( S) 

l-SS(N) 

1 

1 

1 

1 

0 

1 

0 

0 

0 

1 

CAUSE 

E 

E 

E 

SP 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

E 

E 

A-11 
1985 

ORBIT 

NUMBER 

31684 

32021 

33210 

33491 

33760 

33925 

33981 

33995 

34051 

34078 

-34578 

MONTH / DAY 

FEB/O1 

FEB/25 

MAY / 23 

JUN1 12 

JULIO1 

JUL1 13 

JUL/ 17 

JUL/ 18 

JUL/22 

JUL/24 

AUG/29 

WEEK1DOY 

328 1032 

332 056 

3441148 

3471 163 

3501182 

3511194 

3521198 

3521 199 

3531203 

3531205 

358/241 

0-SR( S) 

l-SS(N) 

0 

0 

1 

1 

0 

0 

0 

0 

0 

0 

1 

CAUSE 

B 

E 

ADB(D) 

SP 

?(D) 

AbB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

ADB(D) 

FOLLOWING DAYS HAVE NO EVENTS 

JULY 2 

MAY 27,28,29,30,31 

A-12 

~- 
APPENDIX B 

SAGE PROFILE DATA USER’S GUIDE 

B-1 
B-2 
APPLICATIONS EXPLORER MISSION (AEM 2) 

STRATOSPHERIC AEROSOL AND GAS EXPERIMENT (SAGE) 

PROFILE DATA USER’S GUIDE 

B-3 
B-4 
PREFACE 

The SAGE Profile tapes have been revised as of August 1, 

1984 to incorporate zonal mean temperature corrections above 10 

mb described by Gelman et al. (1983). Temperature and density 

values have been changed to reflect these corrections as well as 

the values of NO2 extinction and the mixing ratios of NO2 and 03. 

In addition to allow for a comparison of this data set with 

other studies defined on a pressure coordinate system8 the 

revised profile tape contains a new array consisting of the 

pressure (mb) values associated with the extinction altitudes. 

B-5 
0 

APPLICATIONS EXPLORER MISSION (AEM-2) 

STRATOSPHERIC AEROSOL AND GAS EXPERIMENT (SAGE) 

DATA USER'S GUIDE 

Description of Experiment 

SAGE is a radiometer that measures the extinction of solar 

radiation traversing the Earth's limb during spacecraft sunrise 

and sunset in four wavelength bands centered at 0.385, 0.45, 

0.60, and 1.0 pm. The four-channel extinction data are combined 

with spacecraft ephemeris and a local atmospheric density profile 

and then numerically inverted to yield vertical profiles of 

aerosol extinction at 1.0 and 0.45 vm and O3 and NO2 

concentration. Details of the inversion process are discussed in 

"Inversions of Stratospheric Aerosol and Gaseous Constituents 

From Spacecraft Solar Extinction Data in the 0.38 - 1.0 pm 

Wavelength Region" by W. P. Chu and M. P. McCormick, Appl. Opt., 

- 18, 1404-1413, 1979. 

Spatial and Temporal Coverage 

SAGE was launched February 18, 1979, aboard the AEM-2 

spacecraft. The AEM-2 orbital geometry was such that SAGE 

sunrise and sunset observations were made every 96 minutes, i.e. 

every 24O longitude. 

months after launch, however, essentially limited data collection 

thereafter to sunsets only and eventually forced termination of 

all data collection after November 18, 1981. Latitude coverage 

Spacecraft power subsystem problems four 

B-6 
of the data, with some seasonal variation, extends from 72ON to 

72OS. (This latitude coverage complements the 640-80°N and 64OS8OoS coverage of the Nimbus 7/SAM I1 stratospheric aerosol sensor 

data, also archived at NSSDC.) 

Data Products 

1. SAGE radiance, spacecraft ephemeris, and NOAA correlative 

meteorological data are merged and recorded on Meteorological 

Ephemeris Radiance Data Archive Tapes (MERDAT) for archival 

at NSSDC. 

2. Processed SAGE data including aerosol, 03, and NO2 extinction 

profiles; O3 and NO2 number density profiles; 1.0 l.im 

extinction ratio and O3 and NO2 volume mixing ratio profiles; 

along with corresponding estimates of error at each altitude 

are recorded on PROFILE tapes for archival at NSSDC and the 

World Ozone Data Center (WODC). Each PROFILE contains a 

months time span of data. (A detailed PROFILE tape 

specification is enclosed.) 

Data Resolution and Accuracy 

The data have been validated by an extensive error analysis and 

comparisons with correlative observations. (See "SAGE Ground 

Truth Plan-Correlative Measurements for the Stratospheric Aerosol 

and Gas Experiment on the AEM-B Satellite," edited by P. B. 

Russell, NASA TM-80076, 1979.) The derived 1.0 pm aerosol 

extinction profiles have a vertical resolution of.1 km from cloud 

B-7 
tops to approximately 35 km with an error of < km -l (< 5 

percent at the peak): the derived 0.45 pm aerosol extinction 

profiles have a vertical resolution of 3 km with an error of 

approximately 20 percent: the derived NO2 concentration profiles 

have a vertical resolution of 3 km from 20-45 km with an error of 

approximately 30 percent at the peak: the derived 03 

concentration profiles have a vertical resolution of 1 km from 

the cloud tops to an altitude of approximately 40 km with < 10 

percent error at the peak. At altitudes where extinction values 

are < 2 x 

over a 5 km interval in height. The estimated errors of the 

derived products are calculated based on a vertical resolution of 

1 km. The horizontal resolution, i.e. integration along the 

viewing direction, is approximately 200 km. Additional 

information on the SAGE mission and the other NASA satellite 

observations of aerosols is available in "Satellite Studies of 

the Stratospheric Aerosol" by M. P. McCormick, et al., Bull. Am. 

Meteorol. SOC., - 60, 1038-1046, 1979 and "Stratospheric Aerosol 

and Gas Experiment (SAGE) Satellite End-of-Life Report" by M. 

Enciso and C. Kucera, NASA TM 83911, 1982. 

km", the O3 concentration profile is smoothed 

A description of the stratospheric meteorological data set which 

includes information about the various sources and methods of 

analysis of the data is given in "Mean Zonal Wind and Temperature 

Structure During the PMP-1 Winter Period" by M. E. Gelman et al. 

Adv. Space Res., - 2, 159-162, 1983. 

B-8 

-- 
SAGE PROFILES 

(AEROSOL, OZONE, AND NO2 EXTINCTION) 

USER'S GUIDE 

B-9 
PROFILES TAPE CHARACTERISTICS 

AND DATA ORGANIZATION 

This is on 9-track, 1600 CPI, unlabeled magnetic tape in fixed 

length 2200 CDC word (60 bit) binary records. Each record contains the data for one SAGE event. There is one file containing 

all available events for a period of one month. Missing events 

will not be padded. 

B-10 
PROF1 LES GROSS FORPIAT 

EVENT 1 

FIRST DAY OF MONTH 

I RG 

EVENT 2 

FIRST DAY.OF MONTH 

I RG 

I RG 

EVENT N 

LAST DAY OF MONTH 

EOF 

B-11 
PROFILES DETAIL DESCRIPTION 

The first 108 CDC words of each record will contain the following: 

EVENT DESCRIPTION AND METEOROLOGICAL DATA 

CDC 

WORD # 

1 

2 

3 

4 

5 

6 

7 

8 

9 

10 

11 

12 

13 

*14-32 

*33-51 

*52-70 

*71-89 

*90-108 

DESCRIPTION 

Satellite Code (AEM-B) 

Instrument (SAGE) 

Year 

Month 

Day 

Hour 

Minute 

Second 

Latitude 

Longitude 

Event Type (SUNRISE or SUN SET) 

No. Events in Day 

This Event No. in Day 

Temperature Deg. K or 9999. 

Temp. Error Deg. K or 999. 

Altitude in Meters or 99999. 

Density g/m3 or 9999. x lo5 

Density Error(Temp.Err./Temp.) or 999. 

CDC INTERNAL 

FORMAT 

A9 

A6 

I4 

I2 

I2 

I2 

12 

12 

A6 

A7 

A7 

12 

12 

Rea 1 

Real 

Real 

Real 

Real 

*The first 18 values correspond to fixed pressure levels in millibars: 

0.4. The 19th value is derived at the variable tropopause pressure. 

1000, 850, 700, 500, 400, 300, 250, 200, 150, 100, 70, 50, 30, 10, 5, 2, 1 

B-12 
PROFILES DETAIL DESCRIPTION (CONTINUED) 

Beginning 

CDC 

Word # 

109 

110 

111 

112 

113 

114 

115 

175 

235 

295 

355 

415 

475 

535 

595 

655 

715 

775 

83 5 

895 

955 

1015 

1075 

1135 

1195 

1255 

1315 

1375 

1435 

1495 

DATA PARAMETERS 

Length Description 

in CDC (All CDC Floating Point Words 

Words Unless Integer Specified) 

1 

1 

1 

1 

1 

1 

60* 

60* 

60* 

60*’ 

60*’ 

60* 

60* 

*t 60 

*t 

60 

60** 

60** 

60** 

60** 

60** 

60** 

Quality Code (0. to 1.) 1.0 micron extinction 

Quality Code (0. to 1.) .60 micron extinction 

Quality Code (0. to 1.) .45 micron extinction 

Quality Code (0. to 1.) .385 micron extinction 

Index #1* Integer 

Index #2** Integer 

Extinction altitudes (geometric) in km 

1.0 micron aerosol extinction km” 

.45 micron aerosol extinction km” 

.385 micron NO2 extinction km-’ 

1.0 micron aerosol extinction error km” 

.60 micron ozone extinction error km” 

.45 micron aerosol extinction error km” 

.385 micron NO2 extinction error km-’ 

1.0 micron transmission (0. to 1.) 

.60 micron transmission (0. to 1.) 

.45 micron transmission (0. to 1.) 

.385 micron transmission (0. to 1.) 

1.0 micron optical depth error 

.60 micron optical depth error 

.60 micron ozone extinction km- 1 

60** 

60** 

60** 

60** 

60** 

60** 

60* Ozone number density 

60* 

.45 micron optical depth error 

.385 micron optical depth error 

1.0 micron Rayleigh extinction km‘l 

.60 micron Rayleigh extinction km” 

.45 micron Rayleigh extinction km” 

.385 micron Rayleigh extinction km-’ 

Ozone number density error cmo3 

60*’ NO2 number density cm- 3 

B-13 
PROFILES DETAIL DESCRIPTION (CONTINUED) 

DATA PARAMETERS 

1555 60*' 

1615 60* 

1675 60* 

1735 60 * 

1795 

1855 

1915 

1975 

2035 

2095 

2100 

2105 

2110 

2111 

2112 

2113 

2173 

2193 

2194 

2195 

2199 

2200 

60* 

60* 

60* 

60*' 

60*+ 

5 

5 

5 

1 

1 

1 

60 * 

20 

1 

1 

4 

1 

1 

* 

** only elements 

only elements 

values below 10 km are 999. filled. t 

Address inquires or comments to: 

Aerosol Research Branch 

NASA Langley Research Center 

Mail Stop 475 

Hampton, VA 23665 

B-14 

NO2 number density error cm'3 

Aerosol number density (zero filled) 

Aerosol number density error (zero filled) 

1.0 micron extinction ratio 

(aerosol + molecular/molecular) 

1.0 micron extinction ratio error 

Ozone mixing ratio (v/v) 

Ozone mixing ratio error 

NO2 mixing ratio (v/v) 

NO2 mixing ratio error 

Tangent altitudes 210 to 50 km 

Corresponding latitudes 

Corresponding longitudes 

Event code INTEGER (0 = sunrise 1 = sunset) 

Event start time from Jan. 0 in days 

Spare 

Pressure (mb) corresponding to extinction altitude 

Zero fill 

Spare 

Revision date (e.g. 1984.08 = August 1984) 

Spares 

Total number of words in record (2200) INTEGER 

12 bit 1's complement add checksum with end-around 

carry INTEGER. 

1 - Index #1 (of 60) are defined 

1 - Index #2 (of 60) are defined (zero fill) 

. 
1. Report No. 2. Gomnmont kcdon No. 

NASA CR-178244 

4. Title and Subt+tle 

SAM I1 and SAGE Data Management and Processing 

M. T. Osborn and C. R. Trepte 

3. Rwipht's CIUlog No. 

5. Rm Dote 

February 1987 

6. Parforming Orpnirrtion Co& 

9. Perforrn~ng 0rO)n;zstion Name and Address 

ST Systems Corporation (STX) 

17 Research Drive 

Hampton, VA 23666 

12 Spcnsoring Avncy Name and Address 

National Aeronautics and Space Administration 

Washington, DC 20546 

15 Supptemen!rry Notes 

10. Work Unit No. 

11, Contract or Grant No. 

NAS1-17165 

13. Typl Of Repof! Md hid Covered 

Contractor Report 

14. Sponsoring Agency codr 

665-10-40-04 

Langley Technical Monitor: L. R. McMaster 

16 Abstract 

This report describes the data management and processing supplied by 

ST Systems Corporation (STX) for the SAM I1 and SAGE experiments under 

contract No. NAS1-17165 for the years 1983-1986. The report includes 

discussions of data validation, documentation, and scientific analysis, 

as well as the archival schedule met by the operational reduction of 

SAM I1 and SAGE data. Work under this contract resulted in the archival 

of the first seven years of SAM I1 data and all three years of SAGE 

data. A list of publications and presentations supported under this 

contract has also been included. 

7 Key Words (SugQestd by Author(rJJ 18. Dirtributton Statement 

SAM I1 

SAGE 

aerosols 

ozone 

I Unclassified - Unlimited I Subject Category 46 

nitrogen dioxide I 

9 !kcdrily Qarrif. (of this report) 

Unclassified Unclassified 62 A04 

20 kurity Classif (of this prgl) 21. No of Pw 22. Rice 

*-305 Fa sale by the Natlonal Technical Infamation Servlce. Springfield. Vlrginla 22161