NASA Technical Memorandum 110193 Compendium Of NASA Data Base For The Global Tropospheric Experiment's Pacific Exploratory Mission West-B (PEM West-B) G. L. Gregory and A. D. Scott, Jr. Langley Research Center, Hampton, Virginia October 1995 National Aeronautics and Space Administration Langley Research Center Hampton, Virginia 23681-0001 COMPENDIUM OF NASA DATA BASE FOR THE GLOBAL TROPOSPHERIC EXPERIMENT'S PACIFIC EXPLORATORY MISSION WEST-B (PEM WEST-B) By Gerald L. Gregory and A. Donald Scott, Jr. Langley Research Center SUMMARY The report provides a compendium of NASA aircraft data that are available from NASA's Global Tropospheric Experiment's (GTE) Pacific Exploratory Mission West-B (PEM West-B) conducted in February and March 1994. The NASA PEM West experiments (PEM West-A and -B) are a major component of the East Asia/North Pacific Regional Study (APARE), a project within the International Global Atmospheric Chemistry (IGAC) Program. PEM West flight experiments focused on the Pacific rim region and were primarily based at Guam, Hong Kong, and Japan. The broad objectives of the experiments were to study chemical processes and long-range transport associated with Asian continental outflow over the northwest Pacific Ocean and to document the magnitude of the human impact on the oceanic/marine atmosphere oven this region with an emphasis on ozone and sulfur chemistry (gas). PEM West-B, studied late-winter to early-spring meteorology during which Asian continental outflow was enhanced in comparison to outflow during the early-fall (September and October) time frame of the 1991 PEM West-A measurements. Results from PEM West-A and B are public domain (see Appendix B). PEM West-A data are summarized in NASA TM 109177 entitled "Compendium of NASA Data Base for the Global Tropospheric Experiment's Pacific Exploratory Mission West-A (published February 1995) and an in-press special issue of the Journal of Geophysical Research - Atmospheres. The format of this compendium utilizes data plots--time series and altitude profiles--of selective data acquired aboard the NASA/Ames DC-8 aircraft during PEM West-B. The purpose of this document is to provide a representation of aircraft data that are available in archived format via NASA Langley's Distributed Active Archive Center (DAAC). The data format is intended only to assist the reader in identifying data that are of interest. This compendium is for only the NASA aircraft data. The DAAC archived data bases include numerous supporting data including meteorological observations/products, photochemical modeling products, results from surface studies, satellite observations, and sondes releases. INTRODUCTION The goal of the NASA Tropospheric Chemistry Program is to develop an understanding of the chemical cycles that control the composition of the troposphere and to assess the susceptibility of the global atmosphere to chemical change. A major component of the NASA program is the Global Tropospheric Experiment (GTE), which consists of a series of field experiments designed to (1) evaluate the capability of instrument techniques to measure, under field conditions, the minute concentrations of key chemical species in the troposphere; and (2) systematically address tropospheric chemistry issues relevant to global change, through airborne sampling expeditions, coupled with modeling and laboratory studies. GTE is primarily an aircraft-based program supplemented by ground-based measurements. Satellite data also play important roles. Space Shuttle observations of tropospheric carbon monoxide distributions have been used to plan and direct the course of expeditions, for example, over tropical rain forests and for continental outflow into the tropical Atlantic Ocean. Landsat land-surface images have facilitated the extrapolation of regional Arctic-tundra measurements into global-scale conclusions. Total Ozone Measurements from Satellites (TOMS) have helped place GTE observed ozone distributions/budgets into a global perspective (temporal and spatial) and to guide intensive aircraft studies over the tropical Atlantic Ocean. Weather data returned by environmental satellites have guided flight planning for research flights. The Distributed Active Archive Center (DAAC) data include many of the satellite, surface, and meteorological products used to support GTE missions or analyses. The GTE airborne expeditions have focused on studies of the remote global atmosphere in order to provide well-documented baseline measurements of the unperturbed environment and to fully understand the chemical cycles underlying the natural environment. Table 1 and Figure 1 summarize GTE missions conducted through 1994 and the PEM Tropics mission scheduled for 1996. The GTE expeditions have been conducted in a diverse range of environments and with different scientific goals. The Chemical Instrument Test and Evaluation (CITE) series was designed to study our ability to measure key tropospheric gaseous species by exposing selected instrumentation to a wide range of measurement conditions. The Atmospheric Boundary Layer Experiments (ABLE) were designed to study the emission, chemical processes, and dynamics of the boundary layer, and have been conducted over ecosystems known to have significant influence on the global troposphere. The importance of long-range transport of natural and anthropogenic emissions on the global troposphere has been investigated in the Pacific Exploratory Missions (PEM) and the Transport and Atmospheric Chemistry Experiment in the Atlantic (TRACE-A). The GTE, managed through the Tropospheric Chemistry Program in the Mission to Planet Earth Office, NASA Headquarters, was initiated in the early 1980s. Implementation of the GTE Project is via a Project Office at the NASA Langley Research Center, Atmospheric Sciences Division. SYMBOLS AND UNITS ABLE Atmospheric Boundary Layer Experiment APARE East Asia/North pacific Regional Study CITE Chemical Instrument Test and Evaluation CO carbon monoxide CO2 carbon dioxide c2cl4 tetrachloroethylene CH3CCI3 methyl chloroform CH3OOH methyl peroxide CH3COOH acetic acid CH4 methane DAAC Distributed Active Archive Center deg. degree DMS dimethyl sulfide dp dew point temperature, degree Centigrade fine aerosol in the size range of ~0.01 to 1 micron diameter Ga.Inst. of Tech. Georgia Institute of Technology, Atlanta, Georgia GIT Georgia Institute of Technology, Atlanta, Georgia GTE Global Tropospheric Experiment H2O2 hydrogen peroxide HCOOH formic acid HNO3 nitric acid IGAC International Global Atmospheric Chemistry Program ITCZ Inter-Tropical Convergence zone LARC Langley Research Center large aerosol in the size range of 0.3 to 20 micron diameter N2O nitrous oxide NASA National Aeronautics and Space Administration NIES National Institute for Environmental Studies, Japan N2O nitric oxide NOy total odd nitrogen O3 ozone PAN peroxyacetyl nitrate PEM Pacific Exploratory Mission ppbv parts-per-billion, by volume ppmv parts-per-million, by volume PPN peroxypropionly nitrate pptv parts-per-trillion, by volume Rel. Humidity relative humidity, percent small aerosol in the size range of 0.1 to 3 micron diameter S2O sulfur dioxide T air temperature, degree Centigrade Theta potential temperature, degree Kelvin TOMS Total Ozone Measurements from Satellites TRACE-A Transport and Atmospheric -Chemistry Experiment in the Atlantic Univ.of CA, Irvine University of California at Irvine, California Univ.of NH University of New Hampshire, Durham, New Hampshire Univ. of RI University of Rhode Island, Narragansett, Rhode Island Univ. University PROGRAM AND DATA DESCRIPTIONS The National Aeronautics and Space Administration's Pacific Exploratory Mission West (PEM West) is a major component of the East Asia/North Pacific Regional study (APARE), a project within the International Global Atmospheric Chemistry (IGAC) program. The broad objectives of the PEM West/APARE initiative is to study chemical processes and long-range transport over the northwest Pacific Ocean, and to estimate the magnitude of the human impact (specifically Asian continental outflow) on the marine/oceanic atmosphere of the region. Specific objectives of PEM West are (1) to investigate the atmospheric chemistry of ozone (3) and its precursors over the northwest Pacific including examination of their natural budgets as well as the impact of anthropogenic sources; and (2) to investigate the atmospheric gaseous sulfur cycle over the northwest Pacific with emphasis on the relative importance and influence of continental versus marine sulfur sources. The Pacific Ocean is, perhaps, the only major region in the Northern Hemisphere that is "relatively" free from direct anthropogenic influences. In the remote regions of the northern Pacific and in most of the southern Pacific, it should be possible to study the biogeochemical cycles of carbon, nitrogen, ozone, sulfur, and aerosols in an environment which, from a global perspective, is least perturbed by anthropogenic activities. On the other hand, there is little doubt that long-range transport of air pollutants from Asia and, to a lesser extent, Europe and North America is beginning to have significant impact on the atmosphere over a large part of the Pacific. The results from the PEM West studies provide an extensive set of baseline data from which the anthropogenic impact of this region can be reliably assessed for decades to come. The overall experiment design for the PEM-West/APARE program encompassed two field studies positioned in time such that contrasting meteorological regimes in the northwestern Pacific could be studied. The first phase of the Pacific Exploratory Mission West, PEM West-A, was conducted over the Pacific Ocean off the coast of Asia during September and October, 1991. Significant characteristics of the lower troposphere airflow during this time of year includes periods during which the predominance of flow is from the mid-Pacific (marine) regions and periods in which the marine flow is modified/mixed with Asian continental outflow. Phase B of PEM West was conducted during February and March 1994, a period characterized by maximum outflow from the Asian continent with less predominance of flow from mid-Pacific marine regions. The centerpiece of PEM West-B was a series of 16 research flights with the instrumented NASA Ames DC-8. The aircraft operated from three staging areas: Anderson Air Force Base, Guam; Kai Tak International Airport, Hong Kong; and Yokota Air Force Base, Japan. Table 2 summarizes the flights, and Figure 2 shows the flight regions. Flights 6-9, 11-12, and 14-17 were site-intensive flights based from Guam, Hong Kong, and Japan, respectively. Survey/ferry flights included (a) flights 4-5 from NASA Ames to Guam (via Hawaii), (b) flight 10 from Guam to Hong Kong and (c) flights 18-19 from Japan to Ames (via Anchorage, Alaska). While the prime objective of the survey/ferry flights was to move the aircraft to a new base of operation, the flight plans were designed to provide as much information on the atmospheric processes and vertical structure of the atmosphere as possible. The intensive flights were designed to take advantage of the geographical location of the site and prevailing meteorological conditions in addressing science objectives. As a result of the location of the three intensive sites (staging areas), flights covered a latitude range of about 45 deg N to the Equator and sampled air with continental lifetimes of < 1 day (i.e., passed over the Asian continent within 1 day of sampling) to air which had been over the Pacific Ocean for >5 days. The majority of flights focused on studying the impact of aged, I to 3 days, Asian outflow on Pacific marine regions. Unique PEM west-B sampling events included (1) two flights south to the ITCZ and Equator (flights 6 and 9), (2) a flight which encircled the island of Taiwan (flight 12), (3) an upwind/downwind study of the island of Japan (flight 15), and (4) sampling of stratospherically influenced upper-tropospheric air in which ozone was elevated to several hundred ppbv (portions of flights 17 and 18). The core set of measurements aboard the aircraft focused on ozone and sulfur chemistry issues (gaseous). The aircraft data included a suite of chemical measurements which included ozone, nitric oxide (NO), total odd or "reactive" nitrogen gaseous species (NOy), sulfur dioxide, dimethyl sulfide, peroxyacetyl nitrate or PAN, peroxypropionly nitrate, methane, carbon monoxide, carbon dioxide, nonmethane hydrocarbons, fluorocarbons, acetic acid, formic acid, nitric acid, hydrogen and methyl peroxides. Two sets (Nagoya University and Georgia Institute of Technology) of NO and NO y data were measured aboard the aircraft. While the two NO data sets generally agreed, the NOy data sets did not agree in many cases. Laboratory and flight tests conducted by GIT (the results to be reported in a planned special issue of the Journal of physical Research - Atmospheres dealing with PEM West-B results) suggests that the NOy measurements obtained by the GIT instrument may lack specificity. Thus, for some flight/sampling/environmental conditions, differences in sampling procedures (e.g., inlet design/material, NOy converter parameters/conditions, sample flow rates, etc.) between the two instrumental approaches may account for much of the observed disagreement. Prior to publication of the planned special issue of the journal dealing with PEM WestB results, those interested in using PEM West-B NOy data are recommended to contact the respective NO y investigators. Aerosol measurements included filter collections for "elemental-type" analyses and optical measurements of number density in the classifications of fine (~0.01 to 1 Mu diameter), small (15 size bins covering the size range of ~0.1 - 3 Mu), and large (30 size bins covering the size range of ~0.3 - 20 Mu). Table 3 identifies investigators responsible for the measurements, and Figure 3 shows a schematic of the aircraft instrument plan. The aircraft platform as used in PEM West-B had a cruise speed at altitude of about 12 km/min and a maximum flight duration and ceiling of about 8-9 hours and 13 km, respectively. Survey flights were generally long-duration flights at high altitude (10 to 13 km) with (generally) at least one descent (spiral or ramp in addition to takeoff and landing) to about 150 to 300 m above sea level. Intensive flights combined numerous ramps, profiles, and level-flight legs to meet planned objectives. Generally, altitude profiles (spirals or ramps) were flown with ascent/descent rates of 150 to 300 m/min. The PEM West-B DAAC data archive includes (1) data taken aboard the NASA Ames DC-8 aircraft; (2) data measured at surface sites throughout the Pacific rim basin; (3) sondes released from multiple locations in support of the aircraft flights; (4) photochemical modeling products used in analyses of results; and (5) numerous meteorological, land-use, and satellite data products used in flight (field) planning and post-mission analyses. The data plots for the PEM West-B missions are given in Appendix A. For each flight, six pages of time series plots are provided: page 1 -- a pictorial diagram of the flight region and time series plots of altitude, temperature (T), dew point temperature (dp), relative humidity, and potential temperature (theta); page 2 -- ozone (O3), carbon monoxide (CO), carbon dioxide (CO2) methane, nitrous oxide (N2O), and benzene; page 3 -- nitric oxide (NO) as measured by Nagoya and GIT, total odd or "reactive" nitrogen gas species (NOy ) as measured by Nagoya and GIT, and nitric acid; page 4 -acetylene, ethane, propane, tetrachloroethylene (C2cl4), and methyl chloroform (CH3ccl3); and page 5 -- sulfur dioxide (SO2), dimethyl sulfide (DMS), ethylene, peroxyacetly nitrate (PAN), and acetone; page 6 -- hydrogen peroxide (H22)' methyl peroxide (CH3H), and number density for fine, small, and large aerosol. The species were selected to provide the reader with information on both the source characteristics and photochemical history of the air. Figure numbers correspond to flight numbers; e.g., Figure A4.2 represents page 2 of the plots for flight #4. Selected profile plots follow the time series plots as, e.g., Figure A4.7 is the first page of profile plots for flight 4. Profile plot sets include temperature, dew point temperature, ozone, carbon monoxide, and methane data plotted to the same altitude scale. One to three sets of profile plots are provided (format of two sets per page) for each flight. Table 4 summarizes the profiles selected. There are no figures with the prefix of A1, A2, or A3. Flights 1 to 3 were instrument checkout flights based at Ames and data were not archived. Data plots are in standardized format as discussed in Appendix A. The DAAC archive includes measurements aboard the DC-8 aircraft during PEM West-B which are not plotted in Appendix A. CONCLUDING REMARKS This compendium of data from NASA's Global Tropospheric Experiment's Pacific Exploratory Mission West-B provides only a representation of aircraft data that are available in archived format from NASA Langley's Distributed Active Archive Center (DAAC). The data presented here are intended only to serve as an overview of the PEM West-B data and provide some assistance to the reader in identifying data that are of interest and which may be obtained from Langley's DAAC archives This compendium covers only selected NASA DC-8 aircraft data. The archived data bases include other data measured on board the aircraft as well as numerous supporting data including meteorological observations/products, photochemical modeling products, surface station observations, satellite observations, and sondes releases. GTE-sponsored analyses/results from the PEM West-B expeditions have been submitted (September 1995) for a Special Issue of the Journal of Geophysical Research Atmospheres. Questions or information regarding the Langley DAAC archive should be directed to Langley DAAC User and Data Services, mail Stop 157B, NASA Langley Research Center, Hampton, Virginia 23681-0001. A brief description of the DAAC, log on procedures, and data bases is given as Appendix B. APPENDIX A: PEM WEST-B DATA PLOTS Plots are presented in a standardized format, and the data (unedited) are from the Langley DAAC archives Relative humidity and potential temperature are calculated from measurements made on the aircraft. In some cases (mostly for moist, boundary layer conditions) relative humidity may exceed 100% (not plotted) as dew point temperature exceeded air temperature by a few degrees (assumed to be the result of instrument measurement/calibration uncertainty). For time series plots, abscissa time scales for a given flight are identical. Ordinate scales (for a given parameter) may differ among flights and were selected to best represent all the data for the specie measured during the flight; thus, some data may be off-scale. As a result of the software used for the plots and the data archive use of codes (in place of valid data) for data taken (1) during instrument calibration, (2) when measurements were at "detection limit," and/or (3) when measurements were invalid, it is sometimes difficult to distinguish from the plots if data are off-scale or coded as invalid. For example, a symbol without an attached line may either mean that adjacent data are off-scale or have been coded as invalid. Inspection of the other plotted data often provides information which resolves the uncertainty. For profile plots, altitude scales are identical for all plots and the specie scales are those selected for the time series plots. In order to maintain the standardized format, plots for flights in which a specie data were not reported are plotted with the axes and a "No DATA" entry. Given below are the beginning page numbers for each flight's sequence of plots: Flight 4 - page 23 Flight 5 - page 31 Flight 6 - page 39 Flight 7 - page 47 Flight 8 - page 55 Flight 9 - page 63 Flight10 - page 71 Flight11 - page 79 Flight12 - page 87 Flight13 - page 95 Flight14 - page 103 Flight15 - page 111 Flight16 - page 119 Flight17 - page 127 Flight18 - page 135 Flight19 - page 143 TABLE 1. GTE Field Expeditions Expedition Date General Geographic Region Time of Year Atmospheric Boundary Layer Experiments ABLE-1 1984 Barbados,, French Guyana June ABLE-2A 1985 Amazon Basin August ABLE-2B 1987 Amazon Basin May ABLE-3A 1988 Alaska--Barrow, Bethel, Cold Bay July/August ABLE-3B 1990 Canada--Hudson Bay, Schefferville July/August Chemical Instrument Test and Evaluation Experiments CITE-1 1983 Hawaii November CITE-1 1984 Eastern North Pacific--off the California coast April CITE-2 1986 Western USA August CITE-3 1989 Western North Atlantic--Virginia coast August and Western South Atlantic--Brazil coast September Global Scale PhotochemistrylTransport Experiments PEM West-A 1991 Western Pacific Rim October TRACE-A 1992 Brazil, South Atlantic, southwest September Africa PEM West-B 1994 Western Pacific Rim Feb./March PEM-Tropics 1996 South tropical Pacific Ocean September TABLE 2. Summary of the Flights Conducted during the 1994 PEM West-B Expedition (All times are GMT) Mission Flight Date Departure Arrival Purpose Number Time Location Time Location 4 Feb. 7 2012 NASA Ames 0111 Hawaii survey & ferry 5 Feb. 8* 2012 Hawaii 0430 Guam survey & ferry 6 Feb. 11 2100 Guam 0438 Guam ITCZ, southern hemispheric air 7 Feb. 13 2313 Guam 0653 Guam marine frontal system 8 Feb. 17 2258 Guam 0750 Guam marine frontal system 9 Feb. 19 0253 Guam 0840 Guam ITCZ, southern hemispheric air 10 Feb. 21 0058 Guam 0922 Hong Kong survey & ferry, ITCZ 11 Feb. 25 0152 Hong Kong 0926 Hong Kong Asian outflow 12 Feb. 27 0145 Hong Kong 0947 Hong Kong Asian outflow & Taiwan flyby 13 March 1 0201 Hong Kong 0900 Yokota, Japan survey & ferry 14 March 4 0335 Yokota, Japan 1005 Yokota, Japan Asian outflow 15 March 5 2329 Yokota, Japan 0653 Yokota, Japan upwind/downwind Island of Japan 16 March 7 0105 Yokota, Japan 0842 Yokota, Japan Asian outflow 17 March 11 0010 Yokota, Japan 0710 Yokota, Japan Asian outflow 18 March 13* 0012 Yokota, Japan 0738 Anchorage,Alaska survey & ferry 19 March 14 1709 Anchorage, Alaska 2322 NASA Ames survey & ferry * Crossed International date line TABLE 3. Principal Investigators and Institutions Participating in PEM West-B Investigator Institution Investigation/Measurement Bruce Anderson NASA Langley Research Center carbon dioxide, fine aerosol Alan Bandy Drexel University S02 & dimethyl sulfide Donald Thornton John Barrick NASA Langley Research Center meteorological/position data John Bradshaw Georgia Institute of Technology nitric oxide, total oxides of nitrogen Edward Browell NASA Langley Research Center ozone & aerosol profiles (remote sensor) Gerald Gregory NASA Langley Research Center ozone (in situ) Brian Heikes University of Rhode Island H202, CH300H Yutaka Kondo Nagoya University, Japan nitric oxide, total oxides of nitrogen Rudolph Pueschel NASA Ames Research Center small and large aerosol Sherry Rowland University of California, Irvine nonmethane hydrocarbons Donald Blake Glen Sachse NASA/Langley Research Center carbon monoxide, methane, nitrous oxide Hanwant Singh NASA Ames Research Center PAN, PPN C2Cl4, acetone, acetyaldehyde Robert Talbot University of New Hampshire HNO3, HCOOH, CHICOOH, aerosol composition (elemental) TABLE 4. PEM West-B Profiles Flight Date Time Latitude,Deg N Longitude,Deg E 4 February 7 2030 37.3 -122.9 4 February 8 0100 21.4 -157.7 5 February 8 2030 21.4 -158.8 5 February 9 0415 13.7 145.3 6 February 12 0030 - 9.6 152.2 6 February 12 0130 - 5.3 149.9 7 February 13 2330 14.8 145.3 7 February 14 0315 20.9 145.0 8 February 18 0115 29.2 145.2 8 February 18 0730 13.9 145.3 9 February 19 0500 0.9 146.3 9 February 19 0830 12.6 145.0 10 February 21 0500 5.8 119.4 10 February 21 0715 15.9 117.3 10 February 21 0900 21.9 114.2 11 February 25 0200 21.5 115.1 11 February 25, 0430 8.8 117.2 12 February 27 0715 22.6 119.6 12 February 27 0930 22,2 114.9 13 March 1 0215 21.9 115.2 13 March 1 0845 34.6 139.6 Times are GMT TABLE 4. Profiles continued. Flight Date Time Latitude,Deg N Longitude,Deg E 14 March 4 0345 34.8 139.3 14 March4 0800 25.9 138.9 15 March 6 0300 40.3 138.6 15 March 6 0600 36.2 144.7 16 March 7 0300 30.6 155.0 16 March 7 0425 27.9 163.9 17 March 11 0030 37.0 139.3 17 March 11 0700 36.1 139.7 18 March 13 0300 47.1 164.0 18 March 13 0515 53.8 -173.2 18 March 13 0730 60.9 -150.8 19 March 14 1730 60.4 -150.6 19 March 14 2045 44.2 -140.4 19 March 14 2145 39.7 -134.1 Times are GMT APPENDIX B: LANGLEY DAAC DATA ARCHIVE System Description The Langley Distributed Active Archive Center (DAAC), located at the NASA Langley Research Center in Hampton, Virginia, is responsible for archiving and distributing NASA science data in the areas of radiation budget, clouds, aerosols, and tropospheric chemistry. This DAAC will also archive some of the data sets which result from the EOS program and other elements of Mission to Planet Earth. The DAAC has developed an on-line computer system which allows the user to log on, search through the DAAC's data inventory, choose the desired data sets, and place an order. Data may be received either electronically (via FTP) or on media such as 4mm tape, 8mm tape, or CD-ROM (prepackaged data sets only). Log On Procedures 1. Users with an X-Windows terminal (e.g., motif) or a Sun open Windows display system with access to Internet, may log onto the system by entering: xhost + eosdis.larc.nasa.gov (or: xhost + 192.107.191.17) telnet eosdis larc.nasa.gov login name: ims password: larcims At the prompts, enter x for the X-Windows interface and then your-display name (name of your workstation followed by ":0" or Internet address followed by ":0"). 2. Users with access to NCSA Mosaic can use the following URL address: http://eosdis.larc.nasa.gov/ 3. Users without access to a terminal with an X-Windows display system but who have access to Internet may log onto the system by entering: telnet eosdis.larc.nasa.gov login name: ims password: larcims At the prompt, enter c for the character interface and then press return. 4. Users who cannot access the system or who have any questions concerning the Langley DAAC may contact: Langley DAAC User and Data Services Mail Stop 157B NASA Langley Research Center Hampton, VA 23681-0001 Phone: (804) 864-8656 FAX: (804) 864-8807 email: larc@eos.nasa.gov DAAC Data Bases 1. ERBE (Earth Radiation Budget Experiment)--Data were collected from three satellites (ERBS, NOAA-9, NOAA-10) carrying two ERBE instruments (scanner, nonscanner). The objective is to measure global albedo, fluxes, and solar incidence. 2. ISCCP (International Satellite Cloud Climatology Project)--ISCCP focuses on the study of the distribution and variation of cloud radiative properties. The objective is to improve the understanding and modeling of the effects of clouds on climate and also to elucidate the role of clouds in the radiation balance and improve our knowledge of the long-term global hydrologic cycle. 3. SAGE (Stratospheric Aerosol and Gas Experiment)--SAGE I gathered data concerning the spatial distribution of stratospheric aerosols, ozone, and nitrogen dioxide on a global scale. The goals of SAGE II are to determine the spatial distributions of stratospheric aerosols, ozone, nitrogen dioxide, water vapor, and cloud occurrence by mapping vertical profiles and calculating monthly averages of each. 4. SRB (Surface Radiation Budget)--The SRB data sets were calculated using inputs from ISCCP and ERBE data. They are designed to give global daily and monthly averages of the albedo, irradiance, cloud properties, and meteorology. 5. FIRE (First ISCCP Regional Experiment)--This series of experiments includes aircraft, satellite, and surface-based measurements of cirrus and marine stratocumulus cloud parameters. The purpose of this program is to validate and improve ISCCP data products and cloud/radiation parameterizations used in general circulation models (GCMs). 6. GTE (Global Tropospheric Experiment)--Data were collected primarily from aircraft and ground-based instruments from a variety of areas such as the Amazon Rain Forest and the northern tundra and boreal forest. Many parameters were measured including O3, CH4, PAN, CO, NO, NO2, CO2, and aerosols. 7. MAPS (Measurement of Air Pollution from Satellites)--Data were collected during Space Shuttle flights in 1981, 1984, and 1994. The main pollutant measured was carbon monoxide (CO). 8. SAM II (Stratospheric Aerosol Measurement)--This instrument was flown on board the Nimbus-7 satellite and consisted of a one-spectral channel Sun Photometer, centered at 1.0 um, which viewed a small portion of the Sun through the Earth's atmosphere during spacecraft sunrise and sunset. The data obtained from this instrument were used to determine the vertical distribution of stratospheric aerosols in the polar regions of both hemispheres.