Greenhouse Effect Detection Experiment (GEDEX) Selected Data Sets

Lola M. Olsen
Archibald Warnock III

Prepared as a NASA contribution to The Space Agency Forum on The International Space Year 1992
NASA Climate Data System Staff
Goddard Distributed Active Archive Center
NASA --- Goddard Space Flight Center
Greenbelt, Maryland 20771

In the LDEO WWW Data Library, some of these data are available as a dataset, including an interative viewer and downloadable data files.


In preparation for the International Space Year (ISY), the Greenhouse Effect Detection Experiment (GEDEX), a NASA Earth Science and Applications Division-sponsored initiative in support of the Space Agency Forum on the International Space Year (SAFISY), organized a workshop to bring together a core group of scientists to share their research and ideas in the area of global climate change. Participants in this workshop, which was designated GEDEX Atmospheric Temperature Workshop met in Columbia, Maryland, in July of 1991 for the purpose of obtaining a measure of progress and recommending actions required to better understand the global atmospheric temperature record and its relationship with climate forcings and feedbacks. Dr. Robert A. Schiffer and Dr. Sushel Unninayar organized and led the discussions where concepts and hypotheses were exchanged. The document, The Detection of Climate Change Due To The Enhanced Greenhouse Effect: A Synthesis of Findings Based on the GEDEX Atmospheric Temperature Workshop, issued by NASA Headquarters in February 1992 summarizes the ideas and discussions which took place during the workshop.

One of the primary objectives of the workshop was to assemble and document existing data (focusing on temperature) for the analysis of global climate change and to consolidate these selected data sets onto CD-ROMs for distribution nationally and internationally to promote further research. With climate as the focus, Dr. Schiffer requested that NASA's Climate Data System (NCDS) staff participate and prepare for the acquisition, archiving, implementation, and documentation of data recommended for distribution. NCDS has been designated as the core system for the Goddard Space Flight Center's Distributed Active Archive Center (DAAC) of the Earth Observing System Data and Information System (EOSDIS), and in this role will continue to update GEDEX-relevant data sets. All data will remain in the Goddard DAAC (NCDS) and will be updated whenever new releases are made available. Subsequent updates will therefore be made available in an ongoing manner to the climate user community. More than 60 data sets were identified by workshop participants for inclusion, yielding nearly 1 gigabyte of data for this first 2-disk set of CD-ROMs.

Immediately following the workshop, staff members began gathering and implementing the designated data to make it available to the climate user community through the online interactive data system, as well as preparing the data for publication on CD-ROM. NCDS staff members also translated data into a standard format (the Common Data Format [CDF]) to allow for the use of a single set of software tools to access the data on disks.

Most participants contributed data and helped in the preparation of the standard documentation for each data set slated for CD-ROM. Each data set was verified by the NCDS staff after it was transformed into CDF. Iterations of the detailed documentation and extensive verification with data producers ensure that the data are reproduced as received from data producers. The data producers cooperated fully with this essential effort.

The data sets include surface, upper air, and/or satellite-derived measurements of temperature, solar irradiance, clouds, greenhouse gases, fluxes, albedo, aerosols, ozone, and water vapor, along with Southern Oscillation Indices and Quasi-Biennial Oscillation statistics. Many of the data sets provide global coverage. The spatial resolutions vary from zonal to 2.5 degree grids. Temporal coverage also varies. Some surface station data sets cover more than 100 years, while most of the satellite-derived data sets cover only the most recent 12 years. Temporal resolution, for most data sets, is monthly.

The data sets, thoroughly documented through standard detailed catalogs, are easily identified through the use of summaries providing temporal coverage and resolution, spatial coverage and resolution, parameters, etc.

GEDEX Data Sets

%Within the workshop environment, participants recommended data sets that During the workshop, participants recommended data sets that they considered directly or indirectly relevant to the study of the Greenhouse Effect. One session at the workshop was devoted to identifying data sets for the CD-ROMs, including recommended temporal and spatial resolutions. Although the focus of the first GEDEX workshop was on temperature, other parameters such as solar irradiance, atmospheric constituents, cloud, and radiation budget data which affect the temperature record were considered essential components of these disks. The data on the disks have been categorized by these parameters for summary here. The temperature, solar irradiance, cloud, and radiation budget data can be found on Disk 1. The atmospheric constituent data are contained on Disk 2. Satellite-based data overlap these categories but are also designated separately. Additionally, the documentation of data sets is discussed briefly.

Disk 1 --- Temperature, Radiation and Cloud Data

Temperature --- Surface

The basic surface station temperature data set from NCDC/NCAR contains monthly temperature and precipitation values and is subdivided by continent. A few records date from as early as 1738, and modern station data extend through 1989. Other surface temperature anomaly data sets containing monthly gridded values were provided by Philip Jones, University of East Anglia Climate Research Unit, and by James Hansen, Goddard Institute for Space Studies (GISS). Zonal and station temperature data are included from the State Hydrologic Institute's (Russia) Konstantin Vinnikov. These data sets extend over 100 years of record. Gridded 2.5 degree monthly sea surface temperature data and anomalies as calculated by Richard Reynolds from NOAA's Climate Analysis Center also reside on this disk. These SST values are from AVHRR sensors on NOAA polar orbiters and are blended with ship and buoy data. Investigating the effect of the El Niño/Southern Oscillation (ENSO) on the temperature anomaly record, may be done with the data set provided by the University of East Anglia's Climate Research Unit containing the Southern Oscillation Index calculations, along with the Tahiti and Darwin mean sea level pressures from which they are derived.

Temperature --- Upper Air

NCDC/NCAR contributed comprehensive monthly station rawinsonde data. Both temperature and humidity profiles are included in this data set. Another upper air temperature data set was produced by James Angell, NOAA ARL. It contains seasonal zonal temperature deviations from rawinsonde data around the world. Angell also provided Quasi-Biennial Oscillation temperature and zonal wind data at 50, 30, and 10 mb. Marshall Space Flight Center's Roy Spencer provided more than 12 years of mid-tropospheric temperature and anomaly data from the TIROS Operational Vertical Sounder Microwave Sounding Unit (TOVS-MSU), flown on NOAA polar orbiters. Stratospheric temperature data were provided by Harry van Loon and Karen Labitzke through NCAR. Although these data are only available for the northern hemisphere, they provide a valuable monthly zonal product for the years 1957 to 1991. In addition, profiles of meteorological data from NMC were provided at 1 km intervals for the Stratospheric Aerosol and Gas Experiment (SAGE II) time period.

Solar Irradiance and Transmission

Solar transmission and surface-measured irradiance data were sent by Ellsworth Dutton, NOAA Climate Monitoring and Diagnostics Laboratory (CMDL). The daily solar transmission indices from the Mauna Loa Observatory begin in 1958 and continue through 1990. The hourly solar irradiance data make up a rare collection of solar data collected at the surface from 1976 to 1989 at selected sites. NASA Goddard Space Flight Center's Lee Kyle provided solar irradiance data from the Nimbus-7 Earth Radiation Budget (ERB) instrument, and Langley Research Center's Robert Lee, offered the solar irradiance data from NOAA-9, NOAA-10, and ERBS. Richard Willson of JPL has collaborated with the NCDS staff over the years in making 9 years of solar irradiance data from the Solar Maximum Mission's ACRIM sensor available to users online. The Dominion Radio Astrophysical Observatory (DRAO) (formerly Ottawa) 2800 MHz radio flux data from 1947 to the present are also available on the disk with observed, absolute, and adjusted variables.

Radiation Budget and Clouds

Bruce Barkstrom of Langley Research Center provided the combined Earth Radiation Budget Experiment's (ERBE S4) satellite gridded products, including the scanner data at 2.5 degree resolution and the wide-field-of-view monthly averages. William Rossow, NASA GISS, suggested and subsequently provided a comprehensive subset of the International Satellite Cloud Climatology Project's (ISCCP) monthly cloud products at 2.5 degree resolution. He also assisted in the review and verification of those data. Goddard's Lee Kyle worked closely with the staff in the validation of data on the disk from the Earth Radiation Budget instrument on board Nimbus-7. Data from the wide-field-of-view sensor span the period 1978 to 1987 and are monthly in temporal resolution and approximately 4.5 by 5 degrees in spatial resolution. Goddard's Joel Susskind also worked closely with the NCDS staff, making subsets of his cloud and radiation data available for the disk. His data are derived from NOAA Polar Orbiting satellites using TOVS-HIRS and TOVS-MSU sensors.

Disk 2 --- Atmospheric Constituents

Atmospheric Constituents

The Carbon Dioxide Information Analysis Center (CDIAC), Department of Energy, is the source for the ``TRENDS '90, A Compendium of Data on Global Change,'' providing carbon dioxide and methane values spanning the geological record (through ice core techniques) and more recent values collected by NOAA from flask sampling and continuous monitoring techniques. NOAA ARL's James Angell also contributed seasonal layer ozone data from Umkehr sounding and ozonesonde from 1957 to 1990, and total ozone from Dobson spectrophotometers for the period 1967 to 1989. Patrick McCormick's colleagues at NASA's Langley Research Center worked closely with our staff in providing ozone, nitrogen dioxide, and aerosol data from the Atmospheric Explorer Mission's SAGE I instrument, and aerosol, ozone, water vapor, and nitrogen dioxide data from the Earth Radiation Budget Satellite's (ERBS) SAGE II instrument beginning with data from the November 1984 launch through 1991.

Satellite-based Data

The satellite-based data sets are those from Solar Maximum Mission's ACRIM instrument, the Nimbus-7 Earth Radiation Budget instrument, the Atmospheric Explorer Mission's SAGE I sensor, the Earth Radiation Budget Satellite's SAGE II sensor, the NOAA polar orbiter TOVS-HIRS and TOVS-MSU instrument, the Earth Radiation Budget Experiment (NOAA-9, NOAA-10, and ERBS sensors), and the International Satellite Cloud Climatology Project's AVHRR, MIR and VAS sensors on NOAA Polar Orbiters, GOES, Meteosat, and GMS satellites.


Each data set is accompanied by a detailed catalog in a standard format (in the subdirectory DETAILED) and by a short summary file (in the subdirectory SUMMARY). In addition, the DETAILED subdirectory also contains descriptions of satellite sensors and the products from which the geophysical parameters on this disk are derived. Among these are AVHRR, TOVS, VAS, VISSR, ERB, ERBE, SAGE I, and SAGE II.

GEDEX Research

It is hoped that through this consolidation and documentation of existing data sets, ambiguities and uncertainties associated with climate change and greenhouse gas effect will be further explored by more scientists. It is also hoped that researchers will continue to review the relationships between temperature change and plausible cause-effect factors, and that this disk will serve as a test-bed for future CD-ROMs for EOS.


The creation and distribution of the GEDEX CD-ROM disk set was an effort that pressed the entire NCDS staff into service to meet the standards adopted at the outset. Bruce Vollmer, NCDS task leader, coordinated the effort for Hughes STX. Ke Jun Sun coaxed CDFs from many nebulously formatted, vaguely documented, but vitally important data sets. Configuration management was expertly handled by systems architect John Vanderpool, who also created the package of software for users of this disk and helped in data set implementation. The integrity of the data base, now fully normalized by data base designer Hank Griffioen, permitted the assimilation of designated data holdings for this CD-ROM. Staff members Jim Closs and Frank Corprew balanced their workload in the user support office while managing to implement data sets and help in data documentation. Overseeing the archiving and inventory of data was Joe Brown, aided by Frances Bergman. Rick Amick fine-tuned the artwork, and helped with editing. Sue Sorlie rendered important assistance in data verification. Pat Hrubiak, designed the logo for this CD-ROM, contributing in the areas of quality control and catalog updates as well.

In addition to the full cooperation from the data set producers already mentioned, valuable assistance was also offered by Alison Walker and Helene Wilson from GISS, Mike Rowland and Er-won Chiou from Langley Research Center, Lena Iredell from Goddard Space Flight Center, and Pavel Groisman from the State Hydrological Institute (presently at NCDC). Michael J. Martin of the Jet Propulsion Laboratory provided valuable assistance by producing a preliminary version of this disk for testing.

Support for this effort from the Earth Science and Applications Division, NASA Headquarters was provided by Dr. Robert Schiffer. Dr. Sushel Unninayar (NASA Headquarters/University Corporation for Atmospheric Research) provided important suggestions and encouragement throughout.

Further information on GEDEX can be obtained by contacting:

Dr. Robert A. Schiffer
Chief, Climate and Hydrological Systems Branch
Earth Science and Applications Division
NASA Headquarters, Code SED
Washington, DC 20546

tel: (202) 453-1680
fax: (202) 755-5032

Further information on the CD-ROM can be obtained by contacting:

Lola M. Olsen
Project Manager, NASA's Climate Data System
Data Management Systems Facility
Goddard Space Flight Center
Greenbelt, MD 20771

tel: (301) 286-9760
fax: (301) 286-3221