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Greenhouse Effect Detection Experiment (GEDEX) CD-ROM Released by Lola M. Olsen and Archibald Warnock III 1992 has been designated as The International Space Year (ISY), the 500th anniversary of the discovery of America by Christopher Columbus and the 35th anniversary of the International Geophysical Year (IGY). The ISY effort is intended to stimulate significant contributions to worldwide scientific research and application activities under the theme "Mission to Planet Earth". The Space Agency Forum on the International Space Year (SAFISY) is responsible for coordinating these activities worldwide. In preparation for the ISY and in support of SAFISY, the Earth Science and Applications Division of NASA sponsored an initiative, the Greenhouse Effect Detection Experiment (GEDEX), for which a workshop was organized to bring together a core group of scientists to share their research and ideas on the subject of global climate change. Participants in this workshop, which was designated the GEDEX Atmospheric Temperature Workshop, met in Columbia, Maryland, in July of 1991 for the purpose of obtaining a measure of progress and to recommend 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 the discussions where concepts and hypotheses were exchanged. A document entitled, "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 discussions which took place during the workshop. One of the primary objectives of the workshop was to identify existing data (focusing on temperature) for the analysis of global climate change and to consolidate selected data sets onto CD-ROMs for distribution nationally and internationally to promote further research. With this focus, Dr. Schiffer requested that NASA's Climate Data System (NCDS) staff prepare for the acquisition, archiving, implementation, and documentation of data recommended for distribution. GEDEX Data Sets 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. 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. Some surface station data sets span more than 100 years. Most of the satellite-derived data sets cover only the most recent 12 years. Temporal resolution, for most data sets, is monthly. The first disk contains temperature, solar irradiance, cloud, and radiation budget data. The atmospheric constituent data are on the second disk. The data sets, thoroughly documented by standard detailed catalogs, are easily identified through the use of summaries which provide temporal coverage and resolution, spatial coverage and resolution, parameters, etc. 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 Nino/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 supplied 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 Earth Radiation Budget Experiment's (ERBE S4) combined 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 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. The CD-ROM Design The intention of the CD-ROM design was to deliver a standalone, operating system-independent package to the researcher: data for research, software tools to access the data, and complete documentation. The CD-ROM medium is ideally suited to this purpose. The large (approximately 650 megabytes) capacity, low cost and portable directory structure as enforced by the ISO-9660 specification, make it possible to inexpensively deliver large quantities of data to the end user for use on virtually every computer in use today. While ISO-9660 defines a platform-independent directory structure and file naming scheme for CD-ROMs, it imposes no requirements on the contents of the files. In order to make data accessible under any operating system, the data must be written in a way which is also independent of the host system. The Common Data Format (CDF) was selected for its advantages in representing the types of data structures found in various kinds of climate data. Gridded data maps naturally to the capabilities of CDF, and the format allows for easy storage of attribute information along with data. In addition, a software library for CDF data runs under several operating systems (Unix, VMS and MS-DOS) and provides for system-independent encoding of the data. This well-defined representation of the data ensures consistent access to the data. Software The access software provided on the disk allows the user to browse a table of contents to the disk and to view the summary and detailed information on the individual data sets. Additional software, developed by the CDF staff, provides browse and subsetting capabilities. The software runs with the same user interface under all three target operating systems. The overall user interface was designed to look and perform like the current NCDS online system. The interface in the current release is character-based but could easily be ported to standard windowing environments. GEDEX Research The hope is 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 these disks will serve as a test-bed for future CD-ROMs for EOS. Support for this effort from the Earth Science and Applications Division, NASA Headquarters was provided by Dr. Robert Schiffer. If you are interested in receiving a copy of the GEDEX CD-ROM, please contact the Goddard Distributed Active Archive Center (DAAC) User Support Office [NCDS has become part of the Goddard DAAC] by phone: (301) 286-2109, via Internet: NCDSUSO@xxxxxxxxxxxxxxxxxxxx or by mail: NCDS/Goddard Distributed Active Archive Center, Code 935, Goddard Space Flight Center, Greenbelt, Maryland 20771. An update to this CD-ROM disk set will be available for the United Nations Conference on Environment and Development which will be held in Brazil in June of 1992. ------------------------------------ GEDEX CD-ROM Disk Set Available at International Space Year Conference The second of four major conferences in celebration of the ISY was held in Munich, Germany at the Gasteig Convention Center the week of March 30th, 1992, with registered participants numbering close to 1500. Members of the Commission of the European Communities (CEC), the European Space Agency (ESA), and the German Space Agency (DARA) served as joint organizers. "Space in the Service of the Changing Earth" was the overall theme of the Conference. Concurrent symposia attracted outstanding participation in both a Central Symposium and the four Satellite Symposia. It was within the Central Symposium, designated the "Environment Observing and Climate Modeling through International Space Projects" that NASA's Contribution to the International Space Year was presented. A paper was presented entitled, "The Greenhouse Effect Detection Experiment (GEDEX) CD-ROM, A Collection of Data Sets for Global Change Research". Also, an exhibit in the conference area allowed interested participants to view the contents of the disks. A limited number of disks were available for distribution at the conference. Disks are being mailed to others requesting them. Thousands of additional interested observers were drawn to the Gasteig area of Munich by the "International Space Show, Planet Earth," held concurrently where four halls of space-related exhibits and a festival of space films organized by the European Association of Students of Aeronautics and Astronautics capitivated attendees.