Organization: National Aeronautics and Space Administration (NASA)

Research Title: Total Ozone Mapping Spectrometer Program (TOMS)

Funding Level (millions of dollars):

FY94 17.0
FY95 18.6
FY96 11.8

Committee on Environment and Natural Resources (CENR) Component:
(a) Subcommittee: Global Change Research Subcommittee (100%) Task Group on Observations and Data Management
(b) Environmental Issue: Stratospheric ozone, Tropospheric ozone Surface Ultraviolet Radiation
(c) Research Activity: System structure and function: Observations (100%)

Organizational Components:
Mail Code YS
Washington, DC 20546

Point of Contact:
Jack A. Kaye
Phone: 202-358-0757
Fax: 202-358-2770

Research Goals:
Build, integrate, launch for space flight modified version of the Total Ozone Mapping Spectrometer (TOMS) instrument to measure total ozone from space; process and analyze data from operating instruments.

Research Description:
The TOMS instrument is a six channel ultraviolet radiation remote sensing instrument using the Backscatter Ultraviolet (BUV) technique to measure total ozone amounts from space. By virtue of cross-track scanning, it provides complete daily maps of total ozone distribution over sunlit regions of the Earth. TOMS measurements go back to October, 1978 with the launch of the first TOMS instrument aboard NASA's Nimbus 7 satellite. This instrument operated until May, 1993. A second TOMS instrument was launched aboard a Russian Meteor-3 spacecraft in August, 1991 and continues to operate at this writing. Future launches of TOMS instruments are planned for the following schedule:

Fall 1994 - launch aboard Earth Probe satellite using Pegasus XL vehicle

Winter 1996 - launch aboard Japanese ADEOS spacecraft

Mid- 1998 - launch aboard a Russian Meteor-3M spacecraft Each of these future TOMS instruments is planned to fly in a polar, sun- synchronous orbit, which is optimal for measurements of global ozone using the BUV technique.

Program Interfaces:
The major interfaces of the TOMS program are to the stratospherically oriented programs within NASA, including the Atmospheric Chemistry Modeling and Analysis Program (ACMAP) and the Upper Atmosphere Research Program (UARP). There is a close relationship between the TOMS program and the Solar Backscatter Ultraviolet (SBUV/2) program conducted by NOAA and NASA through the flight of SBUV/2 instruments aboard NOAA's polar orbiting meteorological satellites (SBUV/2 also measures total ozone using the BUV technique but does not have cross-track scanning capability to provide full surface mapping). The TOMS program also interacts closely with NASA's Shuttle Solar Backscatter Ultraviolet (SSBUV) Program, located within the Payloads and Instrument Development Program within MTPE. The TOMS program also has a close relationship with the Global Ozone Monitoring Experiment (GOME) instrument being prepared for launch by the European Space Agency. Linkage to the broader international scientific community is accomplished mainly through the Stratospheric Processes and their Role in Climate (SPARC) subgroup of the World Climate Research Program (WCRP) as well as use of TOMS data in externally-sponsored international assessments, such as the World Meteorological Organization/ United Nations Environment Programme (WMO/UNEP) ozone assessment. NASA and FAA have recently signed a memorandum of agreement to facilitate FAA's use of real-time TOMS data in a test mode to determine its usefulness in aircraft routing for both hazard avoidance and improved efficiency.

Program Milestones:
FY 1994: complete development of TOMS version 7 algorithm, obtain accurate calibration parameters for Meteor 3 TOMS instrument; FY1995: Launch EP TOMS (assuming launch vehicle readiness) and begin data production, reprocess Nimbus 7 TOMS data with version 7 algorithm; FY96: ADEOS TOMS launch

Policy Payoffs:
Continued accurate global monitoring of global total ozone distributions which can be used in international assessments and in determination of atmospheric response to trace gas forcing.