Summary of the Total Ozone Mapping Spectrometer (TOMS) Data
The Total Ozone Mapping Spectrometer (TOMS) data represent the primary long-term, continuous record of satellite-based observations available for use in monitoring global and regional trends in total ozone over the past 25 years. TOMS also provides measurements of tropospheric aerosols, volcanic SO2, ultraviolet irradiance, erythemal UV exposure, and effective reflectivity from the Earth's surface and clouds. The data are produced by the Laboratory for Atmospheres at NASA's Goddard Space Flight Center.
Four TOMS instruments have been successfully flown in orbit – aboard the Nimbus-7 (Nov. 1978 - May 1993), Meteor-3 (Aug. 1991 - Dec. 1994), Earth Probe (July 1996 - current), and ADEOS (Sep. 1996 - June 1997) satellites. Version 8 TOMS data products are available from the Goddard Earth Sciences Distributed Information and Services Center (GES DISC). These include level 3 gridded data (1.0° x 1.25°) as well as level 2 instrument resolution data (between 50x50 km and 26x26 km pixel at nadir). At this time, the data are from the Nimbus-7 and Earth Probe TOMS instruments.
WARNING: EP TOMS started experiencing calibration problems a few years after launch. For data beginning in year 2000, the calibration had been stabilized relative to NOAA-16 SBUV/2 in the equatorial zone. Because of continuing changes in the optical properties of the front scan mirror, the data were showing a latitude-dependent error that could not be corrected by a simple calibration correction. The calibration appeared to be stable near the equator. But by 50° latitude, there was a -2% to -4% error in TOMS, a bit larger in the northern hemisphere than in the southern hemisphere. Because of this error, data since 2002 had been recommended NOT be used for trend analysis.
The principle investigator for TOMS is Dr. Richard McPeters (Richard.D.McPeters@nasa.gov). For more information about TOMS, please see the official TOMS web site (http://ozoneaq.gsfc.nasa.gov).
The Version-8 Algorithm Theoretical Basis Document (ATBD)is also available from the TOMS site:
Data access is available through:
- Giovanni (http://giovanni.gsfc.nasa.gov) a Web-based data visualization and analysis system
Related Data Documents:
For further assistance, please do not hesitate to contact us.