Total Ozone Mapping Spectrometer

Total Ozone Mapping Spectrometer
Name	Total Ozone Mapping Spectrometer
Acronym	TOMS
Operator	National Aeronautics and Space Administration; NASA Goddard Space Flight Center
Country	United States
Type	Satellite-mounted spectrometer
Launched	1978; 1991; 1996; 2004
Status	Decommissioned (successors operational)

Total Ozone Mapping Spectrometer The Total Ozone Mapping Spectrometer was a series of satellite-mounted ultraviolet spectrometers developed to map global column ozone and monitor stratospheric composition. Designed and operated by teams at NASA Goddard Space Flight Center with partnerships involving Orbital Sciences Corporation, Ball Aerospace, Royal Netherlands Meteorological Institute, National Oceanic and Atmospheric Administration, and research groups at University of Colorado Boulder, it provided continuous records that informed policy decisions by United Nations Environment Programme, World Meteorological Organization, and national agencies. Instruments flew on missions connected with programs such as Nimbus 7, the Upper Atmosphere Research Satellite, and the Earth Probe program, contributing to assessments like the Montreal Protocol compliance reviews and reports used by the Intergovernmental Panel on Climate Change.

Overview

TOMS was engineered to measure total column ozone by detecting backscattered solar ultraviolet radiation across discrete wavelength bands, enabling daily near-global coverage that supported studies at institutions such as Jet Propulsion Laboratory, National Center for Atmospheric Research, Scripps Institution of Oceanography, Columbia University, and Massachusetts Institute of Technology. The program intersected operational meteorology centers like European Centre for Medium-Range Weather Forecasts, Met Office, and Japan Meteorological Agency, and scientific assessments by groups including International Union for Conservation of Nature, Environmental Protection Agency, and World Bank projects on environmental health.

Instruments and Design

TOMS instruments were compact imaging spectrometers using bandpass filters and photomultiplier detectors developed with industry partners such as Hewlett-Packard, RCA, and Honeywell. Design features incorporated tradecraft from predecessors like instruments on Nimbus 4 and heritage engineering used by TRMM teams, while later models borrowed processor architectures similar to those in Landsat missions and pointing systems from GOES platforms. Calibration relied on ground facilities at NASA Ames Research Center, cross-calibration campaigns with balloon flights from National Center for Atmospheric Research and CNES teams, and vicarious methods referencing standards at National Institute of Standards and Technology. Engineering collaborations involved contractors including Raytheon, General Dynamics, and test ranges at White Sands Missile Range.

Mission History and Platforms

The TOMS program began with the instrument on Nimbus 7 (launched 1978), followed by a TOMS sensor on Meteor-3 in collaboration with Soviet Union partners, the Space Shuttle era considerations, a dedicated Earth Probe satellite in 1996, and a final instrument aboard the AURA observatory concept that coordinated with missions like EOS-AM1 and both polar-orbiting and sun-synchronous platforms. Operations involved mission control centers such as Goddard Space Flight Center and data distribution through archives at NASA Langley Research Center and international repositories maintained by European Space Agency. Program milestones coincided with events like the discovery of the Antarctic ozone hole, international negotiations culminating in the Montreal Protocol, and the satellite servicing debates surrounding Hubble Space Telescope missions.

Data Processing and Products

TOMS data processing pipelines were developed by teams at NASA Goddard Space Flight Center, University of Maryland, University of Illinois Urbana-Champaign, and National Oceanic and Atmospheric Administration laboratories, producing Level 1 radiances, Level 2 gridded total ozone columns, and higher-level composites used by analysts at NOAA National Centers for Environmental Information and modelers at European Space Agency centers. Products included daily global ozone maps, UV dose indices used by public health agencies such as World Health Organization, and input fields for chemistry-climate models at NCAR, Max Planck Institute for Meteorology, NASA Jet Propulsion Laboratory, and operational assimilation systems at ECMWF. Data formats adhered to standards promoted by Committee on Earth Observation Satellites and were disseminated through networks including Global Telecommunication System and the Distributed Active Archive Center system.

Scientific Contributions and Applications

TOMS datasets underpinned seminal research by groups at British Antarctic Survey, University of Bristol, University of Cambridge, Columbia University, Harvard University, and international consortia that quantified seasonal and interannual ozone variability, linked chlorofluorocarbon emissions to ozone depletion, and supported attribution studies used by the Intergovernmental Panel on Climate Change and United Nations Environment Programme. Applications extended to ultraviolet exposure forecasting for agencies like Centers for Disease Control and Prevention, agricultural impact assessments for Food and Agriculture Organization, and aviation radiation guidance for organizations including International Civil Aviation Organization. TOMS facilitated multisensor synergy with instruments on platforms such as ERS-2, ENVISAT, OCO, and Suomi NPP to study stratosphere-troposphere exchange, volcanic aerosol impacts, and long-range transport events analyzed by research teams at Scripps Institution of Oceanography and Lamont-Doherty Earth Observatory.

Limitations and Calibration Issues

Limitations included band-limited spectral sampling, susceptibility to contamination from tropospheric aerosols produced by events cataloged in Volcanic Explosivity Index records like eruptions at Mount Pinatubo and Eyjafjallajökull, and degradation of detectors over long-duration missions similar to issues encountered by instruments on Landsat 7 and NOAA satellites. Cross-comparison studies conducted by researchers at NOAA, ESA, JAXA, CNES, and universities revealed biases requiring intercalibration with sondes from World Ozone and Ultraviolet Radiation Data Centre and ground networks run by Global Atmosphere Watch. Algorithmic challenges paralleled those in retrievals from instruments on OMI, GOME, and SCIAMACHY, prompting methodological work at Massachusetts Institute of Technology and University of Oxford.

Legacy and Successors

TOMS legacy persisted through successor sensors and programs including the Ozone Monitoring Instrument on the Aura satellite, European instruments such as GOME-2 on MetOp, and commercial scientific payloads developed by companies like Ball Aerospace and Maxar Technologies. The dataset informed policy and instrument design practices adopted by agencies including NASA, European Space Agency, NOAA, JAXA, and academic consortia at University of Leeds and University of Tokyo. Long-term archives are maintained at centers such as NASA Goddard Space Flight Center and used by contemporary research groups studying climate interactions involving stratospheric chemistry, polar processes at British Antarctic Survey, and air quality dynamics in megacities studied by Peking University and Indian Institute of Science.

Category:Atmospheric physics satellites