A new self-calibration method applied to TOMS and SBUV backscattered ultraviolet data to determine long-term global ozone change

Journal Article · Sat Apr 20 04:00:00 EDT 1991 · Journal of Geophysical Research; (United States)

DOI:https://doi.org/10.1029/90JD02662· OSTI ID:5400624

Herman, J R; Hudson, R; McPeters, R; Stolarski, R ^[1]; Ahmad, Z; Wellemeyer, C ^[2]

---

1. NASA Goddard Space Flight Center, Greenbelt, MD (USA)
2. ST Systems Corp., Lanham, MD (USA)

The currently archived (1989) total ozone mapping spectrometer (TOMS) and solar backscattered ultraviolet (SBUV) total ozone data (version 5) show a global average decrease of about 9.0% from November 1978 to November 1988. This large decrease disagrees with an approximate 3.5% decrease estimated from the ground-based Dobson network. The primary source of disagreement was found to arise from an overestimate of reflectivity change and its incorrect wavelengths dependence for the diffuser plate used when measuring solar irradiance. For total ozone measured by TOMS, a means has been found to use the measured radiance-irradiance ratio from several wavelengths pairs to construct an internally self consistent calibration. The method uses the wavelength dependence of the sensitivity to calibration errors and the requirement that albedo ratios for each wavelength pair yield the same total ozone amounts. Smaller errors in determining spacecraft attitude, synchronization problems with the photon counting electronics, and sea glint contamination of boundary reflectivity data have been corrected or minimized. New climatological low-ozone profiles have been incorporated into the TOMS algorithm that are appropriate for Antarctic ozone hole conditions and other low ozone cases. The combined corrections have led to a new determination of the global average total ozone trend (version 6) as a 2.9 {plus minus} 1.3% decrease over 11 years. Version 6 data are shown to be in agreement within error limits with the average of 39 ground-based Dobson stations and with the world standard Dobson spectrometer 83 at Mauna Loa, Hawaii.

• OSTI ID: 5400624
• Journal Information: Journal of Geophysical Research; (United States), Journal Name: Journal of Geophysical Research; (United States) Vol. 96:D4; ISSN 0148-0227; ISSN JGREA
• Country of Publication: United States
• Language: English

Related Subjects

54 ENVIRONMENTAL SCIENCES
540120* -- Environment
Atmospheric-- Chemicals Monitoring & Transport-- (1990-)
ALGORITHMS
ANTARCTIC REGIONS
ANTARCTICA
BACKSCATTERING
CALIBRATION
COMPARATIVE EVALUATIONS
DATA PROCESSING
ECOLOGICAL CONCENTRATION
ELECTROMAGNETIC RADIATION
HOLES
LAYERS
LOSSES
MATHEMATICAL LOGIC
MEASURING INSTRUMENTS
OPTICAL PROPERTIES
OZONE
OZONE LAYER
PHYSICAL PROPERTIES
POLAR REGIONS
PROCESSING
RADIATIONS
REFLECTIVITY
SCATTERING
SOLAR RADIATION
SPECTROMETERS
SPECTROSCOPY
STELLAR RADIATION
SURFACE PROPERTIES
ULTRAVIOLET RADIATION
VARIATIONS
WAVELENGTHS