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Instrument Drift Uncertainties and the Long-Term TOMS/SBUV Total Ozone RecordLong-term climate records from satellites are often constructed from the measurements of a sequence of instruments launched at different times. Each of these instruments is calibrated prior to launch. After launch they are subjected to potential offsets and slow drifts in calibration. We illustrate these issues in the construction of a merged total ozone record from two TOMS and three SBUV instruments. This record extends from late 1978 through the present. The question is "How good are these records?". We have examined the uncertainty in determining the relative calibration of two instruments during an overlap period in their measurements. When comparing a TOMS instrument, such as that on Nimbus 7, with an SBUV instrument, also on Nimbus 7, we find systematic differences and random differences. We have combined these findings with estimates of individual instrument drift into a monte- carlo uncertainty propagation model. We estimate an instrument drift uncertainty of a little larger than 1 percent per decade over the 25-year history of the TOMS/SBUV measurements. We make an independent estimate of the drift uncertainty in the ground-based network of total ozone measurements and find it to be of similar, but slightly smaller magnitude. The implications of these uncertainties for trend and recovery determination will be discussed.
Document ID
Document Type
Conference Paper
Solarski, Richard S. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Frith, Stacey (Science Systems and Applications, Inc. Lanham, MD, United States)
Date Acquired
August 23, 2013
Publication Date
January 1, 2005
Subject Category
Spacecraft Instrumentation and Astrionics
Meeting Information
Spring 2005 AGU Meeting(New Orleans, LA)
Distribution Limits
Work of the US Gov. Public Use Permitted.