Comparison of Nimbus-7 TOMS Version 6 and 7 Ozone Fields by Space-time Spectral Analysis

摘要

Total column ozone fields from Nimbus-7 Total Ozone Mapping Spectrometer (TOMS) version 7 (V7) data are analyzed by space-time spectral analysis and compared with previous analyses of version 6 (V6) data. One purpose of this note is to briefly comment on some differences between these two data sets. A second purpose is to help prospective TOMS users avoid several pitfalls inherent in analyzing TOMS data. Among the differences noted are improvements in the treatments of the known wave 1 low latitude feature and of large solar zenith angles effects at high latitudes. A variety of low amplitude, traveling features are notes, some of which are atmospheric in origin and some of which may be related to the satellite orbital characteristics or retrieval methods. Interpretations of these in terms of atmospheric dynamics should thus be made with care. Overall, the sensitive tests provided by space-time decomposition suggest that TOMS version 7 constitute an improved global data set valuable for investigations of total ozone.