Stratospheric temperature anomalies at the end of 1994 were the lowest in the 15-year record of satellite data (Fig. 1.11) and were also the lowest in the 30-year record of radiosonde-based estimates (Fig. 1.8, bottom). The satellite estimates showed almost continuous cooling in the stratosphere throughout the year for all latitude bands, with the exception of the Southern Hemisphere extratropics.
The global patterns of stratospheric temperature anomalies (Figs. 1.12 and 1.13), show striking interannual variability. The warming effects of the Mt. Pinatubo eruption are evident in the patterns for 1991 and 1992 (Figs. 1.13). Also evident is a strong global cooling that has occurred thereafter, with most regions experiencing a cooler than normal lower stratosphere during 1994 (Fig. 1.12). This cooling continues a trend that began in the early 1980s (Fig. 1.8, bottom).
A quasi-biennial oscillation (QBO) of temperatures is also evident in the tropics and subtropics. This QBO featured positive anomalies during 1990 and 1993 throughout the equatorial region (Fig. 1.13), and negative anomalies along the equator in 1994 (Fig. 1.12). Although the effects of the Mt. Pinatubo eruption dominated the tropics during 1991 and 1992, the QBO can still be noted during that period as a decrease in positive anomalies along the equator from 1990 to 1991.
Climate and Global Change Issues - Trace Gases: Ozone
Climate and Global Change Issues: Troposphere Temperatures
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