Variability and Trends in Stratospheric Temperature and Water Vapor

Abstract

The Stratosphere: Geophysical Mon Copyright 2010 b 10.1029/2009GM Long-term variability and trends in global stratospheric temperature are described, based on radiosonde observations since the 1960s and satellite measurements since 1979. New radiosonde-based data sets are available that include adjustments for instrumental inhomogeneities, and these data show good agreement with satellite measurements in the lower stratosphere. The stratosphere exhibits well-known transient warming linked to large volcanic eruptions, plus long-term cooling with magnitudes ~ 0.5 K/decade in the lower stratosphere to ~ 1.2 K/decade in the upper stratosphere. Observations of stratospheric water vapor are also analyzed, based on satellite measurements for 1993–2010. Observed interannual variability is dominated by the quasi-biennial oscillation, plus a step-like drop after 2001. For the observed satellite record, variability in stratospheric water vapor is closely tied to temperature anomalies near the equatorial cold point tropopause.