Satellite measurements of stratospheric temperature trends over 1979-2015

Long-term variations in stratospheric temperatures are evaluated based on merged satellite observations spanning 1979-2015. We combine measurements from the Stratospheric Sounding Unit (SSU, covering 1979-2005) with observations from the Aura Microwave Limb Sounder (MLS, 2004-2015) and Sounding of the Atmosphere using Broadband Emission Radiometry (SABER, 2002-2014). These data show long-term cooling which increases in magnitude from the lower to upper stratosphere (-0.5 to -0.7 K/decade), in addition to variations linked to the 11-year solar cycle, QBO, ENSO and volcanic effects. The time series provide evidence that upper stratosphere temperatures have responded to observed changes in ozone, in addition to cooling from increases in CO2. Comparisons with the WACCM chemistry-climate model show overall good agreement in the simulation of temperature variability and trends over the past 4 decades.