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Annales Geophysicae An open-access journal of the European Geosciences Union
Ann. Geophys., 33, 783-788, 2015
https://doi.org/10.5194/angeo-33-783-2015
© Author(s) 2015. This work is distributed under
the Creative Commons Attribution 3.0 License.
ANGEO Communicates
25 Jun 2015
Composite analysis of a major sudden stratospheric warming
K. Hocke1,2, M. Lainer1,2, and A. Schanz1,2 1Institute of Applied Physics, University of Bern, Bern, Switzerland
2Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
Abstract. We present the characteristics of a major sudden stratospheric warming (SSW) by using the composite analysis method and ERA Interim reanalysis data from 1979 to 2014. The anomalies of the parameters total ozone column density (TOC), temperature (T), potential vorticity (PV), eastward wind (u), northward wind (v), vertical wind (w), and geopotential height (z) are derived with respect to the ERA Interim climatology (mean seasonal behaviour 1979 to 2014). The composites are calculated by using the time series of the anomalies and the central dates of 20 major SSWs. Increases of up to 90 Dobson units are found for polar TOC after the SSW. Polar TOC remains enhanced until the summer after the major SSW. Precursors of the SSW are a negative TOC anomaly 3 months before the SSW and enhanced temperature at 10 hPa at mid-latitudes about 1 month before the SSW. Eastward wind at 1 hPa is decreased at mid-latitudes about 1 month before the SSW. The 1 hPa geopotential height level is increased by about 500 m during the month before the SSW. These features are significant at the 2σ level for the mean behaviour of the ensemble of the major SSWs. However, knowledge of these precursors may not lead to a reliable prediction of an individual SSW since the variability of the individual SSWs and the polar winter stratosphere is large.

Citation: Hocke, K., Lainer, M., and Schanz, A.: Composite analysis of a major sudden stratospheric warming, Ann. Geophys., 33, 783-788, https://doi.org/10.5194/angeo-33-783-2015, 2015.
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The composite analysis of major sudden stratospheric warmings (SSW) showed changes in atmospheric parameters at mid-latitudes about 1-2 months before the central date of the SSW. Polar ozone is enhanced during the half year after the SSW event.
The composite analysis of major sudden stratospheric warmings (SSW) showed changes in...
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