Articles | Volume 13, issue 9
Research article
21 Sep 2017
Research article |  | 21 Sep 2017

Influence of solar variability on the occurrence of central European weather types from 1763 to 2009

Mikhaël Schwander, Marco Rohrer, Stefan Brönnimann, and Abdul Malik

Abstract. The impact of solar variability on weather and climate in central Europe is still not well understood. In this paper we use a new time series of daily weather types to analyse the influence of the 11-year solar cycle on the tropospheric weather of central Europe. We employ a novel, daily weather type classification over the period 1763–2009 and investigate the occurrence frequency of weather types under low, moderate, and high solar activity level. Results show a tendency towards fewer days with westerly and west-southwesterly flow over central Europe under low solar activity. In parallel, the occurrence of northerly and easterly types increases. For the 1958–2009 period, a more detailed view can be gained from reanalysis data. Mean sea level pressure composites under low solar activity also show a reduced zonal flow, with an increase of the mean blocking frequency between Iceland and Scandinavia. Weather types and reanalysis data show that the 11-year solar cycle influences the late winter atmospheric circulation over central Europe with colder (warmer) conditions under low (high) solar activity.

Short summary
We used a new classification of daily weather patterns to analyse the influence of solar variability (11-year cycle) on European climate from 1763 to 2009. The analysis of the weather patterns occurrences shows a reduction in the number of days with a westerly flow over Europe under low solar activity during late winter. In parallel, the number of days with an easterly flow increases. Based on these results we expect colder winter over Europe under low solar activity.