EGU22-4665, updated on 27 Mar 2022
https://doi.org/10.5194/egusphere-egu22-4665
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

A CMIP6 evaluation of summer synoptic circulations linked to short-term droughts over Europe

Pedro Herrera Lormendez1, Amal John2, Hervé Douville2, and Jörg Matschullat1
Pedro Herrera Lormendez et al.
  • 1TU Bergakademie Freiberg, Interdisciplinary Environmental Research Centre, Germany (pedro.herrera-lormendez@ioez.tu-freiberg.de)
  • 2Centre National de Recherches Météorologiques, Université de Toulouse, Météo-France, CNRS

Automated classifications of atmospheric circulations are a well-known tool to characterize large-scale patterns that predominantly determine day-to-day weather variations. Through its potential influence on the relative frequency of circulation patterns, global warming can also enhance or mitigate the occurrence of extreme weather events.

Here, we use a subset of 22 CMIP6  global climate models (GCMs) to assess their ability to capture these recurrent circulation patterns and their implication for the European climate and its projected changes.

We investigate links between synoptic circulations and short-term meteorological drought events that span one month. We employ the automated Jenkinson-Collison classification to determine daily atmospheric features based on mean sea-level pressure. We compute the conditional probability of dry days related to each circulation type. Furthermore, we confirm the influence of these patterns on the occurrence of dry months by computing the monthly relative frequency anomalies of the synoptic circulations given months where the Standardized Precipitation Index (SPI) was below minus 1. We evaluate the ability of the historical runs of global climate models (GCMs) to reproduce the observed features from the ERA5 reanalyses over the 1961-1990 reference period. Links between the mean directional flow characteristics of the circulation types and the dry days and months are well represented by most GCMs. The most robust relationships were found for the anticyclonic, easterly, and low flow types. These circulations are generally associated with a lack of precipitation and therefore show higher than average occurrences during dry months. 

How to cite: Herrera Lormendez, P., John, A., Douville, H., and Matschullat, J.: A CMIP6 evaluation of summer synoptic circulations linked to short-term droughts over Europe, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-4665, https://doi.org/10.5194/egusphere-egu22-4665, 2022.

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