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Atmospheric synoptic circulations linked to short-term droughts over Europe: A CMIP6 evaluation
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  • Pedro Herrera Lormendez,
  • AMAL JOHN,
  • Hervé Douville,
  • Jörg Matschullat
Pedro Herrera Lormendez
TU Bergakademie Freiberg

Corresponding Author:[email protected]

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AMAL JOHN
Météo-France
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Hervé Douville
Météo-France
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Jörg Matschullat
TU Bergakademie Freiberg
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Abstract

Synoptic circulation classifications represent a helpful tool to characterize daily atmospheric patterns that strongly relate to the dominant regional meteorological conditions. As global warming influences the dynamical response of circulation patterns, their changes might enhance or mitigate the behaviour of extreme weather events. We investigate the synoptic circulations linked to short-term meteorological droughts. The automated Jenkinson-Collison classification is used to classify daily atmospheric patterns, based on mean sea-level pressure data. Links between monthly relative frequency anomalies of the synoptic circulations and short-term meteorological droughts were found using the 1-month Standardized Precipitation Index (SPI-1). We evaluate the ability of the historical runs of global climate models (GCMs) to reproduce the observed features in the ERA5 reanalysis during the 1961 - 1990 climatological reference period. The evaluation is performed by a multi model ensemble (MME) approach based on 22 GCMs. Links between the mean directional flow characteristics of the circulation types and dry months were found and are well represented in the GCMs MME. The strongest relationships were found within anticyclonic, easterly and low flow types since these circulation types show higher than normal occurrences during dry events. Inverse relationships emerged from the dominant westerly directional types given their lower occurrences dominated by the dry months.