EGU22-1381
https://doi.org/10.5194/egusphere-egu22-1381
EGU General Assembly 2022
© Author(s) 2022. This work is distributed under
the Creative Commons Attribution 4.0 License.

Uncertainty in projected changes in precipitation minus evaporation: Dominant role of dynamic circulation changes and weak role for thermodynamic changes

Eilat Elbaum1, Chaim I. Garfinkel1, Ori Adam1, Efrat Morin1, Dorita Rostkier-Edelstein1,2, and Uri Dayan3
Eilat Elbaum et al.
  • 1Fredy and Nadine Herrmann Institute of Earth Sciences, Hebrew University, Jerusalem, Israel
  • 2Department of Environmental Physics, Environmental Sciences Division, Israel Institute for Biological Research, Ness-Ziona, Israel
  • 3Department of Geography, Hebrew University, Jerusalem, Israel

End of century projections from Coupled Model Intercomparison Project (CMIP) models show a decrease in precipitation over subtropical oceans that often extends into surrounding land areas, but with substantial intermodel spread. Changes in precipitation are controlled by both thermodynamical and dynamical processes, though the importance of these processes for regional scales and for intermodel spread is not well understood. The contribution of dynamic and thermodynamic processes to the model spread in regional precipitation minus evaporation (P-E) is computed for 48 CMIP models. The intermodel spread is dominated essentially everywhere by the change of the dynamic term, including in most regions where thermodynamic changes dominate the multi-model mean response. The dominant role of dynamic changes is insensitive to zonal averaging which removes any influence of stationary wave changes, and is also evident in subtropical oceanic regions. Relatedly, intermodel spread in P-E is generally unrelated to climate sensitivity.

How to cite: Elbaum, E., Garfinkel, C. I., Adam, O., Morin, E., Rostkier-Edelstein, D., and Dayan, U.: Uncertainty in projected changes in precipitation minus evaporation: Dominant role of dynamic circulation changes and weak role for thermodynamic changes, EGU General Assembly 2022, Vienna, Austria, 23–27 May 2022, EGU22-1381, https://doi.org/10.5194/egusphere-egu22-1381, 2022.

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