EGU2020-15989
https://doi.org/10.5194/egusphere-egu2020-15989
EGU General Assembly 2020
© Author(s) 2020. This work is distributed under
the Creative Commons Attribution 4.0 License.

Heatwaves and Predictability - the Role of Rossby Waves and Atmospheric Waveguides

Rachel White1, Chloé Prodhomme1,2, Georgios Fragkoulidis3, Stefano Materia4, and Constantin Ardilouze5
Rachel White et al.
  • 1Earth Sciences Department, Barcelona Supercomputing Center, Barcelona, Spain
  • 2Department of Applied Physics, University of Barcelona, Barcelona, Spain
  • 3Institute for Atmospheric Physics, Johannes Gutenberg University Mainz, Mainz, Germany
  • 4Climate Simulations and Predictions Division, Euro-Mediterranean Centre on Climate Change (CMCC), Bologna, Italy
  • 5National Center for Meteorological Research (CNRM), Météo-France, France

Heat waves can have a devastating impact on human society and ecosystems, and thus improved understanding and predictability of such events would provide huge benefits. It has been shown previously that many extreme temperature events are associated with quasi-stationary, or recurrent, Rossby waves (hereafter QSWs). We show that these QSWs are often associated with atmospheric waveguides, providing some dynamical understanding of why such weather patterns persist. In the context of this framework, we study the subseasonal-to-seasonal (S2S) predictability of heatwaves, QSWs, and atmospheric waveguides. Operational seasonal forecasts can reproduce the observed climatological statistics of QSWs, and the observed connection between QSWs and extreme temperatures over Europe, although with some biases. To better understand the underlying dynamics of the seasonal forecast models, we explore whether such models are capable of reproducing the observed connection between QSWs and atmospheric waveguides,  linked to persistent, and thus high impact, extreme heat events. We examine the S2S predictability of atmospheric waveguides and high amplitude QSW events, to better understand the potential S2S predictability of heatwaves.

How to cite: White, R., Prodhomme, C., Fragkoulidis, G., Materia, S., and Ardilouze, C.: Heatwaves and Predictability - the Role of Rossby Waves and Atmospheric Waveguides, EGU General Assembly 2020, Online, 4–8 May 2020, EGU2020-15989, https://doi.org/10.5194/egusphere-egu2020-15989, 2020

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