Characterization of compound occurrence of heat waves and drought in Europe and North America

Extreme events such as heat waves and droughts can have major impacts on agriculture, human health, and the energy sector, especially during the co-occurrence of such events. Although there is evidence that heat waves and drought have increased in intensity and frequency in the last decades, the analysis, characterization, and impact assessment of the compound occurrence of drought and heat waves are not well documented yet in a common framework. There are still some open questions related to how changes in midlatitude circulation may transcend in the thermodynamical characteristics of these compound events in the future. Furthermore, the role of some local feedbacks and the relationship with other extremes are still a debating subject.

The purpose of this research is to shed some light and add evidence about the key drivers related to these extreme events. The main atmospheric characteristics of compound heat waves and drought events in Europe and North America are identified through the analysis of the ERA5 dataset during the historical period (1959-2022). Additionally, we evaluate the ability of CMIP6 models with respect ERA5 to reproduce the statistics of these compound events. Specifically, we aim at understanding what are the climatological characteristics of these events in the historical climate and what are the dynamical mechanisms leading to compound occurrence of heat waves and droughts.