Understanding the Role of Land-Atmosphere Interactions in the Intensification of Compound Heat and Drought Events

Extreme heat poses significant threats to human life and ecosystems in the Earth system. Heatwaves and concurrent droughts have been suggested to intensify and propagate via land-atmosphere interactions and feedbacks. Assessing the feedbacks affecting the spatiotemporal propagation of drought and heatwave events remains challenging, especially when trying to disentangle the effects of local vs remote land conditions on peak temperature. Here, we use ERA-5 reanalysis and the Global Land Evaporation Amsterdam Model (GLEAM) datasets to study atmosphere and land characteristics surrounding the hottest day of the year from 1980 to 2022 to better understand the storylines leading to hot days at specific locations. We also employ simple atmospheric and land models to investigate specific mechanisms and establish causal effects that can explain observed features of compound heat and drought.