Speaker
Description
Recent decades have seen a significant rise in the frequency and intensity of droughts and heatwaves globally. The 2022 European summer exemplified how the co-occurrence of heatwave and drought can lead to unprecedented impacts to natural and human systems with up to 50% cross losses and 61 672 heat-related deaths including 434 in Belgium alone. The disproportionate impacts of these compound hot-dry events can be largely attributed to land-atmosphere feedbacks that mutually intensify the surface warming and drying. While research has focused on observing and quantifying this feedback through the soil moisture-temperature coupling, current approaches rely mainly on correlations, and are unable to capture the intrinsically asymmetric directional nature of the interaction between two climate variables leaving a gap in our understanding of these critical events. In this work we use the non-stationary Liang-Kleeman information flow formalism to study the causal soil moisture-temperature coupling. Using ERA5 and ERA5-Land data, we inspect the trends of the causal coupling and inspect its variations during univariate extremes and compound hot-dry events; and investigate the anthropogenic influence on the observed trends using a multi-model, multi-member ensemble. We find spatial patterns and asymmetries in the coupling direction for both the trends and the behavior during extremes, with generally more significant changes for the causal effect of soil moisture on temperature. These results demonstrate the value and potential of causal inference based coupling metrics to advance our understanding of these increasingly impactful and frequent extreme climate events.
| If accepted by the Scientific Board, I agree to have my presentation/poster and abstract published on the Belgian Climate Centre websites and social media. | Yes |
|---|
