Land–atmosphere feedbacks and dry extremes under changing climate: assessment of missing cause–effect relationships in observations and models

Droughts have profound negative implications on humans and the environment. Global warming is expected to exacerbate these events in certain regions, aggravating their impacts on people and ecosystems. However, confidence in past and future drought predictions from climate models remains low. Lack of understanding of land–atmosphere interactions during droughts is one of the reasons for this inherent uncertainty. Recent studies were able to demonstrate how soil dryness aggravates droughts at the surface by accelerating warming of the air and the evaporation from the soil. However, the effect of soil dryness on the likelihood of precipitation during droughts remains largely unexplored. In this project, I propose to use a unique combination of recent satellite-based observations, existing coupling metrics and a novel mechanistic framework to explore this feedback, globally and over multiple drought events. Results will reveal: (1) if dry soils play a role in meteorological drought persistence, (2) in which global regions this soil moisture–precipitation feedback is critical for drought evolution and termination, (3) how this feedback has changed over the past decades, and (4) what the skill of the IPCC climate models at representing this feedback during droughts is. The results will help increase the accuracy of future drought predictions.