An analysis of the causes of Kenya’s extreme drought event in May 2023

Abstract

In the context of global warming, the East African region has experienced frequent droughts, with severe impacts on local society and livelihoods. Kenya, in particular, is one of the most drought-affected countries in the region. In May 2023, Kenya experienced an unprecedented extreme drought event that posed a serious threat to the lives and property of the local population. This study focuses on this event, and through quantitative diagnostic analysis, tentatively examines the main controlling factors and possible influencing mechanisms that affect rainfall in Kenya during this event. The analysis results indicate that the anomalous vertical atmospheric motion in 2023, which influences the transport process of the vertical gradient of water vapor, is the main controlling factor of the Kenyan drought event, with the anomalous descending airflow playing a dominant role. Further analysis shows that the anomalous warming of sea surface temperatures in the southwestern Indian Ocean in May 2023 triggered an anticyclonic circulation over the western Indian Ocean, which significantly influenced the anomalous vertical atmospheric motion. This research provides a preliminary explanation of the causes of the drought event from an air-sea interaction perspective.