Role of land-atmosphere coupling in persistent extreme climate events in eastern China in summer 2022

In 2022, eastern China was wet in the north and dry in the south, and characterized particularly by a persistent compound extreme event with high temperatures, low precipitation, and dry soil during the warm season. Here, the authors investigate the evolution and possible underlying mechanism of this compound extreme event. From May to September in eastern China, there was a clear climate pattern transition from north to south, with noticeable intraseasonal changes in temperature, precipitation, and soil moisture. Different from the long-term climatology of 1940-2022, an enhanced influence of soil moisture on evaporation occurred in the Yangtze River Valley and Southeast China in 2022. These regions, however, are typically where evapotranspiration is limited by the land -surface available energy. Strong feedback between soil moisture and climate elements may have played a crucial role in the evolution and persistence of extreme climate events during the warm season in 2022.