Influence of Soil Moisture on Surface Air Temperature in Monsoons

Land plays a pivotal role in modulating weather and climate in monsoon regions, yet our understanding of land–atmosphere interactions remains incomplete. Here we present the information-theoretic causal analysis, the Liang-Kleeman information flow, for quantifying the strength of soil moisture (SM) influence on surface air temperature (SAT). We revealed that SM exerts significant influence on SAT across monsoon regions, intricately linked to the seasonal monsoon cycle. Notably, prominent influence of SM on SAT was found, even under typical wet conditions in the tropics when intense solar radiation is present. Furthermore, this study highlights a strong connection between land desiccation and the occurrence of hot days in pre-monsoon periods. The proposed measure of SM influence strength enhances our understanding of land–atmosphere interactions and provides new insights into seasonally evolving predictability arising from SM variability across monsoon systems.