Impacts of Spring Soil Moisture over the Tibetan Plateau on Summer Precipitation in Eastern China

Abstract Soil moisture (SM) plays a critical role in climate regulation through its influence on water and energy cycles. However, its specific impact on precipitation remains uncertain. In this study, we applied the singular value decomposition method to identify a dipole pattern of spring SM over the Tibetan Plateau (TP), characterized by positive anomalies in the east and negative anomalies in the west. This dipole is strongly associated with summer precipitation in eastern China. This dipole pattern is associated with enhanced summer precipitation in the middle and lower reaches of the Yangtze River valley (MLYRV; R = 0.65) and northern China (NC; R = 0.22) and with reduced precipitation in southern China (SC; R = −0.84). Furthermore, the spring SM anomalies persist into summer, modulating land–atmosphere interactions and resulting in increased diabatic heating over the eastern TP and decreased heating over the western TP. This heating contrast pattern induces an anomalous cyclone over NC and an anticyclone over SC during summer. Consequently, the anomalous anticyclone favors descending motion and water vapor divergence, causing reduced precipitation in SC. Conversely, the anomalous cyclone favors ascending motion and moisture convergence, leading to increased precipitation in NC. Moreover, the convergence of warm, moist southerly airflow induced by the anomalous anticyclone, with cold northerly airflow driven by the anomalous cyclone, results in the excessive summer precipitation in the MLYRV. Accordingly, our study highlights that spring SM over the TP (TPSM) can effectively serve as a predictor for summer precipitation variability in eastern China. Significance Statement Forecasting summer precipitation has been a major concern and challenge for meteorologists. This study investigates the influence of spring soil moisture (SM) over the Tibetan Plateau (TP) on summer precipitation in eastern China. Understanding the linkage between spring SM and summer precipitation provides valuable insights for seasonal prediction in the region. The results reveal that wet anomalies over the eastern TP and dry anomalies over the western TP are associated with increased summer precipitation in the middle and lower reaches of the Yangtze River valley (MLYRV) and northern China (NC) and decreased precipitation in southern China (SC). This linkage is attributed to the persistence of spring SM anomalies, which alter land–atmosphere interactions and lead to enhanced summer diabatic heating over the eastern TP and reduced heating over the western TP. This anomalous heating pattern over the TP induces an anomalous cyclone over NC and an anticyclone over SC. These circulation anomalies enhance precipitation in the MLYRV and NC, while suppressing it in SC. The findings imply that spring SM over the TP can serve as a predictor of summer flooding or drought in eastern China.