Combined Effect of the Tropical Indian Ocean and Tropical North Atlantic Sea Surface Temperature Anomaly on the Tibetan Plateau Precipitation Anomaly in Late Summer

Abstract Precipitation variability over the Tibetan Plateau (TP) depends largely on atmospheric circulation pattern associated with remote oceanic forcing, while contribution of sea surface temperature anomalies (SSTAs) in different ocean basins, especially tropical North Atlantic (TNA), remains unclear. By using multisource data and general model, this study reveals individual combined effects Indian Ocean basin mode (IOBM) TNA SSTA interannual TP precipitation late summer (August). During positive phase IOBM, warm SSTAs induce an anomalous anticyclone Bay Bengal (BOBAC) via Kelvin wave–induced Ekman divergence a resulting anomaly southeastern TP. Simultaneously, eastward-extending wave triggered by overlaps that caused further strengthening BOBAC. In addition, induces easterlies Indo-Pacific, which contribute to thus amplify IOBM affecting precipitation. Moreover, generates westward-extending Walker is responsible for suppressed convection central Pacific, turn triggers Rossby response strengthens As result, strengthened significantly. Particularly, considering 2–3-month lead time SSTA, can be used as predictor anomaly.