Figure 6. Schematic diagram showing the gross structure of the South Asian summer monsoon.

For the southern branch, water vapor along the conveyer belt is lifted up due mainly to land–sea (L_S) thermal contrast in the tropics; for the northern branch the water vapor is drawn away from the conveyer belt northward toward the foothills and slopes of the TP, and is uplifted to produce heavy precipitation that is controlled mainly by IPTP-SHAP; the rest of the water vapor is transported northeastward to sustain the East Asian summer monsoon, which is controlled by the land–sea thermal contrast as well as thermal forcing of the TP.