Climate and Monsoon — UPSC Mains Model Answer

During summer, the TP absorbs intense solar radiation and heats the overlying atmosphere through sensible heat flux, effectively acting as an elevated heat source. This creates a strong upper-tropospheric anticyclone — the Tibetan High — which is a defining feature of the mature monsoon circulation. The divergence associated with this anticyclone reinforces the low-level convergence over the Indian subcontinent, sustaining monsoon rainfall.

The thermal gradient between the heated TP and the relatively cooler Indian Ocean drives a meridional pressure difference that helps draw the Inter-Tropical Convergence Zone northward. This elevated heating supplements the land-sea thermal contrast, accelerating the onset and northward advance of the southwest monsoon. Without TP heating, climate models suggest the monsoon would be weaker and confined to lower latitudes.

In winter, the TP acts as a cold sink and a mechanical barrier rather than a heat source. It blocks cold continental air from penetrating southward and deflects westerly jet streams. The northeast monsoon over peninsular India is primarily driven by the withdrawal of the southwest monsoon and differential cooling over the Bay of Bengal, not by TP heating — making Statement 3 incorrect.

Accelerated warming and glacial retreat on the TP are altering its thermal characteristics, with implications for monsoon onset, intensity, and distribution. Agrarian planning, water resource management, and disaster preparedness in India increasingly depend on accurate modelling of TP-monsoon teleconnections.