Topic – Part of static series under the heading – “physiography”
6) Explain how the Himalayan and the Tibetan highlands play an important role in the-development of the South – West monsoon?(250 words)
Key demand of the question
The question expects us to bring out the impact that Himalayas and the Tibetan plateau have on the onset, progress and retraction of south west monsoon in India.
Structure of the answer
Introduction – Explain the geographical presence and physical features of Himalayas and Tibetan plateau.
- Discuss the impact of Himalayas on SW Monsoon – in foothills of Himalayas is location of sub-tropical high pressure(STHP) belt. In summers, pressure belts shift to north so STHP belt also move to the north, which disintegrates the jet stream(which was blowing
originally over northern plains), thus causing a monsoonal trough (vacuum) in this region, thus sucking the SW
monsoonal winds . In addition , Himalayas also prevent the further northward movement of the monsoons and
hence confine them to Indian landmass
Discuss the impact of tibetan highlands- also strengthen SW monsoons by giving birth to tropical easterly jet stream. In summers, the surface of Tibetan plateau become very warm ( warm air always rise) and the warm air rising from Tibet
move south towards Indian ocean because of the precence of STHP belt north of Tibet. These currents of warm
air deflect to their right as they move due to coriolis force and hence sink over Arabian sea. This air picks up
moisture from Arabian sea and joins SW monsoonal winds.