Tibetan Plateau heating and the monsoon
Topic: Climate of India and the Monsoon · NCERT: Beyond NCERT
Meaning
The Tibetan Plateau is about 4,000 m high. In summer the sun heats its surface strongly, and the plateau warms the upper air above it. The warm air creates high pressure high in the sky, called "high pressure aloft".
Air flowing out of this upper high helps form the tropical easterly jet. This is a fast, narrow wind blowing from east to west high over the Indian peninsula. The jet strengthens the southwest monsoon. This idea was put forward by Koteswaram in 1958. Heavy spring snow over Eurasia has long been linked with a weaker monsoon, because the land then heats up more slowly.
Example
In a typical June, the plateau north of the Himalayas in Tibet heats strongly. The easterly jet then sets in along about 15°N over peninsular India, and the monsoon rain bursts over Kerala and Maharashtra.
Don't confuse with
- Differential heating of land and water: this is the near-surface contrast between the hot land and the cooler sea, the basis of Halley's thermal theory. Tibetan heating works in the upper air.