Figure 6 – Tibet anti-cyclone and Easterly Jet stream

3.2.2. Role of Jet Stream

As already discussed, sub-tropical westerly jet stream is bifurcated by the high-land Tibet in winters. Northward branch extends up to 20oN-35oN (Figure 6). Tropical easterly jet stream (TEJ), that branch off from anticyclone developed over Tibet, sometimes reaches to the tip of Peninsular India. Apart from this, Jet speed winds are also reported over other parts of Peninsular. This jet descends over the Indian Ocean and intensifies its high pressure cell known as Mascarene High. It is from this high pressure cell that the onshore winds start blowing towards the thermally induced low pressure area, developed in the northern part of the Indian subcontinent. After crossing the equator such winds become south-westerly and are known as the south-westerly summer monsoon.