It expects a candidate to give a clear account of Mascarene high and its importance in the weather pattern of Indian subcontinent.
Introduction:
This high-pressure region located between 25°S-35°S and 40°E-90°E near the Mascarene Islands in the southern Indian Ocean is a source of Southwest monsoon in India. Since, it is a high pressure are, it is also known as Mascarene high.
Body:
Normally, the high-pressure region starts forming by mid-April and its strength is an important factor which determines the intensity of monsoon in India. its impact on the weather pattern in India is as follows:
A stronger high pressure will produce stronger winds or monsoon current.
If there is a delay in the formation of Mascarene High, there is also the possibility of a delay in the onset of monsoon in India.
Most research says that its strength is determined by the happenings in the Antarctic region.
The position and intensity of this high are considered to be closely linked to the south summer monsoon activity.
But overall, this factor is not often held responsible for delays and poor performance of the monsoon in India. Following figure 1 represents the region of Mascarene high.
Figure 1
According to scientists, the broad belt of high pressure around the Mascarene Islands generates a cross-equatorial flow known as the Somali Jet which brings heavy rain to India’s west coast. A strong, low level jet usually means a strong monsoon over peninsular India.
Winds from Mascarene High head in a north-westerly direction towards the east coast of Africa (Somalia). Here, the topography of Somalia deflects the winds towards the east. Also, after crossing the equator, these winds experience the Coriolis Effect.
Coriolis Force is a pseudo force which exists only because of the Earth’s rotational effect. Rotational motion observed in a tropical cyclone is also due to this force.
Hence, these monsoon winds get deflected eastwards and now they blow from south-west to the north-east direction. They split into two branches—the Arabian Sea branch and the Bay of Bengal branch.
In this way Mascarene high impacts the weather pattern in India by creating a way and safe passage for the arrival of monsoon winds in India.
Conclusion:
Since, south west monsoon plays the most prominent role for water availability in India. The role played by Mascarene high also needs to be understood well by investing more in research and developments related to the mechanisms along Indian ocean and Mascarene high.
