The differential heating and cooling of land and water creates low pressure on the landmass of India while the seas around experience comparatively high pressure. This is because the monsoon picks up additional moisture from the Bay of Bengal as it heads towards the Himalayan range. This period covers approximately half of the year and is when the majority of the rainfall for the year will fall in this area. Shillong, a mere 40 km away on top of the Khasi hills, receives only about 140 cm of rainfall during June-September. The reversal of wind direction is caused by the greater annual temperature differences over large land masses than over the adjacent waters.
Much expensive than Mechanical mouse. The monsoon system of the Indian subcontinent differs considerably from that of the rest of Asia. As a result, by May the southwest monsoon is well-established over , an island off the southeastern tip of the Indian peninsula. External links Wikimedia Commons has media related to. Conversely, low pressure over Darwin bodes well for precipitation quantity in India.
However, because of the which causes winds in the Northern Hemisphere to turn right, whereas winds in the Southern Hemisphere turn left , these southeast trade winds are deflected east in the , transforming into southwest trades. The inclusion of the and monsoons with incomplete wind reversal has been debated. As winds blow from the ocean to the land, moist air is brought inland. Despite numerous predictions by the meteorological department, it's rare that anyone gets it right though! Then the land cools faster than the oceans and the air over the land has higher pressure than air over the ocean. These temperature imbalances happen because oceans and land absorb heat in different ways: bodies of water are more slow to heat up and cool down, while land both heats and cools quickly.
Thus monsoons are seasonal winds that change their direction of flow with the change of season. Monsoon winds at the surface blow from heat sink to heat source. Only part of the northeast monsoon passing over the Bay of Bengal picks up moisture, causing rain in and during the winter months. Over three-quarters of annual rainfall in Northern Australia falls during this time. The Asian Monsoon, Wang, B. The landmass of the Indian subcontinent cools up around September with the sun retreating south.
Presence of High Pressure Area, East of Madagascar a. The presence of the high-pressure area, east of Madagascar, approximately at 20°S over the Indian Ocean. A delay of a few days in the arrival of the monsoon can badly affect the economy, as evidenced in the numerous droughts in India in the 1990s. The movement of the westerly jet stream to the north of the Himalayas and the presence of the tropical easterly jet stream over the Indian peninsula during summer. However, when the air rises, and while it is still over the land, the air. To understand the mechanism of the monsoons, the following facts are important. These are the most monitored components of the monsoon, and they determine the water availability in India for any given year.
The retreating monsoon winds move over the Arabian Sea and the Bay of Bengal, and collect moisture on the way. During summer it shifts its position to the Ganga plain, and is also known as monsoon trough, during the monsoon season. Winds move from a high-pressure area to a low-pressure area. The Southern Oscillation is connected to la nina, which is a warm ocean current that flows past the Peruvian Coast. Future changes in the monsoon will depend on a competition between land and ocean—on which is warming faster than the other.
Thus on the whole monsoon is essential for rainy season in India but the imbalance in its routine also causes major problems and we can consider these as its demerits. Westerly Jet Stream and Tropical Easterly Jet Stream a. Changes in the pressure conditions over the southern oceans also affect monsoons. These data, though widely separated from one another, are positively correlated and may be used as predictors of June conditions. By December end, the monsoons have completely withdrawn from India. In summer, the equatorial trough normally positioned about 5°N of the equator moves over the Ganga plain creating a monsoon trough during the monsoon season.
On the other hand, the upper tropospheric easterlies become stronger and a true easterly jet stream. Typically, it is a wind particular to southern Asia that causes therainy season. Additionally, the arrival date and the departure date of both the southwest and northeast monsoon should be close to the mean dates. The and adjoining areas of the northern and central Indian subcontinent heat up considerably during the hot summers. One of it's branch moves westwards along Gangetic plain as far as Punjab. Places like and the Western Ghats get a large number of tourists, both local and foreigners, during the monsoon season.