Hence, in spite of the presence of great regional variations, it has a unifying influence upon the country and its people. Monsoon withdrawal By August the intensity and duration of have decreased, temperatures begin to , and the surge of southwesterly air diminishes spasmodically almost to a standstill in the northwest. The low-pressure conditions over northwestern India move to the Bay of Bengal by early November. Winter Monsoons: The stable, dry anti-cyclonic winds prevailing over the subcontinent after the retreat of the south-west monsoons are not capable of causing precipitation because they are free of moisture. The opposite shift is also possible, with midlatitude upper air flowing along the south face of the Himalayas and bringing drought to the northern districts. The rainfall occurs for a few months in the year, i.
The Mauritius is a small island formed around a central plateau. During their long journey, these winds pick up large amounts of moisture and by the time they reach India they are oversaturated. As the Aravallis have an almost north-south axis, they fail to block the passage of these monsoon currents which rather blow parallel to the Aravallis and lift them. This results in the southwest monsoon. In India, the southwest summer monsoon is attracted by a low pressure area that's caused by the extreme heat of the Thar Desert and adjoining areas, during summer. This is the rain-fed cropped area. Because the southwest monsoon flows from sea to land, it carries more moisture, and therefore causes more rain, than the northeast monsoon.
Mawsynram is flanked on all sides by the Garo, Khasi and Jaintia hills except for a gap through which the rain-bearing winds enter and are forced to rise, thus yielding the heaviest rainfall. Kanyakumari in Tamil Nadu, on the southernmost tip of India, receives the first rainfall. Geographical location latitude, coastal or continental position and physical settings e. Places like and the Western Ghats get a large number of tourists, both local and foreigners, during the monsoon season. The amount of rainfall varies from time to time, often resulting in floods and droughts.
Yet, anyhow many scientists have developed certain theories and observed many patterns of climatic actions to clarify how this phenomenon happens. Indian Ocean The is the third largest oceanic divisions in the world and covers one-fifth of the total ocean waters. In negative dipole years, the reverse happens, making Indonesia much warmer and rainier. The mighty Himalayas produce hydro-dynamic effects that determine the type of precipitation in India. The movement of the monsoon trough determines the spatial distribution of rainfall.
The monsoon wind blows from the northeast towards the sea in winter the dry monsoon and from the southwest towards the land in summer the wet monsoon. Some basins have a lower depth such as the Arabian Sea with 3000 m 9842 ft over most of its area, and the Bay of Bengal from 4000 m 13123 ft south of Sri Lanka to 2000 m 6561. Travel to this region should definitely be avoided during monsoon time, unless you really love the rain! These conditions are unfavourable for precipitation in Kachchh and western Rajasthan where desert conditions prevail. The average annual rainfall in Bangladesh varies from 1500 mm in the west-central part to over 3000 mm in the northeast and southeast. At about 6,000 metres 19,700 feet an cell arises, causing a strong easterly flow in the upper troposphere above northern India.
Accompanying this process and helping this pull of wind regimes is the development of some high pressure centres—in the Indian Ocean, Arabian Sea and over Australia it being the winter season in Australia. The amount of rainfall during the is season varies from 1000 mm in the west-central part of the country to over 2000 mm in the south and northeast. The wind patterns which are prevalent south of the equator are actually the south-east trade winds which blow from the south-east towards the north-west. The winter monsoon is experienced in the states of Karnataka, Tamil Nadu, Kerala and Andhra Pradesh in the first week of January. The converse happens during the summer months. Like the Western Ghats of India in the case of the Arabian Sea branch, the windward slopes of the West Coast Mountains of Myanmar Arakan and Tenasserim mountains get heavy rainfall when the main monsoon currents of this branch strike the Myanmarese coast. Frost also argues that the advent of monsoon does not follow the northward displacement of the jet stream, rather it follows the latter.
Nearly 80 per cent of rains in India are caused by the south-west monsoons during June-September. At the same time, a low-pressure system develops over Australia and the Indian Ocean where it is warmer. The Western Ghats rise abruptly from the of the subcontinent, making effective orographic barriers for the monsoon winds. These disturbances cause upto 5 cm rainfall in Punjab and Kashmir and up to 2. Describe the distribution of the rainfall comment of the areas which receive the highest and lowest amounts.
Again, higher rainfall in the northeast is caused by the additional optional uplifting effect of the Meghalaya plateau. Since 2003, two new models were introduced, which used 8 and 10 parameters instead of 16 to predict monsoon. As a result, the areas lying north of the equator tropics and sub-tropics - get a progressive high incidence of solar radiation. They are affected by different atmospheric conditions encountered by it. Despite progress in alternative forms of irrigation, agricultural dependence on the monsoon remains far from insignificant.
That can be seen clearly in satellite pictures case of a well-developed cyclone, is small and almost circular; it coincides with area lowest pressure has a diameter ranging from 8 km to 50 km. This project involved simulated runs of historical data from 1985 to 2004 to try to establish the relationship of five atmospheric general circulation models with monsoon rainfall distribution. As the Tropic of cancer passes through the country, a tropical climate prevails. This has a dampening effect on economic growth. The energy for the tropical easterly jet stream comes from three sources— i intense heating of middle and upper troposphere above the Tibetan plateau; ii large amounts of latent heat released by the south-west monsoon over the Indian sub continent; and iii heat transfer from elevated surfaces of the Himalayas and-Tibet to the upper atmospheric anti-cyclone. These winds bring abundant moisture to the subcontinent.
Cyclones A cyclone is a tropical storm or atmospheric turbulence involving circular motion of winds. The two currents travel in a clockwise and counter-clockwise direction. The driest period comes in November in the ; December in central India, Bengal, and Assam; January in the northern Deccan; and February in the southern Deccan. The south-west wands now approaching the Indian peninsula have to travel a long distance over the Indian Ocean. The high temperature during the summer over the , as well as over in general, is believed to be the critical factor leading to the formation of the tropical easterly jet over India. Classical Theory or Thermal Concept of Indian Monsoons: According to this theory, the differential heating of land and sea at the time when the sun makes an apparent northward movement is the main cause of the Indian monsoonal regime. The rain in this period is caused by conventional storms thunderstorm or nor-westers locally called a kal Baiskhkhi.