When the southeast trade winds cross the equator, they are perceived in the Northern Hemisphere as equatorial westerlies because they seem to blow from the equator toward the Tropic of Cancer. The North American monsoon (NAM) occurs from late June or early July into September, originating over Mexico and spreading into the southwest United States by mid-July. [43] In some places there is just a likelihood of having a little more or less rain. But with continuous dropping pressure, sufficient force is created for the movement of the westerly jet across the Himalayas after a significant period. Therefore, the agricultural calendar of India is governed by the monsoon. [29] Further, the two poles of the IOD – the eastern pole (around Indonesia) and the western pole (off the African coast) — independently and cumulatively affect the quantity of monsoon rains. [29], As with ENSO, the atmospheric component of the IOD was later discovered and the cumulative phenomenon named Equatorial Indian Ocean oscillation (EQUINOO). It affects Mexico along the Sierra Madre Occidental as well as Arizona, New Mexico, Nevada, Utah, Colorado, West Texas and California. Visser, S.W. Over India, a subtropical westerly jet develops in the winter season and is replaced by the tropical easterly jet in the summer season. The mechanism affecting the monsoon is that the westerly jet causes high pressure over northern parts of the subcontinent during the winter. This makes the Arabian Sea (the western Indian Ocean near the African coast) much warmer and the eastern Indian Ocean around Indonesia colder and drier. Find more similar words at wordhippo.com! The semiarid Sahel and Sudan depend upon this pattern for most of their precipitation. The Himalayas play more than the role of orographic barriers for the monsoon. [12] One area that monsoons impact greatly is India. As such, the shift of the jet is sudden and abrupt, causing the bursting of southwest monsoon rains onto the Indian plains. The jet streams are systems of upper-air westerlies. Thus a better understanding of the possible links between El Niño, Western Pacific Warm Pool, Indonesian Throughflow, wind pattern off western Australia, and ice volume expansion and contraction can be obtained by studying the behaviour of the LC during Quaternary at close stratigraphic intervals.[16]. 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 winds arrive at the Eastern Himalayas with large amounts of rain. After the arrival at the Eastern Himalayas, the winds turns towards the west, travelling over the Indo-Gangetic Plain at a rate of roughly 1–2 weeks per state,[32] pouring rain all along its way. A host of mosquito-borne, water-borne and air-borne infections become more common as a result of the change in the ecosystem. Thus these five intervals could probably be those of considerable lowering of SST in the Indian Ocean and would have influenced Indian monsoon intensity. [42], The Centre for Development of Advanced Computing (CDAC) at Bengaluru facilitated the Seasonal Prediction of Indian Monsoon (SPIM) experiment on the PARAM Padma supercomputing system. It states that during the hot subtropical summers, the massive landmass of the Indian Peninsula heats up at a different rate than the surrounding seas, resulting in a pressure gradient from south to north. It is believed that the resulting increase in sea surface temperatures in the Indian Ocean increased the intensity of monsoons. As the land's surface becomes warmer, the air above it expands and an area of low pressure develops. As such, it affects the environment (and associated flora, fauna, and ecosystems), agriculture, society, hydro-power production, and geography of the subcontinent (like the availability of fresh water in water bodies and the underground water table), with all of these factors cumulatively contributing to the health of the economy of affected countries. These create areas of low air pressure above coastal lands compared with pressure over the seas, causing winds to flow from the seas onto the neighboring lands. "Initiation of Northern Hemisphere glaciation and strengthening of the northeast Indian monsoon: Ocean Drilling Program Site 758, eastern equatorial Indian Ocean", 10.1130/0091-7613(2003)031<0047:IONHGA>2.0.CO;2, "Ocean circulation in the tropical Indo-Pacific during early Pliocene (5.6–4.2 Ma): Paleobiogeographic and isotopic evidence", "Sea breeze – definition of sea breeze by The Free Dictionary". Because of differences in the specific heat capacity of land and water, continents heat up faster than seas. This crowds city slums and aggravates the infrastructure and sustainability of city life. Places like Kerala and the Western Ghats get a large number of tourists, both local and foreigners, during the monsoon season. Meanwhile, the ocean remains at a lower temperature than the land, and the air above it retains a higher pressure. As the Tibetan Plateau heats up, the low pressure created over it pulls the westerly jet north. When this happened, cold waters in the Pacific were impeded from flowing into the Indian Ocean. ), Most summer monsoons have a dominant westerly component and a strong tendency to ascend and produce copious amounts of rain (because of the condensation of water vapor in the rising air). The Australian monsoon (the "Wet") occurs in the southern summer when the monsoon trough develops over Northern Australia. Since the Great Famine of 1876–78 in India, various attempts have been made to predict monsoon rainfall. As such, during the northern summer (May and June), the ITCZ moves north, along with the vertical sun, toward the Tropic of Cancer. Kitkatwords.com, Copyright © 2020. But with the advent of globalization, such travel is gaining popularity. According to this theory, the onset of the southwest monsoon is driven by the shift of the subtropical westerly jet north from over the plains of India toward the Tibetan Plateau.