{"id":31468,"date":"2026-10-30T17:13:47","date_gmt":"2026-10-30T11:43:47","guid":{"rendered":"https:\/\/vajiramandravi.com\/upsc-exam\/?p=31468"},"modified":"2026-10-30T17:13:47","modified_gmt":"2026-10-30T11:43:47","slug":"cyclones","status":"publish","type":"post","link":"https:\/\/vajiramandravi.com\/upsc-exam\/cyclones\/","title":{"rendered":"Cyclones, Meaning, Types, Cyclogenesis Mechanism, Impacts"},"content":{"rendered":"<p><span style=\"font-weight: 400\">Cyclones are rotating weather systems that form around a low-pressure centre. At the surface, air moves inward and rises, leading to the formation of clouds, strong winds, and heavy rain. The direction of rotation is anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere. <\/span><span style=\"font-weight: 400\">There are two main types of cyclones: tropical, which are powered by warm ocean waters and the heat released from water vapour condensing, and temperate or extratropical, which form where air masses of different temperatures meet.<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">These weather systems can cause a variety of dangers, including strong winds, storm surges, coastal flooding, heavy rain, and landslides. India is particularly vulnerable to cyclones from both the Bay of Bengal and the Arabian Sea, making accurate forecasting and preparedness essential.<\/span><\/p>\r\n<h2><span style=\"font-weight: 400\">Cyclones Meaning<\/span><\/h2>\r\n<p><span style=\"font-weight: 400\">Cyclones are large-scale atmospheric systems where air circulates around a low-pressure area, converging at the surface and rising. This process often results in the formation of clouds and precipitation. Cyclones form when air flows towards a region of lower pressure, and the rotation of the Earth causes the air to spiral, creating a circular motion. Key features of cyclones include:<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Lower atmospheric pressure at the centre compared to surrounding areas.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The pressure gradient drives air towards low pressure, while the Coriolis effect deflects the moving air and helps organise the circulation.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Air that moves towards the low-pressure area and rises.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Rotational movement that spins anticlockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Formation of clouds and rainfall due to rising moist air cooling and condensing.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Variable strength, ranging from weak disturbances to severe storms with high winds and heavy rain.<\/span><\/li>\r\n<\/ul>\r\n<p><img decoding=\"async\" class=\"wp-image-31499 aligncenter\" src=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182121\/cyclones-1.png\" alt=\"Cyclones\" width=\"852\" height=\"578\" srcset=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182121\/cyclones-1.png 1522w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182121\/cyclones-1-768x521.png 768w\" sizes=\"(max-width: 852px) 100vw, 852px\" \/><\/p>\r\n<h3><span style=\"font-weight: 400\">Fujiwara Effect<\/span><\/h3>\r\n<p><span style=\"font-weight: 400\">The Fujiwhara Effect occurs when two nearby tropical cyclones interact, influencing each other\u2019s movement, direction and intensity. It was described by Japanese meteorologist Sakuhei Fujiwhara in 1921.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Possible outcomes:<\/b><span style=\"font-weight: 400\"> The cyclones may rotate around a common centre, change tracks, move apart or, in some cases, merge. The stronger cyclone may influence or absorb the weaker one.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The outcome (changing tracks, repelling, merging, or absorption of the weaker system by the stronger one) depends on the cyclones\u2019 relative strength, size, distance and atmospheric conditions.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The interaction complicates cyclone-track and landfall predictions, making timely warnings, evacuation planning and disaster preparedness more challenging.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Example:<\/b><span style=\"font-weight: 400\"> 1964 Western Pacific (Typhoons Marie and Kathy): two typhoons interacted and eventually merged in the Western Pacific Ocean.<\/span><\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">Cyclones Naming System<\/span><\/h2>\r\n<p><span style=\"font-weight: 400\">The Cyclones Naming System assigns unique names to individual tropical cyclones to make it easier to communicate warnings and avoid confusion among the public, meteorologists, and disaster management agencies.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The <\/span><a href=\"https:\/\/vajiramandravi.com\/upsc-exam\/world-meteorological-organization-wmo\/\" target=\"_blank\"><span style=\"font-weight: 400\"><strong>World Meteorological Organisation<\/strong><\/span><\/a><span style=\"font-weight: 400\"> (WMO) coordinates the global framework for tropical cyclone naming.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Cyclone names are assigned from the pre-approved regional list. They are not chosen afresh by the country affected by each storm.\u00a0<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The next listed name is used when a subsequent cyclone reaches the required naming intensity.<\/span><\/li>\r\n<\/ul>\r\n<h3><span style=\"font-weight: 400\">Cyclone Naming System in the North Indian Ocean<\/span><\/h3>\r\n<p><span style=\"font-weight: 400\">In the North Indian Ocean, the cyclone naming system is managed by the WMO\/ESCAP Panel on Tropical Cyclones, covering the Bay of Bengal and the Arabian Sea. This system was introduced in September 2004.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The WMO\/ESCAP Panel on Tropical Cyclones comprises 13 member countries that contribute names to the regional list.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The 13 members are listed alphabetically. Names are assigned sequentially, column-wise, from the approved regional list.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The Regional Specialised Meteorological Centre (RSMC), located in New Delhi, is responsible for naming cyclones in the region when they reach the required intensity.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Once a name has been used, it is not repeated.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Names are selected based on criteria such as being short, easy to pronounce, culturally appropriate, distinctive, and suitable across languages.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">They should not be offensive or inappropriate.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The purpose of naming cyclones is to provide quick warning communication, raise public awareness, differentiate simultaneous storms, and maintain records for research.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Recent Examples:<\/b><span style=\"font-weight: 400\"> Cyclone Arnab, which affected Andhra Pradesh and Odisha.<\/span>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">It was named by Bangladesh.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The previous names were Senyar (named by the UAE) and Ditwah (named by Yemen).<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">The next names in the sequence are Murasu (India) and Akvan (Iran).<\/span><\/li>\r\n<\/ul>\r\n<\/li>\r\n<\/ul>\r\n<p><img decoding=\"async\" class=\"wp-image-31500 aligncenter\" src=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182252\/cyclones-2.png\" alt=\"Cyclones\" width=\"872\" height=\"490\" srcset=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182252\/cyclones-2.png 1672w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182252\/cyclones-2-768x432.png 768w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182252\/cyclones-2-1536x864.png 1536w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182252\/cyclones-2-270x152.png 270w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182252\/cyclones-2-1290x725.png 1290w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182252\/cyclones-2-840x473.png 840w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/29182252\/cyclones-2-410x230.png 410w\" sizes=\"(max-width: 872px) 100vw, 872px\" \/><\/p>\r\n<h2><span style=\"font-weight: 400\">Cyclones Type Based on Location<\/span><\/h2>\r\n<p><span style=\"font-weight: 400\">Cyclones can be broadly classified into tropical and extratropical systems, with subtropical as an intermediate category, based on where they form.<\/span><\/p>\r\n<h3><span style=\"font-weight: 400\">Tropical cyclones<\/span><\/h3>\r\n<p><span style=\"font-weight: 400\">Tropical cyclones form over warm tropical or subtropical oceans. They are typically warm-core systems that derive their energy mainly from ocean heat and the latent heat released when water vapour condenses.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Location:<\/b><span style=\"font-weight: 400\"> Typically found in warm tropical and subtropical ocean basins.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Structure:<\/b><span style=\"font-weight: 400\"> Usually have a compact, rotating low-pressure centre. In more mature systems, an eye and eyewall may form.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Weather:<\/b><span style=\"font-weight: 400\"> These systems bring strong winds, heavy rainfall, thunderstorms, and near-coastal storm surges that can be extremely destructive.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Energy source:<\/b><span style=\"font-weight: 400\"> Their energy comes from the heat and moisture provided by the ocean, along with latent heat released during condensation.<\/span><\/li>\r\n<\/ul>\r\n<h3><span style=\"font-weight: 400\">Temperate or extratropical cyclone<\/span><\/h3>\r\n<p><span style=\"font-weight: 400\">Temperate or extratropical cyclones form mainly in the middle latitudes, where air masses with different temperatures meet. They are linked with weather fronts and get a lot of their energy from differences in temperature across horizontal areas.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Location:<\/b><span style=\"font-weight: 400\"> They are mostly found in mid-latitudes, especially in areas where there are sharp contrasts between different types of air.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Structure:<\/b><span style=\"font-weight: 400\"> These systems usually include both warm and cold fronts; they rarely have a well-defined eye like tropical cyclones.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Weather:<\/b><span style=\"font-weight: 400\"> They bring cloud lines, changing wind directions, widespread rain, and weather that changes with the front.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Movement:<\/b><span style=\"font-weight: 400\"> They are typically influenced by the main westerly winds and the broader patterns of air movement in the atmosphere.<\/span><\/li>\r\n<\/ul>\r\n<h3><span style=\"font-weight: 400\">Subtropical cyclones<\/span><\/h3>\r\n<p><span style=\"font-weight: 400\">Subtropical cyclones have features of both tropical and extratropical storms. They usually form over subtropical seas and can change into either tropical or extratropical systems as their structure and the surrounding weather conditions evolve.<\/span><\/p>\r\n<h2><span style=\"font-weight: 400\">Cyclones Type Based on Speed of the Cyclone<\/span><\/h2>\r\n<p><span style=\"font-weight: 400\">Cyclones are grouped into different categories depending on how fast the winds are blowing. These categories are based on the kind of damage they can cause.<\/span><\/p>\r\n<table style=\"width: 96.2923%\">\r\n<tbody>\r\n<tr>\r\n<td class=\"tb-color\" style=\"width: 26.2525%\"><b>Cyclone Category<\/b><\/td>\r\n<td class=\"tb-color\" style=\"width: 17.5351%\"><b>Wind Speed in km\/h<\/b><\/td>\r\n<td class=\"tb-color\" style=\"width: 51.6032%\"><b>Damage Capacity<\/b><\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 26.2525%\">\r\n<p><span style=\"font-weight: 400\">Low Pressure Area<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 17.5351%\">\r\n<p><span style=\"font-weight: 400\">Less than 31<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 51.6032%\">\r\n<p><span style=\"font-weight: 400\">Negligible \/ None<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 26.2525%\">\r\n<p><span style=\"font-weight: 400\">Depression (D)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 17.5351%\">\r\n<p><span style=\"font-weight: 400\">31-49<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 51.6032%\">\r\n<p><span style=\"font-weight: 400\">Negligible\/minor localised showers<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 26.2525%\">\r\n<p><span style=\"font-weight: 400\">Deep Depression (DD)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 17.5351%\">\r\n<p><span style=\"font-weight: 400\">50-61<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 51.6032%\">\r\n<p><span style=\"font-weight: 400\">Minor damage to loose structures, rough seas<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 26.2525%\">\r\n<p><span style=\"font-weight: 400\">Cyclonic Storm (CS)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 17.5351%\">\r\n<p><span style=\"font-weight: 400\">62-88<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 51.6032%\">\r\n<p><span style=\"font-weight: 400\">Light to moderate damage; thatch roofs damaged, tree branches broken<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 26.2525%\">\r\n<p><span style=\"font-weight: 400\">Severe Cyclonic Storm (SCS)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 17.5351%\">\r\n<p><span style=\"font-weight: 400\">89-117<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 51.6032%\">\r\n<p><span style=\"font-weight: 400\">Moderate to severe damage; trees uprooted, pucca structures minor damage<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 26.2525%\">\r\n<p><span style=\"font-weight: 400\">Very Severe Cyclonic Storm (VSCS)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 17.5351%\">\r\n<p><span style=\"font-weight: 400\">118-166<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 51.6032%\">\r\n<p><span style=\"font-weight: 400\">Extensive damage; extensive roof\/tree damage, disruption of power\/communication<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 26.2525%\">\r\n<p><span style=\"font-weight: 400\">Extremely Severe Cyclonic Storm (ESCS)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 17.5351%\">\r\n<p><span style=\"font-weight: 400\">167-221<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 51.6032%\">\r\n<p><span style=\"font-weight: 400\">Extensive to catastrophic damage; large structures compromised, major flooding<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 26.2525%\">\r\n<p><span style=\"font-weight: 400\">Super Cyclonic Storm (SuCS)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 17.5351%\">\r\n<p><span style=\"font-weight: 400\">More than or equal to 222<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 51.6032%\">\r\n<p><span style=\"font-weight: 400\">Total devastation \/ catastrophic destruction<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<h2><img decoding=\"async\" class=\"wp-image-31502 aligncenter\" src=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/30020800\/cyclones-3.png\" alt=\"Cyclones\" width=\"789\" height=\"604\" srcset=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/30020800\/cyclones-3.png 1433w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/30020800\/cyclones-3-768x588.png 768w\" sizes=\"(max-width: 789px) 100vw, 789px\" \/><span style=\"font-weight: 400\">Tropical Cyclones Favourable Conditions<\/span><\/h2>\r\n<p><span style=\"font-weight: 400\">Tropical cyclogenesis requires a combination of warm ocean water, moisture, atmospheric instability, a pre-existing disturbance and favourable wind conditions. The major conditions for tropical cyclone formation are the following:<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Warm ocean water:<\/b><span style=\"font-weight: 400\"> Sea-surface temperatures of around 27\u00b0C or above over a sufficient depth generally provide the heat and moisture needed for development.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>High atmospheric moisture:<\/b><span style=\"font-weight: 400\"> Moist air in the lower and middle troposphere supports deep convection and reduces the disruption caused by dry-air entrainment.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Atmospheric instability:<\/b><span style=\"font-weight: 400\"> Warm, moist air must be able to rise, cool and condense, releasing latent heat that supports further development.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Sufficient Coriolis force:<\/b><span style=\"font-weight: 400\"> Earth's rotation helps organise the circulation. Tropical cyclones rarely form close to the equator because the Coriolis force is too weak there.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Pre-existing low-pressure disturbance:<\/b><span style=\"font-weight: 400\"> A tropical wave or another organised disturbance supplies initial low-level convergence and cyclonic vorticity.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Weak vertical wind shear:<\/b><span style=\"font-weight: 400\"> Limited changes in wind speed and direction with height help maintain vertically aligned convection around the developing centre.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Upper-level outflow:<\/b><span style=\"font-weight: 400\"> Air must be able to spread outward at higher levels, helping sustain rising motion and the pressure fall near the surface.<\/span><\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">Cyclones Formation Mechanism, or Cyclogenesis<\/span><\/h2>\r\n<p><span style=\"font-weight: 400\">Cyclone formation mechanism, or cyclogenesis, refers to the development and intensification of a cyclonic circulation. The process differs between tropical and temperate cyclones because their primary energy sources are different.<\/span><\/p>\r\n<h3><span style=\"font-weight: 400\">Tropical cyclogenesis<\/span><\/h3>\r\n<p><span style=\"font-weight: 400\">Tropical cyclogenesis is driven mainly by heat and moisture from warm oceans and the latent heat released as water vapour condenses. The process involves positive feedback between surface inflow, convection, latent heat release and falling central pressure. Its development can be explained in the following stages.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Initial disturbance:<\/b><span style=\"font-weight: 400\"> A tropical wave or pre-existing low-pressure disturbance creates low-level convergence and organised atmospheric circulation.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Warm, moist air rises:<\/b><span style=\"font-weight: 400\"> Air converges towards the disturbance and rises over the warm ocean, producing deep convective clouds and thunderstorms.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Latent heat is released:<\/b><span style=\"font-weight: 400\"> Water vapour condenses in rising air, releasing latent heat. This warms the atmospheric core and supports further ascent.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Central pressure falls:<\/b><span style=\"font-weight: 400\"> Continued convection and favourable upper-level outflow help remove air from above the system. The pressure gradient strengthens, accelerating near-surface winds.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Rotation becomes organised:<\/b><span style=\"font-weight: 400\"> The Coriolis force helps organise the circulation around the low-pressure centre. Increasing convection and wind speeds allow the disturbance to intensify.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Mature cyclones develop:<\/b><span style=\"font-weight: 400\"> In sufficiently organised and intense systems, an eye may form, surrounded by an eyewall containing the strongest winds and intense rainfall.<\/span><\/li>\r\n<\/ul>\r\n<h3><span style=\"font-weight: 400\">Temperate cyclogenesis<\/span><\/h3>\r\n<p><span style=\"font-weight: 400\">Temperate cyclogenesis is closely associated with the polar front, where relatively warm air and cold polar air meet. A disturbance along this boundary can develop into a wave-like low-pressure system.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Initial disturbance:<\/b><span style=\"font-weight: 400\"> A wave develops along the boundary between contrasting air masses.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Pressure falls:<\/b><span style=\"font-weight: 400\"> Air circulates around the developing low, and the frontal boundary becomes more organised.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Warm and cold fronts develop:<\/b><span style=\"font-weight: 400\"> Warm air advances along the warm front, while colder air pushes forward along the cold front.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Cyclone intensifies:<\/b><span style=\"font-weight: 400\"> Rising air, frontal uplift and the temperature contrast between air masses produce widespread cloud, precipitation and changing weather.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Occlusion and weakening:<\/b><span style=\"font-weight: 400\"> The faster-moving cold front may overtake the warm front, lifting the warm sector from the surface. As the system loses access to its strongest temperature contrast, it generally weakens.<\/span><\/li>\r\n<\/ul>\r\n<h3><span style=\"font-weight: 400\">Reasons for More Cyclones in the Bay of Bengal<\/span><\/h3>\r\n<p><span style=\"font-weight: 400\">Between 1891 and 2025, the Bay of Bengal recorded nearly four times more tropical cyclones than the Arabian Sea. These cyclones are relatively more intense due to favourable conditions like warmer sea temperatures, higher humidity, and conducive wind patterns.<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Geographical features:<\/b><span style=\"font-weight: 400\"> The Bay of Bengal is shaped like a trough, which makes it more conducive for storms to gain force.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Warm water: <\/b><span style=\"font-weight: 400\">The Bay of Bengal has warmer and higher sea surface temperatures than the Arabian Sea. Warm water provides the necessary energy for cyclones to form and intensify.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Oceanic conditions:<\/b><span style=\"font-weight: 400\"> The upper ocean layer in the Bay of Bengal is very shallow, making sea surface temperatures (SST) spike rapidly in response to daily solar heating and monsoonal air fluxes.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Freshwater Barrier Layer:<\/b><span style=\"font-weight: 400\"> Massive freshwater inflows from rivers like the Ganga, Brahmaputra, and Godavari create a buoyant, low-salinity layer at the surface (the \"barrier layer\").<\/span>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">This strong density and salinity stratification prevents cooler deep water from mixing upward and stops warmer subsurface water from freely turning over.<\/span><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li style=\"font-weight: 400\"><b>Trapped Subsurface Heat:<\/b><span style=\"font-weight: 400\"> Instead of uniformly releasing heat to the atmosphere, the stratification traps thermal energy in subsurface layers.<\/span>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">This can delay immediate surface heat release during cooling phases or winter, though high surface temperatures (29\u00b0C\u201331\u00b0C) still fuel intense evaporation and tropical cyclones when atmospheric conditions align.<\/span><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li style=\"font-weight: 400\"><b>Arabian Sea Conditions:<\/b><span style=\"font-weight: 400\"> On the other hand, the lack of constant fresh water in the Arabian Sea helps the warm water to mix with the cool water underneath, reducing the surface temperature.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Landmass:<\/b><span style=\"font-weight: 400\"> Lack of landmass between the Pacific Ocean and the Bay of Bengal causes cyclonic winds to move into the coastal areas, causing heavy rainfall.\u00a0<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Air movement:<\/b><span style=\"font-weight: 400\"> The absence of air movement from northwestern India towards the Bay of Bengal in the post-monsoon phase is also another reason for the chances of cyclones in the Bay of Bengal.<\/span><\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">Cyclones in India<\/span><\/h2>\r\n<p><span style=\"font-weight: 400\">Throughout history, India has experienced some of the deadliest cyclones, each leaving a lasting impact on the affected communities. The following are a few of the recent historically destructive cyclones:<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Cyclone Arnab (2026):<\/b><span style=\"font-weight: 400\"> A Very Severe Cyclonic Storm that crossed the Andhra Pradesh and Yanam coasts between Bapatla and Visakhapatnam on 28 October 2026, near Narsapur, with sustained winds of 125-135 km\/h and gusts up to 150 km\/h.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Cyclone Montha (2025):<\/b><span style=\"font-weight: 400\"> A Severe Cyclonic Storm that crossed the Andhra Pradesh coast in October 2025, bringing heavy rainfall and flooding risks to Andhra Pradesh and neighbouring regions.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Cyclone Shakhti (2025):<\/b><span style=\"font-weight: 400\"> A Severe Cyclonic Storm over the Arabian Sea from 1-7 October 2025. It dissipated over the sea without making landfall, making it an important recent example of a strong Arabian Sea cyclone that did not directly cross the Indian coast.<\/span><\/li>\r\n<\/ul>\r\n<h4><span style=\"font-weight: 400\">Other Cyclones<\/span><\/h4>\r\n<table style=\"width: 88.8445%\">\r\n<tbody>\r\n<tr>\r\n<td class=\"tb-color\" style=\"width: 22.2955%\"><b>Cyclone Name (Year)<\/b><\/td>\r\n<td class=\"tb-color\" style=\"width: 93.472%\"><b>Most Affected Areas<\/b><\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Fengal (2024)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Tamil Nadu, Puducherry<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Dana (2024)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Odisha, West Bengal<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Remal (2024)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Coastal West Bengal, Sundarbans, Bangladesh<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Asna (2024)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Gujarat and the Arabian Sea; developed over land before moving over the sea<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Michaung (2023)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Andhra Pradesh, Tamil Nadu (particularly Chennai due to flooding)<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Biparjoy (2023)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Gujarat (Kutch and Saurashtra), parts of Pakistan<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Mandous (2022)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">North Tamil Nadu, Puducherry<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Tauktae (2021)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Gujarat, Maharashtra, Goa, Karnataka, Kerala<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Yaas (2021)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Odisha, West Bengal<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Amphan (2020)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">West Bengal (Kolkata and Sundarbans), Bangladesh<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Nisarga (2020)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Maharashtra (Alibag, Mumbai region)<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Fani (2019)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Odisha (particularly Puri and adjoining coastal districts)<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Gaja (2018)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Tamil Nadu (particularly the Cauvery delta and Nagapattinam)<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<tr>\r\n<td style=\"width: 22.2955%\">\r\n<p><span style=\"font-weight: 400\">Ockhi (2017)<\/span><\/p>\r\n<\/td>\r\n<td style=\"width: 93.472%\">\r\n<p><span style=\"font-weight: 400\">Kerala, Tamil Nadu, Lakshadweep<\/span><\/p>\r\n<\/td>\r\n<\/tr>\r\n<\/tbody>\r\n<\/table>\r\n<h2><span style=\"font-weight: 400\">India\u2019s Vulnerability To Cyclones<\/span><\/h2>\r\n<p><span style=\"font-weight: 400\">India is highly vulnerable to natural hazards, particularly cyclones, floods, earthquakes, drought and landslides.\u00a0<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">India's 11,098.81 km-long coastline, extensive low-lying coastal plains, shallow continental shelves in vulnerable regions, and dense coastal settlements increase its exposure to tropical cyclones, storm surges and coastal flooding.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Its geographical and physical features further intensify associated hazards such as storm tides, high-velocity winds, and heavy rainfall.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Nearly about 8% of the country\u2019s geographical area of India\u2019s coastline, spanning 84 coastal districts across 13 states and Union Territories, faces recurrent impacts from severe tropical cyclones each year.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Around 40% of India\u2019s population lives within 100 km of the coastline, making them highly vulnerable to cyclones.<\/span><\/li>\r\n<\/ul>\r\n<p><img decoding=\"async\" class=\"size-full wp-image-31506 aligncenter\" src=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/30103411\/cyclone-5.png\" alt=\"Cyclones\" width=\"846\" height=\"675\" srcset=\"https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/30103411\/cyclone-5.png 846w, https:\/\/vajiramias.sgp1.cdn.digitaloceanspaces.com\/wp\/upsc-exam\/2026\/10\/30103411\/cyclone-5-768x613.png 768w\" sizes=\"(max-width: 846px) 100vw, 846px\" \/><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Though the frequency of Tropical Cyclones (TCs) in the North Indian Ocean (NIO), covering the Bay of Bengal and the Arabian Sea, is the lowest in the world (7% of the global total \u2192 3 to 4 make landfall out of 5 to 6 tropical cyclones annually), their impact on the east coast of India is relatively more devastating due to the storm tidal effect in the area.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Climate change is a major challenge for developing nations like India, threatening to enhance risks already elevated by high levels of social vulnerability and climate variability.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">Climate change is increasing the risks associated with tropical cyclones through rising sea levels, heavier cyclone-related rainfall and the potential for more intense storms. However, changes in overall cyclone frequency remain uncertain and vary across regions.<\/span><\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">Cyclones Impacts and Hazards<\/span><\/h2>\r\n<p><span style=\"font-weight: 400\">Cyclones can devastate coastal and inland areas, presenting various hazards that require comprehensive disaster management strategies. Some of the primary hazards associated include:<\/span><\/p>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><b>Strong winds: <\/b><span style=\"font-weight: 400\">Cyclones are characterised by powerful winds that can cause extensive damage to infrastructure, buildings, and vegetation. High-speed winds can uproot trees, damage power lines, and create hazardous flying debris.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Storm surges:<\/b><span style=\"font-weight: 400\"> Cyclones in coastal areas often bring storm surges and abnormal sea level rises. This can result in coastal flooding, submerging low-lying areas, damaging coastal infrastructure, and leading to the displacement of communities.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Heavy rainfall and flooding: <\/b><span style=\"font-weight: 400\">Rainfall associated with tropical cyclones is both beneficial and harmful. Although the rains contribute to the water needs of the areas traversed by the cyclones, the rains are harmful when the amount is so large as to cause flooding.<\/span><\/li>\r\n\t<li style=\"font-weight: 400\"><b>Economic loss:<\/b><span style=\"font-weight: 400\"> Cyclones can devastate crops, including rice, vegetables, and fruits. This can lead to food shortages, loss of income for farmers, and increased food prices.<\/span>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">According to the State of Global Climate Report (2020), Cyclone Amphan led to economic losses in India of approximately $14 billion.<\/span><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li style=\"font-weight: 400\"><b>Human casualties and injuries:<\/b><span style=\"font-weight: 400\"> Cyclones pose risks to human life, with the potential for injuries and fatalities due to collapsing structures, flying debris, drowning, or electrocution.<\/span>\r\n<ul>\r\n\t<li style=\"font-weight: 400\"><span style=\"font-weight: 400\">India faced 40,000 human deaths due to cyclones from 1970 to 2019.<\/span><\/li>\r\n<\/ul>\r\n<\/li>\r\n\t<li style=\"font-weight: 400\"><b>Landslides: <\/b><span style=\"font-weight: 400\">In hilly or mountainous regions, cyclones can trigger landslides due to <\/span><b>excessive rainfall and soil saturation.<\/b><span style=\"font-weight: 400\"> Landslides can bury homes, roads, and communities, causing loss of life and infrastructure damage.<\/span><\/li>\r\n<\/ul>\r\n<h2><span style=\"font-weight: 400\">Cyclones UPSC PYQs<\/span><\/h2>\r\n<p><b>Q1: <\/b><span style=\"font-weight: 400\">What is the Fujiwhara effect? Explain its impact on the movement and intensity of tropical cyclones. <\/span><b>(UPSC Mains 2026)<\/b><\/p>\r\n<p><b>Q2: <\/b><span style=\"font-weight: 400\">Discuss the meaning of colour-coded weather warnings for cyclone prone areas given by India Meteorological Department. <\/span><b>(UPSC Mains 2022)<\/b><\/p>\r\n<p><b>Q3: <\/b><span style=\"font-weight: 400\">Tropical cyclones are largely confined to the South China Sea, Bay of Bengal and Gulf of Mexico. Why?<\/span><b> (UPSC Mains 2014)<\/b><\/p>\r\n<p><b>Q4: <\/b><span style=\"font-weight: 400\">The recent cyclone on the east coast of India was called \u201cPhailin\u201d. How are the tropical cyclones named across the world? Elaborate.<\/span><b> (UPSC Mains 2013)<\/b><\/p>\r\n<p><b>Q5: <\/b><span style=\"font-weight: 400\">Consider the following statements:\u00a0<\/span><\/p>\r\n<ol>\r\n\t<li><span style=\"font-weight: 400\"> Jet streams occur in the Northern Hemisphere only.<\/span><\/li>\r\n\t<li><span style=\"font-weight: 400\"> Only some cyclones develop an eye.<\/span><\/li>\r\n\t<li><span style=\"font-weight: 400\"> The temperature inside the eye of a cyclone is nearly 10\u00baC lesser than that of the surroundings.<\/span><\/li>\r\n<\/ol>\r\n<p><span style=\"font-weight: 400\">Which of the statements given above is\/are correct? <\/span><b>(UPSC Prelims 2020)<\/b><\/p>\r\n<p><span style=\"font-weight: 400\">(a) 1 only<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">(b) 2 and 3 only<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">(c) 2 only<\/span><\/p>\r\n<p><span style=\"font-weight: 400\">(d) 1 and 3 only<\/span><\/p>\r\n<p><b>Ans: (c)<\/b><\/p>","protected":false},"excerpt":{"rendered":"<p>Cyclones are large revolving tropical storms caused by winds blowing around a central area of low atmospheric pressure. Read about its types, mechanism, and impacts.<\/p>\n","protected":false},"author":35,"featured_media":31547,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[38,24],"tags":[2170,40,620],"class_list":["post-31468","post","type-post","status-publish","format-standard","has-post-thumbnail","category-upsc-notes","category-upsc-geography-notes","tag-cyclones","tag-quest","tag-upsc-geography-notes"],"acf":[],"_links":{"self":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/31468","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/users\/35"}],"replies":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/comments?post=31468"}],"version-history":[{"count":9,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/31468\/revisions"}],"predecessor-version":[{"id":31553,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/posts\/31468\/revisions\/31553"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media\/31547"}],"wp:attachment":[{"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/media?parent=31468"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/categories?post=31468"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/vajiramandravi.com\/upsc-exam\/wp-json\/wp\/v2\/tags?post=31468"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}