In this article, You will read Tropical Cyclone, favorable Conditions for Formation, Stages of Formation, Structure, and Characteristics of Tropical Cyclone for UPSC IAS (Geography Notes).
A tropical cyclone is a weather phenomenon that is essentially a rapidly rotating storm system with characteristics such as a low-pressure center, strong winds and thunderstorms that produce heavy rain, among others.
Tropical cyclones are violent storms that originate over oceans intropical areasand move over to the coastal areas bringing about large-scale destruction due to violent winds (squalls), very heavy rainfall (torrential rainfall), andstorm surge.
They are irregular wind movements involvingthe closed circulationof air around a low-pressure center. This closed air circulation (whirling motion) is a result ofrapid upward movement of the hot airwhich is subjected toCoriolis force. The low pressure at the center is responsible for the wind speeds.
Squall – a sudden violent gust of wind or localized storm, especially one bringing rain, snow, or sleet.(Video) Tropical Cyclone | Indian Geography for UPSC CSE/ IAS | Unacademy UPSC | Sumit Rathi
Torrent – a strong and fast-moving stream of water or other liquid.
- The cyclonic wind movements areanti-clockwise in the northern hemisphereandclockwise in the southern hemisphere(This is due toCoriolis force).
- The cyclones are often characterized by the existence of an anticyclone between two cyclones.
- Tropical cyclones occur around the equator at 5 ° – 30 °, but also have varying names depending upon where in the world they form.
- An average tropical cyclone can travel about 300 to 400 miles a day, or about 3,000 miles before it dies out.
Conditions Favorable for Tropical Cyclone Formation
- Large sea surface with a temperature higher than27° C,
- Presence of the Coriolis force enough to create a cyclonic vortex,
- Small variations in the vertical wind speed,
- A pre-existing weak low-pressure area or low-level-cyclonic circulation,
- Upper divergence above the sea level system,
Good Source of Latent Heat
- Ocean waters having temperatures of 27° C or more is the source of moisture that feeds the storm. The condensation of moisture releases enoughlatent heat of condensationto drive the storm.
- The depth of warm water(26-27°C)should extend for60-70 mfrom the surface of the ocean/sea, so that deep convection currents within the water do not churn and mix the cooler water below with the warmer water near the surface.
- The above condition occurs only in western tropical oceans because of warm ocean currents (easterly trade winds push ocean waters towards the west) that flow from the east towards the west forming a thick layer of water with temperatures greater than 27°C. This supplies enough moisture to the storm.
- Thecold currentslower the surface temperatures of the eastern parts of the tropical oceans making them unfit for the breeding of cyclonic storms.
Coriolis Force (f)
- TheCoriolis forceis zero at the equator(no cyclones at the equator because of zero Coriolis Force)but it increases with latitude. Coriolis force at5°latitude is significant enough to create a storm [cyclonic vortex].
- About 65 percent of cyclonic activity occurs between 10° and 20° latitude.
- Low-level disturbance (thunderstorms – they are the seeds of cyclones) in the form of easterly wave disturbances in the Inter-Tropical Convergence Zone (ITCZ) should pre-exist.
- Small local differencesin the temperature of the water and of air produce variouslow-pressure centersof small size. A weak cyclonic circulation develops around these areas.
- Then, because of the rising warm humid air, a true cyclonic vortex may develop very rapidly. However, only a few of these disturbances develop into cyclones.
[rising of humid air => adiabatic lapse rate => fall in temperature of air => condensation of moisture in air => latent heat of condensation released => air gets more hot and lighter => air is further uplifted => more air comes in to fill the gap => new moisture available for condensation => latent heat of condensation and the cycle repeats]
Temperature contrast between air masses
- Trade winds from both hemispheres meet along the inter-tropical front. Temperature contrasts between these air masses must exist when the ITCZ is farthest, from the equator.
- Thus, the convergence of these air masses of different temperatures and the resulting instability are the prerequisites for the origin and growth of violent tropical storms.
Upper Air Disturbance
- The remains of an upper tropospheric cyclone from the Westerlies move deep into the tropical latitude regions. As divergence prevails on the eastern side of the troughs, a rising motion occurs; this leads to the development of thunderstorms.
- Further, these old abandoned troughs (remnants of temperate cyclones) usually have cold cores, suggesting that the environmental lapse rate is steeper and unstable below these troughs. Such instability encourages thunderstorms (child cyclones).
- Wind Shear – differences between wind speeds at different heights.
- Tropical cyclones develop when the wind is uniform.
- Because of weak vertical wind shear, cyclone formation processes are limited to latitude equatorward of thesubtropical jet stream.
- In the temperate regions, wind shear is high due to westerlies and this inhibits convective cyclone formation.
Upper Tropospheric Divergence
- A well – developed divergence in the upper layers of the atmosphere is necessary so that the rising air currents within the cyclone continue to be pumped out and a low pressure maintained at the center.
- High humidity (around 50 to 60 percent) is required in the mid-troposphere since the presence of moist air leads to the formation ofcumulonimbus clouds.
- Such conditions exist over the equatorialdoldrums, especially in western margins of oceans (this is because of the east to west movement of ocean currents), which have great moisture, carrying capacity because thetrade winds continuously replace the saturated air.
Origin and Development of Tropical Cyclones
- The tropical cyclones have athermal origin, and they develop over tropical seas during late summers (August to mid-November).
- At these locations, the strong local convectional currents acquire a whirling motion because of the Coriolis force.
- After developing, these cyclones advance till they find a weak spot in the trade wind belt.
- Under favorable conditions, multiple thunderstorms originate over the oceans. These thunderstorms merge and create an intense low pressure system (wind is warm and lighter).
- In the thunderstorm, the air is uplifted as it iswarm and light. At a certain height, due tolapse rate and adiabatic lapse rate, the temperature of the air falls and moisture in the air undergoescondensation.
- Condensation releaseslatent heat of condensationmaking the air warmer. It becomes much lighter and is further uplifted.
- Space is filled with fresh moisture-laden air. Condensation occurs in this air and the cycle is repeated as long as the moisture is supplied.
- Due to excess moisture over oceans, the thunderstorm intensifies and sucks in the air at a much faster rate. The air from surroundings rushes in and undergoes deflection due toCoriolis forcecreating acyclonic vortex (spiraling air column. Similar toa tornado).
- Due to centripetal acceleration (centripetal force pulling towards the center is countered by an opposing force called the centrifugal force), the air in the vortex is forced to form a region of calmness called aneyeat the center of the cyclone. The inner surface of the vortex forms theeyewall, themost violent regionof the cyclone.
[Eye is created due to tangential force acting on wind that is following a curvy path]
- All the wind that is carried upwards loses its moisture and becomes cold and dense. It descends to the surface through the cylindrical eye region and at the edges of the cyclone.
- Continuous supply ofmoisturefrom the sea is the major driving force behind every cyclone. On reaching the land themoisture supply is cut offand the storm dissipates.
- If ocean can supply more moisture, the storm will reach a mature stage.
- At this stage, the spiraling winds create multiple convective cells with successive calm and violent regions.
- The regions with cumulonimbus cloud (rising limbs of the convective cell) formation are calledrain bandsbelow which intense rainfall occurs.
- The ascending air will lose moisture at some point and descends (subsides) back to the surface through the calm regions (descending limbs of convection cell – subsiding air) that exist between two rain bands.
- Cloud formation is dense at the center. The cloud size decreases from center to periphery.
- Rain bands are mostly made up of cumulonimbus clouds. The ones at the periphery are made up of nimbostratus and cumulus clouds.
- The dense overcast at the upper levels of the troposphere is due tocirrus cloudswhich are mostly made up of hexagonal ice crystals.
- The dry air flowing along the central dense overcast descends at the periphery and the eye region.
Structure of a tropical cyclone
- A mature tropical cyclone is characterized by the strong spirally circulating wind around the centre which is called the eye.
- The “eye” is a roughly circular area of comparativelylight winds, clear skies. and fair weatherfound at the center of a severe tropical cyclone.
- There is little orno precipitationand sometimes blue sky or stars can be seen.
- The eye is the region oflowest surface pressureand warmest temperatures aloft (in the upper levels) – the eye temperature may be 10°C warmer or more at an altitude of 12 km than the surroundingenvironment, but only 0-2°C warmer at the surface in the tropical cyclone.
- Eyes range in size from 8 km to over 200 km across, but most are approximately 30-60 km in diameter.
- The eye is surrounded by the “eyewall”, the roughly circular ring ofdeep convection, which is the area ofhighest surface windsin the tropical cyclone. The Eye Wall region also sees the maximum sustained winds i.e.fastest winds in a cyclone occur along the eyewall region.
- The eye is composed of air that is slowly sinking and the eyewall has a net upward flow as a result of many moderate – occasionally strong
- The eye’s warm temperatures are due to compressional warming (adiabatic) of the subsiding air.
- Most soundings taken within the eye show a low-level layer, which is relatively moist, with an inversion above – suggesting that the sinking in the eyetypically does not reach the ocean surface, but instead only gets to around 1-3 km of the surface.
- The wind reaches maximum velocity in this region and torrential rain occurs here.
- From the eyewall, rain bands may radiate and trains of cumulus and cumulonimbus clouds may drift into the outer region.
- Another feature of tropical cyclones that probably plays a role informing and maintaining the eyeis the eyewall convection.
- Convection in tropical cyclones is organized into long, narrow rain bands which are oriented in the same direction as the horizontal wind.
- Because these bandsseem to spiral into the centerof a tropical cyclone, they are called “spiral bands”.
- Along with these bands, low-level convergence is a maximum, and therefore, upper-level divergence is most pronounced above.
- A direct circulation develops in which warm, moist air converges at the surface, ascends through these bands,diverges aloft, anddescends on both sides of the bands.
- Subsidence is distributed over a wide area on the outside of the rain band but is concentrated in the small inside area.
- As the air subsides, adiabatic warming takes place, and the air dries.
- Because subsidence is concentrated on the inside of the band, the adiabatic warming is stronger inward from the band causing a sharp contrast in pressure to fall across the band since warm air is lighter than cold air.
- Because the pressure falls on the inside, the tangential winds around the tropical cyclone increase due to the increased pressure gradient. Eventually, the band moves toward the center and encircles it, and theeye and eye wall form.
- Thus, the cloud-free eye may be due to acombination of dynamically forced centrifuging of mass out of the eye into the eyewall and to a forced descent caused by the moist convection of the eyewall.
Vertical Structure of a Tropical Cyclone
There are three divisions in the vertical structure of tropical cyclones.
- The lowest layer, extending up to 3 km and known as the inflow layer, is responsible fordriving the storm.
- The middle layer, extending from 3 km to 7 km, is where themain cyclonic stormtakes place.
- The outflow layer lies above 7 km. The maximum outflow is found at 12 km and above. The movement of air isanticyclonicin nature.
Categories of Tropical Cyclones
This is the tropical cyclone category system as used by theBureau of Meteorology:
- Category one (tropical cyclone): A category one cyclone’s strongest winds are GALES with typical gusts over open flat land of 90-125kph,
- Category two (tropical cyclone): A category two cyclone’s strongest winds are DESTRUCTIVE winds with typical gusts over open flat land of 125-164kph,
- Category three (severe tropical cyclone): A category three cyclone’s strongest winds are VERY DESTRUCTIVE winds with typical gusts over open flat land of 165-224kph,
- Category four (severe tropical cyclone): A category four cyclone’s strongest winds are VERY DESTRUCTIVE winds with typical gusts over open flat land of 225-279kph,
- Category five (severe tropical cyclone): A category five cyclone’s strongest winds are VERY DESTRUCTIVE winds with typical gusts over open flat land of more than 280kph.
Favorite Breeding Grounds for Tropical Cyclones
- South-east Caribbean region where they are called hurricanes.
- Philippines islands, eastern China, and Japan where they are called typhoons.
- The Bay of Bengal and the Arabian Sea where they are called cyclones.
- Around the south-east African coast and Madagascar-Mauritius islands.
- North-west Australia.
Regional names for Tropical Cyclones
|Regions||What they are called|
|Western Pacific and South China Sea||Typhoons|
Characteristics of Tropical Cyclones
The main features of tropical cyclones are as follows.
Size and Shape
- Tropical cyclones have symmetricalelliptical shapes(2:3 ratio of length and breadth) with steep pressure gradients. They have a compact size—80 km near center, which may develop up to 300 km to 1500 km.
Wind Velocity and Strength
- Wind velocity, in a tropical cyclone, is more in poleward margins than at center and is moreover oceans than over landmasses, which are scattered with physical barriers. The wind velocity may range from nil to 1200 km per hour.
Path of Tropical Cyclones
- These cyclones start with a westward movement but turn northwards around 20° latitude. They turn further north-eastwards around 25° latitude, and then eastwards around 30° latitude. They then lose energy and subside.
- Tropical cyclones follow aparabolic path, their axis being parallel to the isobars.
- Coriolis force or earth’s rotation, easterly and westerly winds influence the path of a tropical cyclone.
- Tropical cyclones die at 30° latitude because of cool ocean waters and increasing wind shear due to westerlies.
Warning of Tropical Cyclones
- Detection of any unusual phenomena in the weather leading to cyclones has three main parameters:fall in pressure, increase in wind velocity, and the direction and movement (track) of the storm.
- There is a network of weather stations monitoring pressure fall and wind velocities in all countries of the world, including the Arctic and Antarctic regions.
- The islands attain special significance in this as they facilitate monitoring of these developments.
- In India, there are detection radars along both coasts.
- Monitoring is also done by aircraft which carry a number of instruments including weather radar.
- Cyclone monitoring by satellites is done through very high-resolution radiometers, working in the visual and infra-red regions (for night view) of the spectrum to obtain an image of the cloud cover and its structure.
- Remote sensing by radars, aircraft, and satellites helps predict where exactly the cyclone is going to strike. It helps in taking advanced steps in the following areas:
- closing of ports and harbors,
- suspension of fishing activities,
- evacuation of the population,
- stocking of food and drinking water, and
- provision of shelter with sanitation facilities (safety homes).
- Today, it is possible to detect a cyclone right from its genesis in the high seas and follow its course, giving a warning at least 48 hours prior to a cyclone strike.
- However, the predictions of a storm course made only 12 hours in advance do not have a very high rate of precision.
Major Differences between Temperate Cyclone and Tropical Cyclone
|Tropical Cyclone||Temperate Cyclone|
|tropical cyclones, move from east to west.||These cyclones move from west to east|
|A tropical cyclone has an effect on a comparatively smaller area than a Temperate cyclone.||Temperate cyclone affect a much larger area|
|The velocity of wind in a tropical cyclone is much higher and it is more damaging.||The velocity of air is comparatively lower|
|Tropical Cyclone forms only on seas with temperature more than 26-27degree C and dissipate on reaching the land.||Temperate cyclones can be formed on both land and sea|
|A tropical cyclone doesn’t last for more than 7 days||Temperate cyclone can last for a duration of 15 to 20 days|
A tornado is a violently rotating column of air that extends from a thunderstorm to the ground. It is a vortex of rapidly moving air. A tornado forms when changes in wind speed and direction create a horizontal spinning effect within a storm cell. This effect is then tipped vertically by rising air moving up through the thunderclouds.
- Winds within the tornado funnel may exceed 500kmph.
- High-velocity winds cause most of the damage associated with these weather events.
- Tornadoes also cause damage through air pressure reductions.
- The air pressure at the tornado centre is approximately 800 millibars (average sea-level pressure is 1013 millibars) and many human-made structures collapse outward when subject to pressure drops of this magnitude.
Origin of Tornado
- Tornado formation typically needs four ingredients: shear, lift, instability, and moisture.
- Wind shear is the most important factor that plays into the creation of tornadoes. When there is wind shear, sometimes these winds begin to roll into a horizontal column of air.
- Once you get a strong updraft of air being transported from the ground to the atmosphere, that column of air becomes vertical. That is when a storm usually develops in this scenario.
- As the storm develops, it turns into a supercell thunderstorm much of the time. These supercell thunderstorms are separate, discrete cells that are not part of a line of storms. Also, supercells are storms that rotate and spin. With both the vertical, rotating column of air and the supercell thunderstorm together, that may bring down a tornado from the storm cloud
- Tornadoes are most common in spring and least common in winter. Spring and fall experience peaks of activity as those are the seasons when stronger winds, wind shear, and atmospheric instability are present. Tornado occurrence is highly dependent on the time of day, because of solar heating.
Distribution of tornadoes
- Rare in polar regions and infrequent at latitudes higher than 50° N and 50° S.
- The temperate and tropical regions are the most prone to thunderstorms.
- Tornadoes have been reported on all continents except Antarctica.
- The United States has the most violent tornadoes.
- Canada reports the second largest number of tornadoes.
- In the Indian sub-continent, Bangladesh is the most prone country to tornadoes.
- At any moment there are approximately 1,800 thunderstorms in progress throughout the world.
Differences between Tornado and cyclone
|Definition||A tornado is a rotating column of air ranging in width from a few yards to more than a mile and whirling at destructively high speeds, usually accompanied by a funnel-shaped downward extension of a cumulonimbus cloud. Winds 40-300+ mph.||A cyclone is an atmospheric system of rapidly circulating air massed about a low-pressure centre, usually accompanied by stormy often destructive weather. Storms that begin in the Southern Pacific are called cyclones|
|Rotation||Clockwise in the southern hemisphere and counter clockwise in the northern hemisphere||Clockwise in the southern hemisphere and counter clockwise in the northern hemisphere.|
|Forms of precipitation||rain||Rain, sleet, and hail|
|Frequency||The United States records about 1200 tornadoes per year, whereas the Netherlands records the highest number of tornadoes per area compared to other countries. Tornadoes occur commonly in spring and the fall season and are less common in winters||10-14 per year|
|Location||Tornados have been spotted in all continents except Antarctica||Southern Pacific Ocean, Indian Ocean. Cyclones in the northwest Pacific that reach (exceed) 74 mph are “typhoons”.|
|Occurrence||Places where cold and warm fronts converge. Can be just almost anywhere.||warm areas|
Tornadoes, as well as cyclones both, occur in India. However, unlike cyclones, the frequency of tornado outbreaks is very low. Cyclones originate in the Bay of Bengal region as well as in the Arabian Sea region whereas Tornadoes of weak strength occur in the north-western and north-eastern region of the country causing significant damage to man and material.
A tropical cyclone brings very violent winds, torrential rain, high waves and, in some cases, very destructive storm surges and coastal flooding. The winds blow counterclockwise in the Northern Hemisphere and clockwise in the Southern Hemisphere.
Tropical cyclones are formed over warm ocean water near the equator. Warm moist air near the surface of the ocean rises upwards. This creates a low-pressure area near the surface. This results in the movement of cooler air from surrounding areas into the low-pressure area.
Tropical cyclones are compact, circular winds with a diameter of 320km. Its winds swirl around a central region that has low atmospheric pressure. The rotation of the winds is largely driven by the low-pressure centre and by the rotation of the Earth.
Tropical cyclones are warm-core low pressure systems associated with a spiral inflow of mass at the bottom level and spiral outflow at the top level. They always form over oceans where sea surface temperature, also air temperatures are greater than 26°C.
- The average speed is 120 kmph. Although it may vary from 32 kmph to 200 kmph or more. At times it reaches 400 kmph also.
- They have closed isobars. The pressure gradient is very sharp. ...
- Tropical cyclones develop over oceans and seas only. They are most violent and vigorous over water.
- Warm waters, instability, and mid-level moisture.
- Coriolis force.
- Low level disturbance.
- Weak vertical wind shear.
IAS Exam Latest Updates
Low-pressure systems that originate over warm tropical waters are known as tropical cyclones. When the sea surface temperature is over 26.5°C, tropical cyclones form.
Classification. There are two types of cyclones: Tropical cyclones; and. Extra Tropical cyclones (also called Temperate cyclones or middle latitude cyclones or Frontal cyclones or Wave Cyclones).
The development of cycle of tropical cyclones may be divided into three stages. a) Formation and initial development (b) Full maturity (c) Modification or decay!
Tropical cyclones are referred to by different names depending on where they originate in the world. Hurricanes occur in the Atlantic Ocean and the eastern north Pacific Ocean. Typhoons occur in the western Pacific Ocean. Tropical cyclones occur in the south Pacific Ocean and Indian Ocean.
“Tropical cyclone” is the generic term for a low- pressure system over tropical or subtropical waters. with organized convection and a definite cyclonic. surface wind circulation (counter-clockwise in the. Northern Hemisphere and clockwise in the South-
So what are the characteristics of a category 5 tropical cyclone? The bureau describes such a cyclone as being "severe", "extremely dangerous" and causing "widespread destruction". The bureau categorises tropical cyclone intensity according to the maximum mean wind speed over open, flat land or water.
Conditions for the formation of Tropical Cyclone
Large sea surface with a temperature higher than 27° C. Presence of the Coriolis force. Small differences in the vertical wind speed. A pre-existing weak- low-pressure area or low-level-cyclonic circulation (Learn about the atmospheric pressure in the linked article.)
- Warm Ocean Water. Tropical cyclones can only form over ocean surfaces that are at least 27 degrees Celsius warm. ...
- Coriolis Force. Tropical cyclones need to form at least five degrees of latitude away from the equator. ...
- Low Wind Shear.
Tropical Cyclones. Tropical cyclones are violent storms that originate over oceans in tropical areas and move over to the coastal areas bringing about large scale destruction caused by violent winds, very heavy rainfall and storm surges. This is one of the most devastating natural calamities.
NCERT Notes on Tropical Cyclone (Geography) for UPSC IAS Exam preparation. Study the characteristic features of tropical cyclones, formation and decay.
Cyclones which originate over the warm tropical oceans with a speed of approx more than 119 Km/hr and heavy rainfall are called tropical cyclones.. Violent cyclone or storm that originates from the oceans in a tropical area and further they move over to the coastal areas bringing about large scale destruction which is caused by violent high speed winds, very heavy rainfall and storm surges, it is called tropical cyclone.. The Southern Pacific and Indian Ocean serve tropical cyclones.. There are different names given for different regions of cyclones in the world for example: its Typhoons in China Sea and Pacific Ocean, West Indian Island it is known as Hurricanes whereas in Guinea lands of West Africa and southern USA known as Tornados and in Indian ocean it is known as tropical cyclone.. The Origin point of tropical cyclones is the Bay of Bengal, Arabian Sea and the Indian ocean and they accompany very high wind velocity and heavy rainfall and hit the Indian Coastal states of Tamil Nadu, Andhra Pradesh, West Bengal,Odisha and Gujarat.. Ans.3 The Southern Pacific and the Indian Oceans serve tropical cyclones.
Tropical Cyclones, Formation, Favorable Conditions, Stages of Formation, Extra Tropical Cyclone UPSC IAS
They occur mainly in the tropical and temperate regions of the world.. Because of high sea temperature (>26.5C), a low pressure is developed over the sea.. Cyclone forming beyond the tropics are called the middle latitude or extra tropical cyclones.. But the if the front is disturbed, temperate cyclone result.. In the northern hemisphere, warm air blows from the south and cold air from the north of the front.. As a result of such motion, the warm air glides over the cold air and a sequence of clouds appear over the sky and cause precipitation.. As a result, cumulus clouds develop along the cold front.. Whereas the tropical cyclones can originate only over the seas and on reaching the land they dissipate.. Tropical cyclones occur in tropical regions except between 5N-5S because of absence of coriolis force.. Cyclones that form over the Bay of Bengal are either those develop insitu over southeast Bay of Bengal and adjoining Andaman Sea or remnants of typhoons over Northwest Pacific and move across south China sea to Indian Seas.. As the majority of cyclones over the Bay of Bengal weaken over land after landfall, the frequency of migration into Arabian Sea is low.. During this rainy season, the low pressure system upto the intensity of depressions form along the monsoon trough, which extends from northwest India to the north Bay of Bengal.
Tropical Cyclones: Favorable Conditions for Formation, Stages of Formation & Structure
Tropical cyclones are violent storms that originate over oceans in tropical areas and move over to the coastal areas bringing about large scale destruction due to violent winds (squalls), very heavy rainfall (torrential rainfall) and storm surge .. [rising of humid air => adiabatic lapse rate => fall in temperature of air => condensation of moisture in air => latent heat of condensation released => air gets more hot and lighter => air is further uplifted => more air comes in to fill the gap => new moisture available for condensation => latent heat of condensation and the cycle repeats]. Due to centripetal acceleration (centripetal force pulling towards the center is countered by an opposing force called centrifugal force), the air in the vortex is forced to form a region of calmness called an eye at the center of the cyclone.. Eye Wall region also sees the maximum sustained winds i.e. fastest winds in a cyclone occur along the eye wall region.. Path of Tropical Cyclones. a) These cyclones start with a westward movement —- This is because the earth is rotating from west to east and the zone of cyclone formation is under the influence of easterlies.
Hurricane Danielle, the first Category 1 storm of the Atlantic Hurricane Season heads closer to Europe this week ›
Danielle, the first hurricane of the Atlantic season 2022, is forecast to become a subtropical storm, gradually turning towards western Europe.
Until Danielle, the first hurricane of the Atlantic season 2022, that has been upgraded from a tropical storm into a hurricane on Sept 2nd.. Thanks to significantly warm oceanic waters between the United States East Coast and the Bay of Biscay, Danielle will be the first tropical cyclone of the Atlantic Hurricane Season that will turn towards the European continent in 2022.. Further west in the western tropical Atlantic there is another tropical storm Earl, the 5th named system in 2022.. When the perfect combination of these is met, it leads to the formation of tropical weather events such as tropical storms or hurricanes, becoming a potential threat to land and property.. On average, the Atlantic hurricane season produces up to 14 named tropical storms every year.. In other words, combined together with a very warm Atlantic they allow tropical storms or hurricanes to develop.. A tropical wave, ejecting off the west coast of Africa, and traveling into the central Atlantic then helps to develop a surface low-pressure system which is then gradually strengthening into a tropical storm.. A tropical cyclone could quickly become a hurricane or even a violent, major hurricane of greater than Category 3 strength when all the required conditions are near perfect.. Usually, near the peak Atlantic hurricane season, a strong influence on these factors brings intense tropical systems toward the Caribbean and the United States.. As we can see from the chart below, tropical storm Danielle has taken the advantage of this significantly warmer oceanic water, and rather quickly intensified into the first hurricane of the Atlantic season.. It often happens, that the explosive development of tropical storms occurs when tropical cyclones encounter such warm and moist fuel at the sea surface.. When the tropical waves begin ejecting off the west coast of Africa, warmer than normal waters hint at the enhanced potential for significant tropical cyclone development.. According to the weather forecasts for the upcoming weeks, the Atlantic waters will remain very warm through the peak of the Atlantic hurricane season 2022.. The blue colors on the chart (cold) mean more favorable conditions for tropical cyclone development and the red colors (warm) are showing where there is a less favorable state for tropical cyclogenesis present.. This can clearly tell us that conditions on both sides of central America are less supportive of tropical development this week, but those are somehow better towards the central and eastern Atlantic where tropical storm Earl and hurricane Danielle are ongoing right now.
Cyclones is large system of winds & are accompanied by violent storms and bad weather. Here , you will get Tropical And Temperate Cyclones UPSC Notes
Tropical cyclones :->They are develop in the region between the Tropics of Capricorn and Cancer.. Extra Tropical cyclones (also called Temperate cyclones or middle latitude cyclones or Frontal cyclones or Wave Cyclones):->They occur in temperate zones and high latitude regions, though they are known to originate in the Polar Regions.. Tropical cyclones are strong low pressure centres that originate over oceans in tropical areas and move over to the coastal areas bringing about large scale destruction due to violent winds, very heavy rainfall (torrential rainfall) and storm surge. Large sea surface with temperature higher than 27° C. Presence of the Coriolis force to create a cyclonic vortex (hence they do not form at Equator because Coriolis force is zero) Small variations in the vertical wind speed.. A roughly circular area of comparatively light winds and fair weather found at the centre of a severe tropical cyclone is known as Eye of the cyclone.. The formation and initial development of a cyclonic storm depends upon the transfer of water vapour and heat from the warm ocean to the overlying air, primarily by evaporation from the sea surface.. A tropical cyclone begins to weaken in terms of its central low pressure, internal warmth and extremely high speeds, as soon as its source of warm moist air begins to ebb or is abruptly cut off.. Extratropical cyclones are referred to as mid-latitude depressions, temperate cyclones, frontal depressions and wave cyclones.. Extratropical cyclones present a contrast to the more violent cyclones or hurricanes of the tropics, which form in regions of relatively uniform temperatures.. An anticyclone is the opposite of a cyclone i.e. i.e., it has an outward-spiralling air circulation around a high pressure centre.. Anticyclones form from air masses cooler than their surrounding, leads to contraction of air making it denser, thereby increasing surface air pressure.
Table of Contents
Geographically tropical atmosphere lies between the Tropic of Cancer and the Tropic of Capricorn.. Easterly waves Tropical depressions Tropical storms Hurricane and Typhoons. the name ‘hurricane’ is given to the tropical cyclone in N. Atlantic and eastern N. Pacific Ocean.. The tropical cyclones are found at certain seasons in well defined areas it the tropics.. On Indian Ocean the movement of the tropical cyclones is different because these storms are influenced by monsoon circulation, and they move in northerly direction along with the monsoon currents.. There are no hurricanes in south Atlantic regions due to the fact that the tropical convergence zone remains to the north of the equator so that no weak tropical disturbance develops over this ocean.. Tropical North Atlantic – West Indies, Gulf of Mexico and Caribbean sea, – Western part of the tropical North Pacific- Philippines, the China Sea and areas around Japan Eastern part of the tropical North pacific- western coastal areas of Mexico and central America The Bay of Bengal and Arabian sea The South Indian oceans – Fiji Islands and east coast of Australia. A storms surge is an abnormal rise of sea level near the cost caused by severe tropical cyclones, as a result sea water enters in to the low lying areas of coastal regions drowning human beings and live stocks, eroding beaches and destroying vegetation.