More cyclones in Arabian Sea in recent years
- In recent years, the frequency of ""extremely strong cyclonic storms"" over the Arabian Sea has grown.
- However, because the majority of these cyclones made landfall in Oman and Yemen, the threat to India's western coast was not much heightened.
- An review of historical cyclone data across the North Indian Ocean (Bay of Bengal and Arabian Sea) from 1891 to 2020 shows that the frequency of ""extremely severe cyclonic storms"" over the Arabian Sea has increased in recent years.
Factors responsible for the change
- The Arabian Sea's surface temperatures have risen substantially during the last century as a result of global warming.
- The current temperature is 1.2–1.4 ° Celsius greater than it was four decades ago. Active convection, torrential rainfall, and strong cyclones are all supported by the higher temperatures.
- The Arabian Sea is now able to give enough energy for cyclones to intensify as a result of rising temperatures.
- The Arabian Sea also provides cyclones with favourable wind shear. For example, Cyclone Ockhi's depression was driven from the Bay of Bengal to the Arabian Sea by a stronger easterly wind.
- Types: Tropical cyclones and ExtraTropical cyclones (also called Temperate cyclones or middle latitude cyclones or Frontal cyclones or Wave Cyclones).
- 'Tropical Cyclone': Describes meteorological systems with winds greater than 'Gale Force' (minimum of 63 km per hour).
- Tropical cyclones originate In the area between the Tropics of Capricorn and Cancer.
- They're large-scale weather systems that form over tropical or subtropical oceans and merge into surface wind circulation.
- Extra tropical Cyclones: Though they are known to originate in the Polar Locations, they may be found in temperate zones and high latitude regions.
- The Bay of Bengal, the Arabian Sea, and the Indian Ocean are all hotspots for tropical cyclones.
- The Indian coastal states of Tamil Nadu, Andhra Pradesh, West Bengal, Odisha, and Gujarat were affected by tropical storms with significant wind speeds and heavy rainfall (These five states are more vulnerable to cyclone disasters than others in India).
- Because of the strong wind speeds and copious rain that accompany them, the majority of these cyclones are quite destructive.
Elements associated with Cyclones
- Strong Winds/Squalls: They cause damage to installations, residences, communications systems, trees, and other structures, resulting in death and property loss.
- Torrential rains and inland flooding: Rain is a major issue for those who have lost their shelter as a result of the typhoon. Heavy rainfall is frequently dispersed across a considerable region, resulting in large-scale soil erosion and embankment deterioration.
- Storm Surge: A powerful tropical cyclone causes an abnormal rise in sea level along the shore. Storm surge inundation low-lying coastal areas, killing people and cattle, eroding beaches and embankments, destroying vegetation, and reducing soil fertility.
Trend of increasing cyclonic activities in the Arabian Sea
- Tropical cyclones in the Arabian Sea were once confined to Gujrat. Even Kerala and Karnataka have been increasingly vulnerable to cyclones in recent years. 'Ockhi' is a recent example.
- Tauktae is the fourth cyclone to form in the Arabian Sea in the last two years. In 2018, Cyclone Mekanu attacked Oman, in 2019, Cyclone Vayu hit Gujarat, and in 2020, Cyclone Nisarga hit Maharashtra.
- Since 2018, all of these storms have been classified as 'Severe Cyclones' or above.
- Tauktae became VSCS in just two days, whereas Cyclone Mekanu and Cyclone Nisarga required four and five days, respectively.
- The increased frequency of cyclones over the Arabian Sea has not resulted in a corresponding increase in coastal vulnerability along the west coast, because most of the cyclones that form over the Arabian Sea make landfall over the coasts of Oman, Yemen, and other countries, and thus the threat to Gujarat and Maharashtra remains the same.
- On average, 60 percent to 80 percent of cyclones that formed over the North Indian Ocean (NIO), which includes the Bay of Bengal and the Arabian Sea, made ashore, bringing death and property damage.
- West Bengal, Odisha, Andhra Pradesh, Tamil Nadu, and Puducherry's low-lying coastal districts were especially vulnerable to the effects of these systems.
Concerns associated with changing trends
- The impact of the cyclonic storm on the struggle against Covid-19 is a source of worry.
- Monsoon Delay: Cyclone Tauktae is projected to obstruct the regular course of the Indian Monsoon by drawing all of the moisture from the monsoon winds and funnelling it towards itself.
- Flooding has also grown thrice across India as a result of widespread heavy rainfall occurrences.
- Because they do not adequately integrate ocean dynamics, even the best state-of-the-art cyclone models are unable to predict this quick intensification.
Initiatives launched by Government towards Cyclones
- National Cyclone Risk Mitigation Project (NCRMP) to upgrade cyclone forecasting, tracking, and warning systems in India
- Integrated Coastal Zone Management Project (ICZMP) to improve national capacity for the implementation of comprehensive coastal management in India