News:Many places in Maharashtra, Goa and Karnataka are receiving rains for the last few days, mainly because of cyclonic Karr in the Arabian Sea.
About Cyclone Kyarr:
- Cyclone Kyarr is a tropical cyclone that has intensified west of India in the Northern Indian Ocean’s Arabian Sea.
- It is the second most intense super cyclonic storm on record in the Arabian Sea in the last 12 years.
- The only stronger storm on record in the Arabian Sea was 2007’s Tropical Cyclone Gonu.
About Tropical Cyclones:
- Tropical cyclones are storms that originate and intensify over warm tropical oceans.
- They are intense low pressure areas with very strong winds circulating around it in anti-clockwise direction in the Northern Hemisphere and clockwise in the Southern Hemisphere.
- The central calm region of the storm is called the “Eye“. The Eye is surrounded by Eye wall which is the region with heaviest precipitation and strongest winds
Tropical Cyclones are known by different names in different regions:
- Cyclones in Indian Ocean
- Hurricanes in Atlantic
- Typhoons in Western Pacific in South China Sea
- Willy-Willies in Western Australia
Necessary Conditions for development of a tropical cyclone:
- Continuous supply of abundant warm and moist air
- Sea temperature in lower latitudes should be around 27°C
- A distance from the Equator is necessary, so that it allows the Coriolis Effect to deflect winds blowing toward the low pressure centre.Tropical cyclones develop in inter-tropical convergence zone
- Pre-existence of weak tropical disturbances
- Presence of anticyclonic circulation at the height of 9 to 15km above the surface
- Low vertical wind shear between the surface and the upper troposphere. Vertical wind shear is the magnitude of wind change with height.
About India Meteorological Department (IMD)
- India Meteorological Department (IMD) was established in 1875.It is an agency of the Ministry of Earth Sciences of the Government of India.
- It is the principal agency responsible for meteorological observations, weather forecasting and seismology.
- IMD ranks cyclones on a 5-point scale- a) Cyclonic storm, b) Severe cyclonic storm, c) Very severe cyclonic storm, d) Extremely Severe cyclonic storm and e) Super cyclonic storm.
- Cyclonic Storms have storm force wind speeds of between 62–88 km/h. Severe Cyclonic Storms have storm force wind speeds of between 89–117 km/h.
- Very Severe Cyclonic Storms have hurricane-force winds of 118–166 km/h.Super Cyclonic Storms have hurricane-force winds of above 222 km/h.