Super Typhoon Hinnamnor

Syllabus: General Studies Paper 1

The strongest global storm of 2022 is barreling toward the East China Sea, threatening Japan’s southern islands but posing only a potential risk to Taiwan or China’s east coast.

• Super typhoon Hinnamnor, currently several hundred kilometers to the east of Okinawa, is expected to skirt the Japanese islands this weekend. 
• The storm is packing sustained winds of about 150 miles (241 kilometres) per hour and has gusts around 184 mph, according to the US Joint Typhoon Warning Center.
• Hinnamnor would be the strongest storm of 2022 based on the maximum sustained wind speed recorded at this point.

Cyclones

• Cyclones are a type of low-pressure environment with rapid inward air circulation.
• In the Northern Hemisphere, air flows counter clockwise, while in the Southern Hemisphere, it circulates clockwise.

Tropical Cyclones

• The term ‘Tropical Cyclone’ is used by the World Meteorological Organization to describe weather systems with winds greater than ‘Gale Force’ (minimum of 63 km per hour).
• Tropical cyclones are formed in the region between the Tropics of Capricorn and Cancer.
• They’re large-scale weather systems that form over tropical or subtropical oceans and coalesce into surface wind circulation.
• Tropical cyclones are one of the world’s most destructive natural disasters.

Conditions for formation of Cyclones

• A consistent source of heat as tropical cyclones are thermally induced low-pressure systems.
• Large sea surface with a temperature higher than 27° C which is possible only during the late summers i.e. September, October, and November
• Presence of the Coriolis force.
• 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.

Origin of Tropical Cyclones

• Tropical cyclones arise over tropical oceans in late summers and have a thermal origin (August to mid-November).
• Because of the Coriolis effect, the powerful local convectional currents take on a whirling motion at these regions.
• These cyclones form and move until they reach a weak place in the trade wind belt.

Structure of Tropical Cyclone

• The structure of a Tropical Cyclone is typically a massive cumulonimbus cloud with rapidly rising air spiraling upwards at the margins of the eye. 
• An eye is a region of calm with subsiding air. Around the eye is the Eyewall, where strong spiraling winds ascends and the height can reach up to the tropopause.

Tropical cyclones are formed by the following parts:

• Eye: The eye is the center of cyclones which is characterized by a calm area, sinking, and light wind. The eye is the calmest part of the Cyclone structure.Conservation of angular momentum and centrifugal force are the reasons behind its formation.
• Eyewall: A band around the eye of the greatest wind speed, where clouds reach the highest and precipitation is the heaviest. The heaviest wind damage occurs where a hurricane’s eyewall passes over land.
• Rain Bands: Curved bands of clouds and thunderstorms that trail away from the eyewall in a spiral fashion. These bands are capable of producing heavy bursts of rain and wind. Sometimes gaps are found between spiral rain bands, where no impact (wind or rain) of cyclones are found.

Local Names

• North Atlantic (including Caribbean and Gulf of Mexico): Hurricanes
• Eastern and Central North Pacific: Hurricanes
• Western Northern Pacific: Typhoons
• Arabian Sea/Northern Indian Ocean: Tropical Cyclones
• South Indian Ocean: Tropical Cyclones/Willy-Willy for southwest Australia
• Coral Sea/South Pacific: Tropical Cyclone.