Typhoon

Typhoon
MODIS image captured by NASA’s Aqua satellite · Public domain · source
Name	Typhoon
Caption	Satellite image of a mature tropical cyclone
Basin	Northwestern Pacific
Formed	Varies seasonally
Dissipated	Varies
Winds	Varies
Pressure	Varies

Typhoon Typhoons are intense tropical cyclones that develop in the northwestern Pacific Ocean and frequently affect countries such as Japan, Philippines, China, Taiwan, and South Korea. Originating from disturbances associated with the Intertropical Convergence Zone, Monsoon trough, and trans-equatorial tropical waves, typhoons interact with large-scale systems like the El Niño–Southern Oscillation, the Pacific Decadal Oscillation, and the Asian monsoon to influence regional weather, agriculture, and infrastructure. Agencies including the Japan Meteorological Agency, the Joint Typhoon Warning Center, and the Philippine Atmospheric, Geophysical and Astronomical Services Administration monitor and issue warnings using satellite networks such as Himawari, GOES, and METEOSAT.

Overview

Typhoons are part of the broader class of tropical cyclones that also includes hurricane and cyclone; they derive energy from warm ocean surfaces like the South China Sea, the Philippine Sea, and the Western Pacific Warm Pool. The regional impacts of typhoons have shaped historical events such as the Spanish colonial Philippines period, the Great Kanto earthquake relief efforts, and wartime operations like the Battle of Okinawa, while modern responses involve institutions like the United Nations Office for Disaster Risk Reduction, the International Red Cross and Red Crescent Movement, and national agencies in Vietnam and Thailand. Research on typhoons is conducted at centers including the WMO Tropical Cyclone Programme, the NOAA Atlantic Oceanographic and Meteorological Laboratory, and university groups at University of Hawaii and National Taiwan University.

Formation and Structure

Formation typically requires sea surface temperatures above 26.5 °C in regions such as the Philippine Sea and the South China Sea, low vertical wind shear influenced by patterns like ENSO, and pre-existing disturbances associated with the Intertropical Convergence Zone or remnant monsoon troughes. Mature typhoons exhibit organized features including an eyewall, radial rainbands, and an eye that may be observed by satellites like Himawari and aircraft reconnaissance from units such as the United States Air Force and the Japan Air Self-Defense Force in historical campaigns. Vertical structure includes warm-core thermodynamic profiles identified in dropsonde data collected by platforms from NOAA and research programs such as the Hurricane Field Program and collaborations with institutions like Scripps Institution of Oceanography.

Classification and Measurement

Regional classification uses intensity scales maintained by agencies: the Japan Meteorological Agency uses 10-minute sustained winds, the Joint Typhoon Warning Center issues 1-minute sustained wind estimates, and the China Meteorological Administration applies national criteria for warnings. Measurement techniques include satellite-based estimates using the Dvorak technique, scatterometer retrievals from satellites like QUIKSCAT, airborne reconnaissance and dropsondes deployed by NOAA and military units, and surface observations from buoys in networks maintained by JMA, NOAA, and institutions such as the Scripps Institution of Oceanography. Historical reanalysis projects at organizations like the International Best Track Archive for Climate Stewardship and the University of Hawaii adjust records alongside paleotempestology studies led by groups at UCSB and Brown University.

Regional Distribution and Naming

Typhoon genesis regions span the Western Pacific Basin with notable genesis hotspots near the Philippine Sea, South China Sea, and east of the Mariana Islands. National meteorological agencies including PAGASA, JMA, CMA, and the Korean Meteorological Administration maintain naming lists and retire names after damaging events, a practice coordinated by the World Meteorological Organization regional committee. Distinct naming conventions reflect cultural input from members such as Japan, North Korea, South Korea, Philippines, Thailand, and Cambodia, and historical notable storms have been given names that entered public consciousness like those chronicled in archives at the National Archives of Japan, the National Library of the Philippines, and the China Meteorological Administration.

Impacts and Hazards

Typhoons produce multiple hazards including extreme wind damaging urban centers exemplified by impacts in Tokyo, storm surge along coasts like Haiyan Bay and the Pearl River Delta, intense rainfall causing river flooding in basins such as the Mekong River and landslides in mountainous regions like the Cordillera Central (Philippines). Economic and social consequences affect sectors represented by institutions such as the Asian Development Bank, the World Bank, and national ministries in Malaysia and Indonesia, while public health responses involve the World Health Organization and national health ministries. Major historical events with catastrophic impacts include storms that influenced reconstruction after the 1923 Great Kanto earthquake and recent extreme events documented by agencies like the Japan Meteorological Agency and the Philippine Atmospheric, Geophysical and Astronomical Services Administration.

Preparedness and Mitigation

Preparedness measures draw on early warning systems operated by JMA, PAGASA, and regional tsunami and storm surge models developed at institutions like NOAA and the Asian Disaster Preparedness Center. Infrastructure resilience programs funded or advised by the Asian Development Bank, the World Bank, and national planning agencies in Japan and Philippines incorporate building codes, evacuation planning coordinated with local authorities, and community-based programs researched at universities such as University of the Philippines and National Cheng Kung University. International cooperation includes initiatives under the UN Office for the Coordination of Humanitarian Affairs and capacity-building projects led by the World Meteorological Organization and non-governmental organizations like Red Cross societies.

Category:Weather