Tropical Cyclones
Posted by feww on May 6, 2008
What’s a Tropical cyclone?
A tropical cyclone is a storm system characterized by a low pressure center and numerous thunderstorms that produce strong winds and flooding rain. A tropical cyclone feeds on the heat released when moist air rises and the water vapor it contains condenses.
The term “tropical” refers to both the geographic origin of these systems, which form almost exclusively in tropical regions of the globe, and their formation in Maritime Tropical air masses. The term “cyclone” refers to such storms’ cyclonic nature, with counterclockwise rotation in the Northern Hemisphere and clockwise rotation in the Southern Hemisphere. Depending on their location and strength, tropical cyclones are referred to by other names, such as hurricane, typhoon, tropical storm, cyclonic storm, tropical depression and simply cyclone.
Map of the cumulative tracks of all tropical cyclones during the 1985–2005 time period.
Tropical cyclones can produce extremely powerful winds and torrential rain, as well as high waves and devastating storm surge. They develop over large bodies of warm water, and can cause significant damage to coastal regions flooding up to 40km from the coastline. Although inland regions are relatively safe from receiving strong winds, heavy rains can produce significant flooding inland. (Source)
Cyclones can relieve drought conditions
Known for devastating human populations, tropical cyclones can also relieve drought conditions. They also carry heat and energy away from the tropics and transport it towards temperate latitudes, which makes them an important part of the global atmospheric circulation mechanism. As a result, tropical cyclones help to maintain equilibrium in the Earth’s troposphere, and to maintain a relatively stable and warm temperature worldwide. (Source)
Structure of a tropical cyclone (Source: NOAA)
Cyclone Structure
Tropical cyclones are areas of low atmospheric pressure near the Earth’s surface. The pressures recorded at the centers of tropical cyclones are very low. Tropical cyclones are driven by the release of large amounts of latent heat of condensation, which occurs when moist air is carried upwards and its water vapor condenses.
Eye and inner core
A strong tropical cyclone will harbor an area of sinking air at the center of circulation. If this area is strong enough, it can develop into an eye. Weather in the eye is normally calm and free of clouds, although the sea may be extremely violent. The eye is normally circular in shape, and may range in size from 3 km to 370km in diameter. (Source)
Brief History:
The 1970 Bhola cyclone is the deadliest tropical cyclone on record, killing more than 300,000 people and potentially as many as 1 million after striking the densely populated Ganges Delta region of Bangladesh on November 13, 1970. Its powerful storm surge was responsible for the high death toll. The North Indian cyclone basin has historically been the deadliest basin, with several cyclones since 1900 killing more than 100,000 people, all in Bangladesh. Super Typhoon Nina caused major damage and deaths in China, mainly from the collapse of the Banqiao Dam. Hundreds of thousands of people died due to the resulting floods, making it one of the deadliest tropical cyclones recorded in history. The collapse of the dam due to heavy floods also caused a string of 60 or so smaller dams to collapse. (Source)
Global Warming and Hurricanes
Source: Geophysical Fluid Dynamics Laboratory
The strongest hurricanes in the present climate may be upstaged by even more intense hurricanes over the next century as the earth’s climate is warmed by increasing levels of greenhouse gases in the atmosphere. […]
According to a new simulation study by a group of scientists at NOAA’s Geophysical Fluid Dynamics Laboratory (GFDL), a 5-12% increase in wind speeds for the strongest hurricanes (typhoons) in the northwest tropical Pacific is projected if tropical sea surfaces warm by a little over 2°C (Figure 1). Recent preliminary findings indicate that these results may apply to the other tropical cyclone basins as well. […] (Source: OAR NOAA)
Recent Cyclones and Hurricanes:
- The most intense tropical cyclone ever recorded (watch this space for the record breakers!)
- List of notable tropical cyclones
- List of Atlantic hurricanes
- List of Pacific hurricanes
- List of tropical cyclones
feww said
JASBIR SINGH BHANGU – See below for additional links:
Severe Weather Information Center
• World Meteorological Organization Severe Weather Information Center http://severe.worldweather.org/
• Tropical Storms Worldwide
http://www.solar.ifa.hawaii.edu/Tropical/tropical.html
Specialized meteorological centers
• US National Hurricane Center
http://www.nhc.noaa.gov/
• Central Pacific Hurricane Center
http://www.prh.noaa.gov/hnl/cphc/
• Japan Meteorological Agency
http://www.jma.go.jp/en/typh/
• India Meteorological Department
http://www.imd.gov.in/
• Fiji Meteorological Service
http://www.met.gov.fj/index.php?id=152
• United States Tropical Cyclone Rainfall Climatology
http://www.hpc.ncep.noaa.gov/tropical/rain/tcrainfall.html
Relief Organization [allegedly]
• ReliefWeb international
http://reliefweb.int/rw/dbc.nsf/doc100?OpenForm
• American Red Cross
http://www.redcross.org/
JASBIR SINGH BHANGU said
MYANMAR
(1)DO THERE NOT EXISTS A MECHANISM, GLOBALLY TO MONITOR THE TEMPERATURES OVER SEA & EARTH MERELY TO HAVE AN INDICATION OF CYCLONE ETC?
(2)DO MYANMAR HAS NO SUCH A MECHANISM?IF IT HAS, THEN WHAT ARE THE REASONS THAT MYANMAR FAILED TO ANNOUNCE THE TIMELY WARNING AGAINST THE COMING OF CYCLON?
(3)AT PRESENTLY WHICH ARE THE COUNTRIES WHOSE TEAMS ARE WORKING FOR RESCUES?
(4)NAME ALL THOSE HUMAN RIGHT AGENCIES WHICH ARE ON WORK FOR RESCUES IN MYANMAR?
(5) IS THERE ANY ORGANISATION GLOBALLY WHO REGISTERS THE VOLUNTEERS FOR SENDING THEM TO RESCUES PURPOSES, WHENEVER/WHEREEVER NECESSITIES OCCUR?
(6)IS THERE ANY WEB THAT GIVES FULL DETAIL OF THE SITUATION WHEREEVER DEVASTATION TAKES PLACE?
(7) HAS THE VARIOUS GOVERNMENTS MADE THE PROCEDURES SIMPLE FOR THOSE WHO WANT TO RUSH THAT PLACE AS A RESCUE
(8)ARE THERE WELL PLANED COMMUNITY LANGARS(COMMUNITY KITCHEN-FREE MEALS)SWITCHED ON?
(9)HAVE THE COMMUNICATION STRONGLY REESTABILISHED?
(10)HAVE THE POWER SUPPLY SYSTEM BEEN RESTORED, WITH THE HELP OF ADJOINING COUNTRIES?
(11)HAVE THE HOSPITALS BEEN FUNCTIONING PROPERLY?
J.S BHANGU