GENERAL OVERVIEW

Tropical Cyclone is the generic name for all hurricanes, typhoons, cyclones etc. They all have a unique character of Revolving about a centre and so are also called Revolving Storms. To understand the term ?Revolving?, if you keep a bucket of water and try to stir it such that both the upper and the lower layers of the water are rotating in your direction of stir, leaving a hollow in the middle of the bucket from the top to the bottom (equivalent to the ?eye? of the storm in a real tropical cyclone), then that is a perfect description of how a tropical cyclone behaves, the difference being that the bucket of water is the microscale while the real thing has a diameter of at least 500km (312.5miles) and a height in the range of 10-15km. You may wonder why a storm should begin to rotate. Well, they acquire this character from the rotation of the earth itself. As they (the storms) move farther away from the equator, a factor known as the Coriolis Parameter (from Coriolis force - after the founder G.G de Coriolis, a French Physicist) becomes significant in the Atmospheric Motion Equation.

The term ?Tropical? is a reflection of their ?birth place? as they all originate from tropical waters (oceans). The speed of associated winds is very critical for them to be termed tropical cyclones ? they must reach or exceed 118km/h (74mph).

The different names they are called is merely a reflection of the region where they form, just as a man from China may be named Lee, and a South African male Zuma or an American of same sex Fleming. All these are males with the genetic make-up of males and would act as any other male irrespective of what part of the globe he was born. So it is with Tropical Cyclones. Different names are used in various parts of the world to denote them. The name Typhoon is used in the Western North Pacific Ocean (west of the international dateline), Hurricane in the North Atlantic, Papagallos in the Eastern North Pacific Ocean, Trovado near Madagascar, simply Cyclones in the Indian Ocean and Bay of Bengal, Willy-Willy in Australia, and Baguio in the Philippines.

FACTS ABOUT THE FORMATION OF TROPICAL CYCLONES

Tropical Cyclones do not form in regions within 5 degrees N or S of the Equator. The most favourable latitude belts are 5-15 degrees N or S. However in the Southern Hemisphere (SH) they do not form beyond 22 degrees S while in the Northern Hemisphere (NH) they still form in latitudes as high as 35 degrees N.

There are 7 Tropical Cyclone Basins around the world where these types of storms occur on a regular basis: (i) The Atlantic Basin (including the North Atlantic, the Gulf of Mexico, and the Caribbean Sea). (ii) Northeast Pacific Basin (from the coast of Mexico to 140 degrees west longitude). (iii) North Central and Northwest Pacific Basin (from 140 degrees west, through the international dateline to the Philippine and south China seas). (iv) North Indian Basin (the Bay of Bengal and the Arabian Sea). (v) Southwest Indian Ocean Basin (from about 100 degrees east to the south eastern coast of Africa. (vi) Southeast Indian Ocean/Australian basin (from about 100 degrees east to the northwest coast of Australia. (vii) Australia/Southwest Pacific Basin (from the eastern coasts of Australia to areas beyond the international dateline).

Research has shown that two-thirds of all Tropical Cyclones form in the eastern hemisphere ? the tropical northeast Pacific (off the coast of Mexico), the south China and the Philippine seas and the Bay of Bengal. The other one-third form in the tropical waters of the West Indies and the Gulf of Mexico, the stretch of SH tropical ocean from around the International dateline (Between 170 degrees E and 180 ) through Australia to the coasts of Africa.

On rare occasions, tropical cyclones (or tropical/subtropical systems appearing to be similar to tropical cyclones) can develop in the Mediterranean Sea. These have been noted in September of 1947, September of 1969, January of 1982, September of 1983, and January 13-17 of 1995. For readers familiar with the Bible this may be similar to the storm (given the level of destruction and that it even had a name) encountered by Apostle Paul and others on their voyage to Italy on the Mediterranean way back in time.

Although the majority of tropical cyclones form in the summer, genesis is possible in all seasons in the western north Pacific (south China and the Philippine seas ? this region alone is reputed to have nearly one-third of all the globe's tropical cyclones).

The southeast Pacific (off the coasts of Chile and Peru) and south Atlantic (the Atlantic waters between Africa and Latin America) are not affected by cyclones.

Cyclones formation is especially favoured near the location of the ITCZ (Inter tropical Convergence Zone ? the zone of the convergence of NH and SH air masses particularly over the ocean). 80-85% of these cyclones originate in or just on the poleward side of the ITCZ.

The Sea Surface Temperature (SST) is usually above 26 degrees C (79 degrees F) to a depth of 60m.

Nothing can withstand the awesome force of nature. Most times the Atmosphere's reaction against man is a backlash of man's action against it. When the atmosphere reacts violently, know how to defend your life by knowing why it acts the way it does. There's always something new, topical, sizzling hot, refreshing, exhaustive and very authoritative about the weather and the atmosphere at cheap-bargain-mall.com/globalweather.html that you will need when the weather threatens to snuff life out of you as it has done to many.

In Part 2, we will examine their most likely season of occurrence, destructive power and how you can protect your life when it strikes. And in Part 3, we will look at Centres empowered to monitor and issue cyclone warnings as well as how cyclones get their names. See the names of ?unborn? cyclones up to 2013.