Tropical cyclones are also referred to as hurricanes. They are formed when heat is released as moist air rises, during evaporation. The resultant; condensation of water vapor, fuels the formation of cyclonic windstorms and polar lows. This phenomenon leads to the formation of a warm-core storm system.
Hurricanes are commonly observed along the equator doldrums and tropical regions of the planet. The counterclockwise rotation observed in the Northern Hemisphere and clockwise rotation of winds recorded in the Southern Hemisphere, differ in strength according to location and surge.
Hurricane Formation and Characteristics
The movement of warm air, within the hurricane, from the tropics to the temperate latitudes, makes them a major air circulation mechanism. The other advantages of hurricanes include their role in relieving drought and maintaining the troposphere's equilibrium.
Tropical hurricanes have a core of 'sinking' air, also referred to as the 'eye of the hurricane'. Interestingly, the weather in this core region is calm and cloud free. The spherical formation may range in size from 2.5 kms to 370 kms in diameter! The 'stadium effect' refers to the outward curving of the eye-wall, to resemble a stadium.
The hurricane also has a CDO or Central Dense Overcast. This region is the concentrated thunderstorm bearing region near the center or eye of the hurricane. The size of a hurricane is usually determined on the basis of the measurement from the 'center of circulation' to the outermost 'isobar'.
Interesting Facts about Hurricanes
Storms over the North Atlantic or the Caribbean are termed as hurricanes. Storms occurring in the western Pacific Ocean, are known as typhoons. Whereas storms or hurricanes forming over the Indian Ocean are termed as cyclones.
In the 19th century an Australian weatherman named Clement Wragge, came up with the idea of naming hurricanes. Since then all hurricane names were women's names. In 1979, men's names were added to the list.
A detailed study of the tropical water temperature variations, rapid cooling with altitude, high humidity, low wind shear, and the presence of a previously existent disturbance in weather, is very important to understand the phenomenon.
Hurricane activity is most commonly observed in late summer. This is mainly due to the striking difference between sea temperatures and seasonal basin patterns, within each identified temperature zone. While May is observed as the least active hurricane month, September is considered the most active, worldwide.
The six Regional Specialized Meteorological Centers worldwide are responsible for tracking hurricanes. These laboratories also issue warnings and advisories about hurricane formations in the designated areas. They function alongside six Tropical Cyclone/Hurricane Warning Centers, that ensure awareness in smaller regions.