Cyclones, also known as hurricanes or typhoons, are primarily caused by high ocean temperatures, broad-scale wind systems and clustered thunderstorms, which liberate the heat energy from the ocean surface and transfer it to the cyclone. Ocean temperatures must be higher than 80 degrees Fahrenheit to a depth of at least 150 feet.
This heat from the ocean combines with the Earth's rotation to create the cyclone's spin and propulsion. As the cyclone moves across cooler waters, land or into unfavorable wind systems, it gradually begins to dissipate as it loses energy.
There are a number of additional atmospheric conditions that must be present in order for a cyclone to form, including moisture layers in the mid-troposphere, approximately 3 miles above the Earth's surface, and low vertical wind shear between the Earth's surface and the upper troposphere. Cyclones also need to be at least 310 miles from the equator, where the deflective Coriolis force of the planet's rotation begins to take effect.
Depending on the caliber of these conditions, a cyclone's center, or eye, can grow to be more than 62 miles in diameter, although 25 miles is more typical.
A cyclone's severity is measured on a 5-point scale, ranging from Category 1, which have gales of between 56-78 kilometers per hour causing possible damage to trees and lightweight structures, to Category 5, which have very destructive winds of up to 173 miles per hour, causing widespread destruction and loss of life.Learn More
According to Collins English Dictionary, "cyclone" describes a violent tropical storm or hurricane. In Australia and New Zealand, "cyclone" is an adjective used to describe fencing that is made of interlaced wire and metal, although this definition is considerably less common.Full Answer >
A cyclone is formed when a system of winds moving in circular motion closes in toward an area of the sea with low atmospheric pressure. The formation of cyclones occurs in four stages including formative, immature cyclone, mature cyclone and decay stage. Cyclones usually form in the eastern Pacific Ocean, southern Atlantic Ocean, Gulf of Mexico and the Caribbean Sea. A cyclone is usually accompanied by thunderstorms.Full Answer >
The 1970 Bhola cyclone was the deadliest tropical cyclone of all time, claiming between 300,000 and 500,000 lives in the Ganges River Delta and causing approximately $490 million worth of damage in U.S. dollars. Its strength equaled that of a category 3 hurricane.Full Answer >
A mid-latitude cyclone, also known as an extratropical cyclone, is a huge low-pressure system of synoptic scale that is found in the middle latitudes. It has a cyclonic flow, but it is not a tropical storm or a hurricane. It causes windy and wet weather, and occurs most often in the United States during the winter season.Full Answer >