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.Continue Reading
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 about Storms
According to NASA, hurricanes form when warm, calm ocean waters create a rotating convection current in the air above the surface. As the warm, humid air rises, it creates a cloud layer in the cooler regions of the atmosphere, and surface winds blow into the low pressure center. Over time, this air circulation may cause the clouds to rotate, allowing them to draw more moisture and energy from below.Full Answer >
A typhoon is a tropical cyclone that occurs in the Northwest Pacific Ocean, explains the National Ocean Service. Typhoons, cyclones and hurricanes are all the same type of weather disturbance, but different names are used depending on the storm's location. Hurricanes occur in the Atlantic and Northeast Pacific Oceans, while cyclones occur in the South Pacific and Indian Oceans.Full Answer >
Like other tropical cyclones, typhoons form when warm, calm ocean waters transfer warmth and moisture to the air above the surface. The air rises into cooler layers of the atmosphere, allowing the water to condense and the air to fall back down. This sets up a convective current that draws moisture and energy into the clouds and causes them to begin to spin.Full Answer >
Hurricanes occur because during the summer months, warm air over the ocean rises to leave an area of low pressure, into which cool air immediately flows. This air too warms up and rises, and new pockets of cool air take its place. As the cycle repeats itself, the warm air eventually cools far above the surface to create clouds, and a hurricane can form.Full Answer >