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Hurricanes and Tropical Cyclones

Hurricane Isabel
Photo by Expedition 7 crew onboard the ISS
September 17, 2003
A tropical cyclone is a storm system characterized by a low-pressure center and numerous thunderstorms that produce strong winds and heavy rain. Tropical cyclones may also be known as hurricanes (NW Atlantic Ocian), typhoons (NW Pacific Ocean) or simply as cyclones. A hurricane is a tropical cyclone with winds of 74 miles (119 kilometers) per hour or greater that occurs especially in the western Atlantic, that is usually accompanied by rain, thunder, and lightning, and that sometimes moves into temperate latitudes. Over the past two centuries, tropical cyclones have been responsible for the deaths of about 1.9 million people worldwide. Large areas of standing water caused by flooding lead to infection, as well as contributing to mosquito-borne illnesses. Hurricanes also have beneficial effects can also be important factors in the precipitation regimes of the places they affect and bring much-needed rain to otherwise-dry regions. Hurricanes in the eastern north Pacific sometimes supply moisture to the Southwestern United States and parts of western Mexico. Additionally, Japan receives over half of its rainfall from typhoons.

Hadley Cells
Image Source: 
NASA's Remote Sensing Tutorial
"This illustration from NASA describes the patterns of wind movement on the global scale. The sun heats the air over the equator more than at the poles. This differential heating causes warmer, less dense air near the equator to rise, and cells of convection develop. These are called Hadley cells. At the surface, the cells generate winds. On the image, the large arrows show the directions of surface wind flow in the different zones. Red and blue indicate the relative temperatures of the winds. You can see that global winds point towards the equator in the tropics and towards the poles between 30 and 60 degrees latitude. Use your mental visualization skills to imagine how these surface winds would look on a flat map of the world.

Based on these two images, is there a connection between global wind patterns and the movement patterns of hurricanes? In your own words, describe how global wind patterns illustrated in the first image influence the overall patterns you see in the second image." (source)