Ciclons

Ciclons, or cyclones, are large-scale low-pressure systems in which winds rotate around a central region of relative calm. The term is used in many languages to describe tropical cyclones as well as mid-latitude cyclones. Depending on their origin and location, cyclones may be called hurricanes, typhoons, or simply cyclones.

Most tropical cyclones form over warm ocean waters and derive energy from the condensation of moist air. They require sea surface temperatures above 26.5 C, sufficient depth of warm water, high humidity in the mid-troposphere, and low vertical wind shear. They typically develop westward and poleward away from the equator, aided by the Coriolis force.

Structure includes an eye at the center, surrounded by an eyewall of the strongest winds, with rainbands spiraling outward. The most destructive effects come from strong winds, heavy rainfall, and storm surge along coastlines, which can cause flooding and infrastructural damage.

Lifecycle and classification: Tropical cyclones pass through stages from tropical disturbance to tropical depression, tropical storm, and then to a hurricane, typhoon, or cyclone when sustained winds exceed 119 km/h (74 mph). Extratropical cyclones form in mid-latitudes through different mechanisms and may evolve from tropical systems.

Forecasting and monitoring rely on satellites, radar, weather stations, and reconnaissance aircraft. Computer models predict track and intensity and are used to issue warnings, evacuations, and preparedness measures to reduce risk to populations and property.

Global patterns vary by basin. Major cyclone basins include the North Atlantic, Northeastern Pacific, Northwestern Pacific, Indian Ocean, and Southern Hemisphere. Seasonal activity and climate influences such as sea temperature patterns and wind shear affect frequency and intensity.