A hurricane is storm emanating from the tropical temperatures that typically in summer. They are synonymously known as tropical cyclones or typhoons, depending on where they occur (Americas or Asia). These ferocious storms can agitate the seas into violent scenario, making coastlines so violent to the extent that, they can reduce whole cities to watery ruin. These geographical phenomenon occur every year, the world experiences hurricane season. During this period, hundreds of storm systems spiral out from the tropical regions surrounding the equator and many of these storms intensify into hurricane levels. In the Northern Hemisphere, the season runs from June 1 to Nov. 30, where as the Southern Hemisphere by and large experiences hurricane activity from January to March. For nearly three quarters of the year, it’s safe and the world is not worrying about any prospect of a hurricane. A hurricane may build its power as it moves across the ocean, sucking up warm, moist tropical air from the surface and dispensing cooler air up. This is like, the storm “breathing” in and out. The hurricane escalates until this “breathing” is disrupted, like when the storm makes landfall. The gases that make up Earth’s atmosphere are subject to the planet’s gravity. As a matter of fact, the atmosphere weighs in at a combined 4.99 quadrillion metric tons. The gas molecules at the bottom, or those closest to the Earth’s surface where we all live, are compressed by the weight of the air above them. The air closest to us is also the warmest, as the atmosphere is mostly heated by the land and the sea, and not by the sun. Imagine that you are walking bare footed on a paved walkway, your feet feel like burning. It is not the heat from sun that is “burning” your feet but that from the pavement. Likewise, when air heats up, its molecules move farther apart, making it less dense. This movement is called a pressure gradient force. It is these basic forces at work when a low-pressure centre that form in the atmosphere a centre that may turn into what people in the North Atlantic, North Pacific and Caribbean regions call a hurricane. Sincerely speaking, warm, moist and air from the ocean’s surface begins to rise rapidly. As it rises, its water vapour condenses to form storm clouds and droplets of rain. The condensation releases latent heat (latent heat of condensation). This latent heat warms the cool air, causing it to rise. This rising air is replaced by more warm, humid air from the ocean below. And the cycle continues, drawing warmer, moist air into the developing storm and moving heat from the surface to the atmosphere. This exchange of heat creates a pattern of wind that circulates around a centre. Most probably, that is why some people call it a cyclone! Converging winds at the surface are colliding and pushing warm, moist air upward. This rising air strengthens the air that’s already raising from the surface, so the circulation and wind speeds of the storm increase. In the meantime, strong winds blowing the same speed at higher altitudes 9,000 meters; these help to remove the rising hot air from the storm’s centre, maintaining a continual movement of warm air from the surface and keeping the storm organized. However, If the high-altitude winds don’t blow at the same speed at all levels the storm becomes disorganized and it gets weakened. eddie@afrowebs.com
