Paper
Hurricanes are powerful atmospheric vortices that are intermediate in size. Hurricanes are unique and powerful weather systems. The word ?hurricane? comes from a Caribbean word meaning ?big wind?. Views of hurricanes can be seen from a satellite positioned thousands of miles above the earth.
Hurricanes originate as tropical disturbances over warm oceans with trade winds. The tropical turbances intensify into tropical depressions, and eventually into a tropical storm. They only originate in the tropical trade winds because the ocean temperatures are quite warm there. Powered from the heat that the sea gives off, they are steered by the east trade winds and the temperate west ones, as well as by their own ferocious energy. Around their core, winds grow with a tremendous amount of velocity creating violent seas. As they move toward the shore, they move the ocean inward, while spawning tornadoes and producing torrential rains and floods.
For a hurricane to form, the ocean temperature must be warmer than twenty-six degrees Celsius, or eighty degrees Fahrenheit. Also, the air near the oceans surface must be filled with moisture. The seawater that is warmed by the heat from the sun evaporates to form vast storm clouds. As the warm air rises, the cooler air replaces it thus creating a wind. The rotation of the earth bends the wind inward causing it to rotate and spiral upward with a great amount of force. Around the Equator, the spin is the fastest. There, it can be faster than six hundred miles per hour.
You cannot see a hurricane all at once, unless you?re looking at it from above or are looking at a picture taken by a satellite, because it is too large. The whirling mass, shaped like a donut, can be two hundred to six hundred miles wide and forty thousand to fifty thousand feet high. Towns can be ripped from the land and small countries entirely devastated by the raging winds.
The eye wall is a ring of fierce thunderstorms surrounding the center of a hurricane. As the air rushes toward the center, it becomes dense with water vapor. The vapor rapidly rises and condenses, forming towering thunderstorms. The rain fall is heaviest here.
Within the eye wall, the winds are the strongest. They move around so fast that it is difficult to hear, see, and even breathe. While over the ocean, these winds can create waves that are taller than three story buildings. But while they are over land, they can tear apart homes, uproot trees, and cause an enormous amount of destruction.
The eye of a hurricane is the low-pressure region in the center. The size of the eye depends on the strength of the surrounding winds. Stronger winds wrap themselves more tightly around the eye so that it becomes smaller. The average eye of a hurricane is about twenty miles wide with an oval shape although they can be round, too.
Even though the eye of a hurricane is calm and sunny, it can be dangerous. People are often fooled into thinking that the hurricane has passed. They come out of their homes or shelters and the fierce winds, wall of clouds, and downpour begins again. The other side of the storm arrives and it is as violent as it was before.
When a tropical disturbance appears in the Atlantic Ocean, the Caribbean Sea, or the Gulf of Mexico, the scientists at the National Hurricane Center are put on alert. Using weather satellites, they can find the exact location of the disturbance. Also, weather balloons equipped with measuring instruments are launched twice daily around the world to help detect spot changes in temperature and water vapor in the atmosphere.
When a disturbance grows and forms a tropical storm, meteorologists give it a name taken from a list of twenty-one common male and female names. They go down the list alphabetically, alternating with male and female names. A different list is used each year for six years at which point they are repeated. Once a storm causes severe damage, its name is removed from the list and is no longer in use. Hurricane Andrew in 1992 is an example of a hurricane name that is no longer in use, and so is Hugo in 1989 and Gilbert in 1988. Once the storm is named, hurricane hunters do the dangerous job of tracking it.
Nothing can divert a hurricane yet, however, meteorologists issue warnings so people in the path of a storm can evacuate the area or prepare themselves as much as possible. Strong sea defenses and hurricane shelters provide good protection. It can cost millions of dollars to evacuate an area, board homes and offices, close down businesses, and take other steps to prevent hurricane damage. If a storm doesn?t arrive as predicted, people of that area are less likely to pay attention to the next hurricane warning. Scientists try to be as certain as they can about where and when a hurricane will strike before they issue watches and warnings.
In the event that a hurricane does occur where you live, get an early start on evacuating the area. If you wait just a short amount of time, the roads and highways will be jammed with frantic people trying to reach safety. You should always listen and follow any given directions immediately. If you don?t have to leave, put all the outside things that might blow away in a safe place such as lawn furniture, bicycles, and toys. Water mains can also break, so filling containers with drinking water is a good idea. Put enough to last several days.
Once the storm arrives, stay inside and away from walls and windows that could collapse or be blown away. If it is during the night, have a flashlight near-by so that you can find your way around in case of a power failure. Don?t use the telephone either unless it?s absolutely necessary. Many people may be trying to make emergency calls and the phone lines may be knocked down in some areas.
Once, the ?All Clear? is given on the radio or television by local officials, be careful if you have to go outside. Stay away from downed power poles, live wires, dangling tree branches, and broken water or sewer mains. Always be careful when a hurricane warning is called and don?t joke around about it. don?t forget to be safe and take all necessary precautions.
! |
Как писать рефераты Практические рекомендации по написанию студенческих рефератов. |
! | План реферата Краткий список разделов, отражающий структура и порядок работы над будующим рефератом. |
! | Введение реферата Вводная часть работы, в которой отражается цель и обозначается список задач. |
! | Заключение реферата В заключении подводятся итоги, описывается была ли достигнута поставленная цель, каковы результаты. |
! | Оформление рефератов Методические рекомендации по грамотному оформлению работы по ГОСТ. |
→ | Виды рефератов Какими бывают рефераты по своему назначению и структуре. |