What is a cyclone?Almost everyone is interested in the weather - it looks forecasts, reports.He often hears about cyclones and anticyclones.Most people are aware that these atmospheric phenomena are directly related to the weather outside.In this article we will try to find out what they are.
What
Cyclone Cyclone - is a zone of low pressure system covered by circular winds.Simply put, it is a grand flat atmospheric vortex.Moreover, the air therein spirals around hub gradually approaching it.The reason for this phenomenon is considered to lower the pressure in the central portion.So warm, moist air masses sweep up, rotating around the center of the cyclone (the eye).This causes accumulation of clouds high density.In this area raging strong winds, which can reach a speed of 270 km / h.In the Northern Hemisphere rotate air is counterclockwise with a certain twist to the center.In anticyclones contrary, air is twisted clockwise.A tropical cyclone in the Southern Hemisphere works almost as well.However, the directions are reversed.Cyclones may reach different sizes.Their diameter can be very large - up to several thousand kilometers.For example, a large cyclone is able to fully cover the European continent.Generally these atmospheric phenomena generated in certain geographic locations.For example, the southern cyclone comes into Europe from the Balkans;the Mediterranean, Black and Caspian Seas.
mechanism of formation of cyclones - the first phase
What is a cyclone and how it is formed?At the front, ie in the areas of contact between warm and cold air masses, arise and develop cyclones.It formed a natural phenomenon when the mass of cold polar air meets warm, moist mass.This warm air masses burst into an array of cold forming in them something like a language.This is the beginning of the birth of the cyclone.Sliding relative to each other, these streams with different temperature and density of air creating waves on the front surface, and hence on the most front line.It turns formation resembling an arc facing concavity in the direction of warm air masses.Her segment located in front of the eastern part of the cyclone is a warm front.The western part, which is located in the rear of atmospheric phenomena is a cold front.In between them are often found in the cyclone zone of good weather that usually lasts only a few hours.Such deflection of the front line is accompanied by a decrease in pressure at the top of the wave.
evolution of the cyclone: the second phase
atmospheric cyclones continues to evolve further.Founded wave, moving, usually to the east, north-east or south-east, gradually deformed.Language warm air penetrates further north, forming a well-defined warm sector of the cyclone.In the front of the warm air mass slides over a cold and dense.When lifting the condensation of steam and the formation of cumulus rain clouds, which leads to precipitation (rain or snow) that last long.The width of the zone of frontal precipitation occurs in the summer, about 300, and in winter - 400 km.At a distance of several hundred kilometers to the warm front at the surface updraft it reaches a height of 10 km or more, at which the condensation to form ice crystals.Of these, white cirrus clouds are formed.Therefore, it is possible for them to predict the approach of a warm front of the cyclone.
third phase of the formation of atmospheric phenomena
Further characterization of the cyclone.The moist warm air of the warm sector, passing over a cold surface of the Earth, forming a low stratus clouds, fog, drizzle.After passage of a warm front comes cloudy weather with warm southern winds.The signs of this often is the appearance of haze and light fog.Then approaching cold front.The cold air passing along it, swam under warm and displaces it up.This leads to the formation of cumulonimbus clouds.They are the cause of showers, thunderstorms, accompanied by strong winds.Width of precipitation cold front is about 70 km.Over time comes to replace the back of the cyclone.She brings strong winds, cumulus clouds and cool weather.Over time, the cold air pushes warm to the east.After that set clear weather.
How are cyclones fourth phase
As the penetration of warm air in the language of the mass of cool, it is surrounded by more cold air masses, and the displaced upwards.It creates in the center of the cyclone zone of lower pressure where the surrounding air masses rush.In the Northern Hemisphere under the influence of Earth's rotation, they turn counterclockwise.As mentioned above, southern cyclones have opposite direction of rotation of air masses.Due to the fact that the Earth revolves on its axis, the winds are not directed toward the center of the atmospheric conditions, and are tangent to a circle around it.In the development of the cyclone, they are amplified.
fifth phase of the evolution of the cyclone
cool air in the atmospheric phenomenon is moving at a faster rate than warm.Therefore the cold front cyclone gradually merges with warmer, forming the so-called front occlusion.At the Earth's surface is no longer hot zone.There are only cold air masses.
Warm air rises, which gradually cooled and released from the moisture reserves, which fall to the ground in the form of rain or snow.The difference in temperature between the cold and warm air is gradually leveled.This cyclone begins to fade.However, the complete homogeneity in these air masses do not.Following the data of the cyclone near the front on the crest of a new wave occurs second.These atmospheric phenomena are always lots, each next few south of the previous one.The height of the cyclone vortex often reach the stratosphere, that is raised to a height of 9-12 km.Particularly large can be found at altitudes of 20-25 km.
speed cyclone
Cyclones almost always in motion.The speed of movement can be very different.However, it decreases with the aging of the atmospheric phenomena.In most cases, they move at a speed of about 30-40 km / h, for 24 hours passed away 1000-1500 km or more.Sometimes they move at a speed of 70-80 km per hour and more passes per day of 1800-2000 km.At this rate the cyclone, which is now raging in the area of England, 24 hours may already be in the area of Leningrad or Belarus, triggering a sharp change in weather.As we approach the center of the atmospheric phenomena pressure drops.There are different names of cyclones and hurricanes.One of the most famous is the "Katrina", which caused extensive damage in the United States.
atmospheric fronts
What cyclones, we have already dealt with.Next will be a speech about their structural components - the atmospheric fronts.What makes a huge mass of moist air in the cyclone rises high up?To answer this question, we need first to understand what constitutes the so-called atmospheric fronts.We have already said that the warm tropical air moves from the equator to the poles and on its way meets cold air masses of temperate latitudes.Since the properties of warm and cool air are very different, it is natural that their files can not immediately mix.In place of meeting of air masses of different temperatures there is a clear strip - the transition zone between the fronts of air with different physical properties, which in meteorology called the front surface.Zone separating air masses of temperate and tropical latitudes, called the polar front.A front surface between the temperate and boreal latitudes called the Arctic.Since the density of the warm air mass is smaller than that of the cold, then the front is an inclined plane which always leans towards the array under cold extremely small angle to the surface.Cool air is denser, at a meeting with the last heat rises up.Imagining front between air masses, you must always keep in mind that this is - the imaginary surface is tilted above the ground.Outside the front line, which is formed at the intersection of the surface of the earth, marked on weather maps.
Typhoon
wonder whether there is in the nature of something beautiful such thing as a typhoon?Clear sky over the calm of a well established mad swirl penetrated zigzags of lightning, wall height of two Mount Everest?However, big trouble threatens anyone who would be at the bottom of the well ...
Originating in equatorial latitudes, typhoons are directed to the west, and then (in the northern hemisphere) turns to the north-west, north or northeast.Although each of these repeats is not exactly the path of movement of another, most of them moves on a curve which has the shape of a parabola.Speed typhoons increases as one moves north.If near the equator and in the direction they are moving to the west at a rate of just 17-20 km / h, then after the turn to the northeast of their speed can reach 100 km / h.However, there are times when, unexpectedly deceiving all the predictions and calculations, typhoons something completely stop the mad rush forward.
Eye of Hurricane Eye
a bowl with convex walls of clouds, in which there is a relatively light wind or no wind.The sky is clear or partly covered by clouds.Pressure is 0.9 times the normal value.Eye typhoon may have a size from 5 to 200 kilometers in diameter, depending on the stage of its development.The young hurricane eye size is 35-55 km, and have developed it is reduced to 18 km s0.Under the eye of the typhoon damping increases again.The clearer it is delineated, the more powerful typhoon.In these hurricanes winds are stronger at the center.Closing all flows around the eye, the winds swirling at speeds up to 425 km / h, gradually slowing down as the distance from the center.
