Pressure Gradients Essay Example for Free

Pressure Gradients EssayThe atmosphere is composed of a mixture of gases. Air has weight which is say towards the centre of the reality. The take out (weight) of billet per unit area acting on object on the terra firma is called the atmospheric pressure (Diane, 11). The atmospheric pressure is measured by an instrument called a barometer. On a map, regions of equal pressure are linked by lines called isobars. These lines are drawn in such a way that they never cross each other. The drawing of these lines is based on the average sea train pressure reports. It is true that majority of the weather stations are situated some heath preceding(prenominal) sea level.Therefore the pressure measured at a crabbed place has to be born-again into sea level pressure before the isobars are drawn. This is due to the fact that pressure decreases with increase in height and the pressures on maps should be as a result of weather conditions and not due to changes in height(Integrated Publis hing). According to Diane, Pressure differences occur due to differences in the heat absorbed by the land or water. When bearing is heated, it expands reducing its density and rises. A partial vacuum is therefore created. Cold denser air f confuseds to prepare up the space left by the rising air.Basically wind scats from a region of graduate(prenominal) pressure to a region of down(p) pressure. Therefore, as the pressure changes from place to place, the speed of wind withal changes. Diane defines pressure gradient as the rate of change of pressure at a particular sequence in a particular place. The major power that pushes air from a region of high pressures to the region of low pressure is called the pressure gradient force. The force is greater when the pressure gradient is high. Eady notes that the speed of wind depends on the pressure gradient, being higher(prenominal) with greater pressure gradient. It could be expected that the wind will flow perpendicular to the isobar s.However the pressure gradient force is somewhat circular as it depends not single on pressure gradient but also on Coriolis exit, centrifugal force and frictional force (Eady, 142). Coriolis force is brought about as a result of the rotation of the earth. All particles at the climb up of the earth rotate once every day. Since the radious is greater at the equator than towards the poles, an object rotates faster at the equator than at higher latitudes. If air moves northwards due to pressure gradient force, it gives it horizontal motion in accordance to atomic number 7s first law of motion (Ferrel, 98).The air therefore moves in a North east wind direction. In actual sense, wind flows in a circular path (integrated Publishing). For a body to maintain a circular path, centripetal force must be provided. In accordance to Newtons third law of motion an equal and opposites force called centrifugal force acts on the body (Eady, 139). This force tends to push winds out of their path s and it increases with speed of wind. As wind flows over objects over the earths surface it experiences fractional drag. This drag results to wind flowing at an angle to the isobars near the earths surface.At higher altitudes air flows parallel to the isobars (Joseph). Diane Fisher contends that in some cases, air cools at a particular place in the troposphere. The cooling results into contraction of air which in turn leads to increase in bay window per unit volume of air. This leads to increased pressure directed downwards. This air then attempts to flow outwards towards regions of low pressure. But due to Coriolis force, the air is made to rotate clockwise in the northern hemisphere and anticlockwise in the southern hemisphere. This is referred to as an anticyclone.On the other hand, Diane tells us that a region of rising air of low pressure is called a cyclone. This occurs at the boundary of cold and warm air. It is caused by warm air rising and cools air descending which crea tes of reduced pressure. An inward pressure gradient is created and in addition to Coriolis Effect causes air to circulate in anticlockwise direction in the Northern Hemisphere and Clockwise in the Southern Hemisphere. The cyclone usually moves upwards and it contributes to the circulation of air in the atmosphere. Works Cited Diane Fisher.Become a weather angiotensin-converting enzyme. In The Technology Teacher, Vol. 61, 200211 15. Eady, E. T. The general circulation of the atmosphere and oceans. In The Earth and Its Atmosphere, ed. D. R. Bates. New York, Basic Books, (1957)130-151. Ferrel, W. The work of the Earths rotation upon the relative motion of bodies near its surface. Astron. J. , Vol V. No. 109, (1858)97-100. Integrated Publishing . http//www. tpub. com/content/aerographer/14312/css/14312_16. htm Joseph E forefront Riper. Mans Physical World. New York McGraw-Hill Book Company, Inc. 1962.