Explain how atmospheric circulation gives rise to the formation of low and high pressure areas in your chosen climatic region

Explain how atmospheric circulation gives rise to the formation of low and high pressure areas in your chosen climatic region. Illustrate and explain the seasonal changes in the distribution of these pressure systems. The circulation of the atmosphere in Tropical regions is described by Hadley's cell. This is affected by two main processes, and pressure gradient force is the first of these. This says that air will move from the area of higher pressure to an area of lower pressure. The greater the difference in pressure, the stronger the airflow will be. The second main process is Coriollis' force. The rotation of the Earth deflects the air moving across the Earth's surface. The rotation deflects air to the right in the Northern Hemisphere and the left in the Southern Hemisphere. These two forces play a major part in the Global Circulation that is the key to the World's climates. Hadley's Cell explains the Tropical circulation; this is a direct cell, as it is a result of direct heating from the sun. It begins at the Equator, where the most intense solar radiation is found, making it the hottest place on Earth. The warm air rises from the Equator causing low pressure. This area of low pressure is often called the Doldrums, and is an area of heavy convectional rainfall. The rising air now spreads out pole wards and cools. The cooling air sinks over the tropics, creating high

  • Word count: 947
  • Level: AS and A Level
  • Subject: Geography
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Rain by Somerset Maugham - Comment on the significance of the recurrent image of rain in this short story.

English Rain: Somerset Maugham. Task: Comment on the significance of the recurrent image of rain in this short story. Rain, by Somerset Maugham seems to have a rather irrelevant title when first looked at. The first part of the story that introduces us to the story have no relevance to rain, or any other weather feature for that matter. However, as the story progresses, rain, and metaphors about the weather play a very important part in the story, and it sets the mood of the story. We do not get an image of the weather until page 8 (page numbers from collected short stories vol.1). However when the rain is introduced it happens very quickly and it moves the story on. 'But Mrs Davidson had given two or three of her birdlike glances at heavy grey clouds that came floating over the mouth of the harbour. A few drops began to fall. "We'd better take shelter," she said. They made their way with all the crowd to a great shed of corrugated iron, and the rain began to fall in torrents.' This quote shows how immediate the rain came. It seems to the reader that as soon as they have shelter, the rain falls intensely. It is also interesting here, because it seems that they have only been on the island for a few minutes, but yet then, the rain starts. The reader gets an impression of nature versus the English-men. We get the impression that nature is fighting the white men and

  • Word count: 1679
  • Level: AS and A Level
  • Subject: Geography
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Energy tranfers within the atmosphere

Energy transfers in the atmosphere The source of energy for our planet is the sun. The sun's energy moves through space, and then through the earth's atmosphere and then finally reaches the earth's surface. This energy is then absorbed by the earth's surface and is then re-radiated as heat energy. There are three ways that heat energy is transferred through the atmosphere, radiation, conduction and convection. Conduction happens near the ground as heat energy is passed on through the movement of heat particles. All heat energy travels from a warmer region to a cold region, therefore the rate of conduction depends on factors such as temperature, surface area and the given levels of conductivity for various substances. The conduction of heat energy through the atmosphere is intensified by the amount of heat energy, which is radiated by the sun to be absorbed by the earth's surface. The transaction of heat energy from the sun to the earth is known as radiation. This is how the earth receives the heat energy emitted from the sun. This radiant heat energy is also absorbed by the earth's surface, this is what provides us with an average surface temperature of 14/15 degrees C. The heat energy absorbed by the earth's surface fluctuates in certain regions of the atmosphere due to various factors i.e. clouds absorbing heat, the sun's orbital path and the

  • Word count: 1216
  • Level: AS and A Level
  • Subject: Geography
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Climatic Hazards (Atmospheric Circulation)

Climatic Hazards (Atmospheric Circulation) Our planet is made up of many different climate zones that are located in different parts of the world and climate is the main reason why we have different areas such as rainforests and desserts. The main major climate zones are 'tropical' where rainforests are located at tropical latitudes on the equator with some exceptions, e.g. Indonesia. Australia and Northern Brazil are good examples of large rainforests. The sun is high up in the sky and these areas gain a lot of sunlight throughout the year averaging temperatures of approximately 34°c. Polar is a major climate zone and is of course mainly around the Poles b between 60-90°c North and South. These climates are very dry and freezing cold with fairly mountainous terrains e.g. Antarctica. Arid is a very important world climate and consist mostly of our very dry and warm areas e.g. our desserts. They are located around the tropic of cancer and tropic of Capricorn in countries such as North Africa where we have the Sahara dessert. These are very dry because prevailing winds come over the land and land masses are very large. Finally we 'temperate' climates such as in the UK which are located 40-60°c North and are fairly dry but can also be very wet and are also very cold with a lot of vegetation growth. I have stated that major climate zones are clearly caused by our climate but

  • Word count: 1115
  • Level: AS and A Level
  • Subject: Geography
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Temperature Inversions.

Temperature Inversions Normally, the air near the ground is warmer than the air at higher altitude. An inversion is the reverse situation--colder air at ground level than higher up. Cold air is heavier than warm air. Thus once an inversion forms, the air is very stable. Mixing that would normally occur by the rising of warm air is inhibited. Consequently pollutants such as carbon monoxide, sulphur compounds and ice fog remain trapped near the ground when there is an inversion. Types of Inversions The stability and mixing of air near the surface is controlled to a great degree by the presence of temperature inversions in the lower atmosphere. These inversions typically are very extensive, blanketing entire cities or regions. In each case, warm air is produced over a layer of cooler air in contact with the surface. There are basically four types of temperature inversions, each are explained below. Marine Inversions If you live near a coastline, you have probably experienced a marine inversion layer. Near cool oceans, such as in the western U.S. and Western Europe, a marine inversion can turn a hot summer day at the beach into a cool, foggy, overcast shiver. The ocean is typically quite cool compared with the land, particularly at middle latitudes where the heating by sunlight is not strong. Air sitting over cold water also tends to be cool. Moreover, a great deal of

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  • Level: AS and A Level
  • Subject: Geography
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The Sahel and the ITCZ

The Sahel and the ITCZ Air masses moving over Africa have different characteristics depending on their areas of origin. Air originating over the tropical oceans, known as maritime tropical air, is warm, moist, and unstable. When this moisture-laden air is forced to rise and become cooler, condensation and precipitation often occur. Conversely, the hot, dry air that originates over the African continent (continental tropical air) is incapable of producing rain, even if it is forced to rise. Over most of Africa, air moves toward the equator. Northern Hemisphere winds from the northeast and Southern Hemisphere winds from the southeast converge at the intertropical convergence zone (ITCZ), a low-pressure zone centred on the equator. Air rises at the ITCZ, spreads out, and descends in the north and south, in subtropical high-pressure zones centred on the Tropic of Cancer and Tropic of Capricorn. After descending, the air flows outward, either pole ward into temperate regions or back toward the equator. The ITCZ constantly shifts its position, moving north of the equator during the Northern Hemisphere's summer, and south of the equator during the Northern Hemisphere's winter (see below diagram). This shift brings about seasonal changes, notably in the tropical summer rainfall zone. During the summer season (July to September in the Northern Hemisphere and December to February in

  • Word count: 889
  • Level: AS and A Level
  • Subject: Geography
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The aim of this project was to investigate what differences exist in temperatures in the local area, and to consider the effects of certain geographical aspects on these.

Introduction The aim of this project was to investigate what differences exist in temperatures in the local area, and to consider the effects of certain geographical aspects on these. This is in relation to the unit of work on Climate, Environment and People contained in the GCSE Geography syllabus, and this project uses principle ideas from this unit of study. There are many factors that affect the temperature of a region, be they on a grand scale, such as across a country or continent, or in a very small area, where a few environmental differences, such as the shelter of a building or tree, can cause a difference in temperature of one or two degrees Celsius. On a national scale, the latitude of the location will obviously have an effect, a fact clearly illustrated by the e difference in temperature between a temperate region, such as London, and a tropical rainforest town, such as Manaus in Brazil. This effect can also make a difference on a smaller scale; there is a one or two degree temperature variation between the cities of Portsmouth and London in the UK, which are only 120 km apart. Altitude is another major factor, as it is generally cooler at higher altitudes than it is at sea level, hence the appearance of snow at the top of mountains at even the warmest of latitudes. This is due to the density of the air, which decreases as the altitude increases. It is

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  • Level: AS and A Level
  • Subject: Geography
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For my primary data I went to Southend-on-Sea and asked people questionnaires about their trip to the coast. My questionnaire included questions about where they came from

Methodology My coursework is set in Southend-on-Sea is in the county of Essex, in South-East England, on the north bank of the Thames estuary. For my coursework I went to the coast of Essex and did some research on my computer about the area. I used primary data and secondary data. For my primary data I went to Southend-on-Sea and asked people questionnaires about their trip to the coast. My questionnaire included questions about where they came from, why they came and what they liked about the area. I stood at two ends of the town. First I stood at the furthest away from the beach end on the High Street and then I did another on the beach front. I did this so I got a range of recording. I got 50 from one end and 50 from the other end. I did my questionnaires at the two marked points on my map below. The questions on my questionnaires were chosen for certain reasons. My first question was 'What was your main purpose here today?' I chose this question as my main experiment was to find out why people were coming to Southend-on-sea. My second question was 'Why did you choose Southend-on-sea?' I chose this question mainly to back up the first question but also to see what attracted people in a general sense not just what they were doing now. My third question was 'Did you come with:' I chose this question mainly for my general curiosity and to see whether people they came with

  • Word count: 955
  • Level: AS and A Level
  • Subject: Geography
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Sahelian Drought Investigation

Sahelian Drought Investigation The word Sahel is Arabic for edge or shore of the desert, and it refers to a strip of arid land which runs across Africa, from the 'Horn of Africa' in the East to Mauritania in the West. . Water is precious because rainfall is both infrequent and sparse. The latitude of the region is about 10-150 North and is 3.800 km East to West and 700 km North to South. The countries within the Sahel are Mauritania, Mali, Niger, Chad, Sudan, Ethiopia and Somalia. The normal climate in summer in the Sahel region has the sun and ITCZ overhead so therefore onshore tropical maritime winds occur & there many areas of low pressure are produced. This climate creates large cumulus-nimbus and other types of clouds that cause convectional rain. One of many reasons why there is drought in the Sahel region is because the winter conditions which are completely different to the summers dominate and continue throughout the year. The usual wind directions in the mid-summer were reserved and dry whilst stable continental air dominated instead of moist, unstable maritime air. Therefore, fewer clouds are formed bringing less rain. Year after year of drier than average conditions meant the impact on people was severe. Global warming is another cause of drought as it means there are less clouds produced from condensation due to the global temperatures increasing. The region

  • Word count: 614
  • Level: AS and A Level
  • Subject: Geography
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Discuss the relative importance of physical and human factors in accounting for changes to vegetation over time within ecosystems in the British Isles

Discuss the relative importance of physical and human factors in accounting for changes to vegetation over time within ecosystems in the British Isles The British Isles is an example of a Lithosere succession, in that it began as bare rock from glacial retreat. The plant succession started with the pioneer species which were algae and bacteria. Both began to broke down rock surface through weathering. Then lichens and mosses began growing in the area which helps with water retention and provides a base for soil. The next stage of primary succession is herbs/grasses/flowering plants/ferns. These add nutrients and organic matter to the ground which provided soil. Next, shrubs invaded and colonised the area. Shrubs dominate and shade out the sere below them. Small trees such as birch and willow were the following sere which invaded and colonised the area. They produced humus from leaf fall which provided nutrients for the soil through nutrient recycling and encouraged new growth of the sere. The last sere is the larger trees which are oak and ash which dominate the area and shade out smaller trees. This sere is the climax community in that it is stable and no further succession happens after. The climax community is the deciduous woodland biome we know today. The main characteristics include the location in which they are found, which is in temperate maritime climate such as

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  • Level: AS and A Level
  • Subject: Geography
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