highcliffe2

Around the world, many people are fascinated about the weather. This phenomenon can take lives and we run our daily lives according to it. Every country in the world has its own particular and unique climate. For instance, the continent of Africa is often dry and hot, the two poles are unbeilevably cold with no set population. Over the centuries and milleniums, the climate has changed in more ways than one. Ice Ages, heatwaves, periods in time where the earth warms or cools. Currently Global Warming has said to be the cause for the dramatic rise in temperatures over the last century. This year again Global Warming has been brought up due to the heatwave here in Britain and Europe, only last year floods were devastating the Low Countries. As yet there is no hard evidence to suggest that this is true. Weather fronts and weather patterns are constantly circling around the world then die away, new ones are then born. Air pressure is always bringing different types of weather. Low pressure is often associated with rain, high pressure with dry weather. To measure pressure, we use aneroid barometers in units of miilibars. This type of barometers contain hollow capsules with no air inside. As the pressure of the air alters, the capsules change shape and slowly move the pointer on the dial to show whether the air pressure is rising or falling. The highest pressure ever recorded was 1084 millibars in Siberia. The lowest was 870 millibars in a typhoon over the Pacific Ocean. The highest ever temperature ever recorded in the world is 58c or 136F, in Libya 1922. The lowest ever temperature recorded was -89.6c or -128.6F at Vostok Station, Antarctica in 1983. This was without wind chill. Here are the main weather types that affect each continent: Europe Although much of Europe lies in the northern latitudes, the relatively warm seas that border the continent give most of western Europe a moderate climate, with cool winters and mild summers. The prevailing westerly winds, warmed in part by passing over the North Atlantic Drift ocean current, bring precipitation throughout most of the year. In the Mediterranean climate area—Spain, Italy, and Greece—the summer months are usually hot and dry, with almost all rainfall occurring in winter. From approximately central Poland eastward, the moderating effects of the seas are reduced, and consequently cooler, drier conditions prevail. The northern parts of the continent also have this type of climate. Most of Europe receives 500 to 1,500 mm (20 to 60 in) of precipitation per year. Australasia Much of Australia is warm or hot around the year and even along the cooler southern coasts the winters are mild rather than cold. Serious bush fires can be caused by the prolonged heat waves and drought. Tropical cyclones occur or three times a year in the seas to the northeast and northwest of Australia. Africa Africa has virtually the same climatic zones in the Northern Hemisphere as in the Southern Hemisphere, and they are arranged symmetrically on either side of the equator. The zones are determined mainly by latitude, except in the east where highlands greatly modify the climate. Africa is the most tropical of the continents: Only its northern and southern extremes are directly influenced by mid-latitude westerly winds and are considered to have temperate climates. Africa has six types of climatic zones: tropical wet, tropical summer rainfall, semiarid, arid, highland, and Mediterranean. - Tropical Wet This particular climate is often known as equatorial climate and occurs to the climate in west and Central Africa. Rainfall is high, typically exceeding 1,500 mm (60 in) per year and 3,200 mm (130 in) in some places. Rainfall occurs in every month, and many areas experience especially rainy periods in the spring. Temperatures remain high throughout the year, averaging more than 27°C (81°F) annually, and rarely falling below 21°C (70°F). - Tropical summer rainfall This climate occurs north and south of the tropical wet zone, in much of western and southern Africa. With a dry season of three to eight months, annual rainfall is usually between 500 and 1,500m (20 and 60in). Temperature ranges in the tropical summer rainfall zone are slightly higher than in the tropical wet zone with daily high temperatures average more than 30c (86f) in the northern section of this zone. Due to the higher altitudes of the southern and eastern parts of this zone, the temperature tends to be cooler. - Semiarid and Arid The semiarid zone has a short rainy season of up to three months with a range of 250 to 500mm (10 to 20in) of rain per year. Rain is rare and makes plant growth difficult. Temperatures vary between 25 - 36c (77F - 97F). The arid regions of Africa receive small amounts of rainfall. They are classified as hot desert regions though many a time the regions don't live up to their name. During one day the temperatures can range dramatically. In the Sahara desert, daytime temperatures in the summer can exceed 50c (120F), though night-time temperatures during winter can drop below freezing. - Highland and Mediterranean Tropical highland climates are common in much of East Africa. Temperatures in the highlands of Ethiopia and Kenya average 16° to 21°C (60° to 70°F). In most parts of the world, higher elevations receive more rainfall than lower elevations, though the highlands of East Africa are the exception to the rule, receiving low levels of rainfall. The coasts of the region of Cape in South Africa and the North-western coast of Africa have a mediterranean climate. These regions have mild and rainy winters after a long summer where it is often warm and dry. The annual rainfall is between 250 and 1,000 mm (10 to 40in). North America's Climate This continent has a mumber of different climates, 5 in fact. The north of Canada, Alaska, and all of Greenland have subarctic and arctic climates. Winters are long and bitterly cold while summers are mild and short. Most of this region receives little precipitation and is covered in snow and ice for much of the year. A second climate is made up of most of the eastern side of the United States and southern Canada. It is a humid climate where all four seasons are evident. The southern part of this region has a higher average temperature. A third climatic region takes up the western side of the USA and most of northern Mexico. It is mostly mountainous and deserts are apparent, small amounts of rainfall. A fourth region is made up of a narrow strip along the Pacific Ocean, strectching from southern Alaska to southern California. It has mild but unusually wet winters and almost rainless in summer. The fifth and final climatic region is southern Mexico, where it is warm all-year round but a lot of precipitation, especially in summer. South America's Climate South America, the fourth largest of Earth's seven continents. South America is dominated by relativley warm weather and climates. Droughts are a serious problem in northeastern Brazil and along the northern coast of Venezuela and Colombia due to wet summers and dry winters. In the northern half of South America, only the Andes mountain range is cool. South of the tropic of Capricorn, South America have cool to warm summers and cool to cold winters. Antarctica Antarctica is the fifth largest continent, the coldest, windiest, highest, most remote and the most recently discovered continent. Only 2.4 percent of the continent is exposed rock, only 2 percent of the coast is exposed cliffs or beaches. The rest is made up of ice cliffs. It has a number of climates, all cold but differ largely in severity. The lowest year-round temperatures are found in East Antarctica's high plateau region around late August at Russia's Vostok Station. Air temperatures of the high inland regions fall below –80°C (-110°F) in winter and rise only to –30°C (–20°F) in summer. The warmest coastal regions reach the freezing point in summer but drop well below in winter. The interior of Antarctica is a windy polar desert with less than 50 mm (less than 2 in) of precipitation a year. Precipitation is greater in the milder coastal areas, averaging more than 200 mm (more than 8 in) annually, much of it in the form of snow dropped by cyclones. Asia Asia has every type of climate in the world. The main factors that influence Asia's climate pattern are its huge landmass, its location between the tropics and the arctic, and its huge range in elevations from sea level to high plateaus and mountains. The climate pattern that dominates most of Asia is the monsoon. This season includes the east, southeast and south of Asia. During winter, northern Asia receives little precipitation. This happens because cold, dry air moves southwards out of the Mongolian Plateau. During summer, this pattern is opposite where moist and warm air move north from the tropics. This is the time where rainfall is heaviest and more substantial, especially in southern Asia. This air mass continues its journey north but by this time the moisture has gone. This therefore shows that precipitation is heaviest in the south.

Humidity is a measure of the amount of (invisible) water vapour or the degree of dampness in the atmosphere. If the relative humidity and temperatures are high the air feels damp and murky. It is the condensation of this vapour which gives rise to clouds, rain, snow, dew, frost and fog The limit to how much water vapour the air can hold varies with temperature. Warm air can hold more vapour than cold air. When the air contains the maximum amount of vapour possible for a particular temperature, the air is said to be saturated. Usually the air is not saturated, containing only a fraction of the possible water vapour. The amount of vapour in the air can be expressed in a variety of ways. Absolute humidity indicates the actual amount of water vapour present in a sample of air, or the vapour concentration, the mass of water vapour in a given quantity of air. 1kg of air might hold up to 25 grams of water vapour in the tropics, but almost nothing in cold polar regions. Relative humidity is the ratio of the actual mass of vapour in the air to the mass of vapour in saturated air at the same temperature. For example, air at 10°C contains 9.4 g/m3 (grams per cubic metre) of water vapour when saturated. If air at this temperature contains only 4.7 g/m3 of water vapour, then the relative humidity is 50%. When unsaturated air is cooled, relative humidity increases. Eventually it reaches a temperature at which it is saturated. Relative humidity is 100%. Further cooling leads to condensation of the excess water vapour. The temperature at which condensation sets in is called the dew point. The dew point, and other measures of humidity can be calculated from readings taken by a hygrometer. Specific humidity is the ratio between the amount of water vapour in air and the total mass of the mixture of air and water vapour.