Latitude
The strongest determinant of weather and climate, latitude is often used in climate classification, for example, tropical climate, temperate climate or polar climate types. The disparity in the distribution of the Sun's rays over the Earth or insolation is the main reason for the differences in weather and climate across the Earth. At the equator, solar rays approach the Earth at a 90 degree angle and are concentrated within a relatively small area. Due to the curvature and tilt of the Earth, temperate and polar regions are further away from the Sun and the solar rays have a wide area to heat up, thus they generally experience a heat deficit while the Equator experiences a heat surplus. This is also part of the reason for the differences in the length of days and nights in higher latitudes with polar regions receiving 24 hours sunlight or no hours of sunlight at different times of the year |
Click on the You Tube video below which gives a summary of the the factors affecting Earth's insolation.
Continentality
The land and sea heat up and cool down at different rates due to variations in density. During summer months in temperate and polar climates, the land heats up more rapidly than the sea, making inland areas much hotter than coastal areas. The reverse happens in the winter months when coastal areas are warmer than inland areas. An example is the UK which is said to have a maritime climate due to the influence of the sea. In contrast inland areas such as Russia are said to experience a continental climate.
The land and sea heat up and cool down at different rates due to variations in density. During summer months in temperate and polar climates, the land heats up more rapidly than the sea, making inland areas much hotter than coastal areas. The reverse happens in the winter months when coastal areas are warmer than inland areas. An example is the UK which is said to have a maritime climate due to the influence of the sea. In contrast inland areas such as Russia are said to experience a continental climate.
Notice the climograph on the left showing the sharp temperature variations over the year for continental interiors such as Omsk in Russia versus the much smaller temperature variations per annum in maritime areas such as Vancouver, BC in Canada (the climograph on the right).
Altitude
The atmosphere prevents heat from escaping into space. At the ground level, terrestrial energy (solar heat absorbed by the ground then re-radiated back into the atmosphere) heats up the lower layers of the atmosphere. Here the air molecules are closer together and have a higher pressure under the influence of gravity. As you go further from the Earth's surface, the air molecules begin to spread further apart, atmospheric pressure drops and the heat from the ground becomes less intense. In most places, temperature decreases by 0.6 degrees Celsius for every 100 metres above seal level. There are mountains such as the Andes in Venezuela that have snow on their summits even though they are located in the tropics.
The atmosphere prevents heat from escaping into space. At the ground level, terrestrial energy (solar heat absorbed by the ground then re-radiated back into the atmosphere) heats up the lower layers of the atmosphere. Here the air molecules are closer together and have a higher pressure under the influence of gravity. As you go further from the Earth's surface, the air molecules begin to spread further apart, atmospheric pressure drops and the heat from the ground becomes less intense. In most places, temperature decreases by 0.6 degrees Celsius for every 100 metres above seal level. There are mountains such as the Andes in Venezuela that have snow on their summits even though they are located in the tropics.
Relief
When a parcel of air meets a mountain, it is forced to rise. If it has been blowing over a body of water such as the sea, then this moist air will eventually condense to form clouds when its relative humidity reaches 100 percent. The precipitation that falls to the Earth is termed relief or orographic rain. As the now dry air moves down the other side of the mountain, it contracts and becomes warmer. The side of the mountain that experiences this dry air is called the rain shadow or leeward side, while the side that faces the moist up-blowing air is called the windward side.
When a parcel of air meets a mountain, it is forced to rise. If it has been blowing over a body of water such as the sea, then this moist air will eventually condense to form clouds when its relative humidity reaches 100 percent. The precipitation that falls to the Earth is termed relief or orographic rain. As the now dry air moves down the other side of the mountain, it contracts and becomes warmer. The side of the mountain that experiences this dry air is called the rain shadow or leeward side, while the side that faces the moist up-blowing air is called the windward side.
Prevailing winds, land and sea breezes
Most areas in the world have a dominant or prevailing wind which blows from one direction most of the time. In the Caribbean, they are the north-east trades which bring most of our rain and steers low pressure systems towards the islands. In Nigeria and Ghana, the Harmattan winds blowing from the Sahara Desert bring dry conditions for a part of the year but the south-east trades bring the moist air in the rainy season. In India, the Southwest monsoon winds bring torrential rain to most parts of the country in its rainy reason.
Land and sea breezes affect local weather and climate as well. When the land heats up during the day, the air in contact with the ground warms and rises creating an area of low pressure. Meanwhile the air over the sea which is a bit cooler and denser flows in the fill the vacuum left by the rising air. Those on the coast can often find relief from a gentle sea breeze on a hot day. At night the reverse occurs when inland areas are cooler that the coast. In this case a land breeze develops, which fishermen often use to give their boat a push to go out to sea.
Relief can also act as to break the speed of wind by creating friction. On windward slopes of the same altitude, wind speeds are often significantly greater than on the corresponding leeward side.
Most areas in the world have a dominant or prevailing wind which blows from one direction most of the time. In the Caribbean, they are the north-east trades which bring most of our rain and steers low pressure systems towards the islands. In Nigeria and Ghana, the Harmattan winds blowing from the Sahara Desert bring dry conditions for a part of the year but the south-east trades bring the moist air in the rainy season. In India, the Southwest monsoon winds bring torrential rain to most parts of the country in its rainy reason.
Land and sea breezes affect local weather and climate as well. When the land heats up during the day, the air in contact with the ground warms and rises creating an area of low pressure. Meanwhile the air over the sea which is a bit cooler and denser flows in the fill the vacuum left by the rising air. Those on the coast can often find relief from a gentle sea breeze on a hot day. At night the reverse occurs when inland areas are cooler that the coast. In this case a land breeze develops, which fishermen often use to give their boat a push to go out to sea.
Relief can also act as to break the speed of wind by creating friction. On windward slopes of the same altitude, wind speeds are often significantly greater than on the corresponding leeward side.
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