Why Temperature Varies Over the World

Why Temperature Varies Over the World

There are two different sorts of factors that alter the answer to this

question and these are long-term and short-term factors.

Long-term factors

Land and sea areas mostly influence atmospheric temperature. This is

evident in the colder months when it is evident that the waters in the

same area are always colder than the land the same areas. In the

summer months this is totally reversed.

Land and sea differ in their ability to absorb, transfer and radiate

heat energy. The sea is more transparent than the land, and is capable

of absorbing heat down to a depth of 10 metres. It can then transfer

this heat to greater depths through movements of waves and currents.

The sea also has a greater specific heat capacity than that of land.

Specific heat capacity is the amount of energy required to raise the

temperature of 1kg of a substance by 1degree Celsius, expressed in

kilojoules per kg per degrees Celsius. The specific heat capacity of

water is 4.2kj/kg/degree c. That of soil is 2.1kj/kg/degree c and that

of sand is 0.84kj/kg/degree c. This all means that water requires

twice as much energy as soil and five times more than sand to raise an

equivalent mass to the same temperature. During summer therefore the

sae heats up more slowly than the land. In winter, the reverse is the

case and land surfaces loose heat energy more rapidly than water. The

oceans act as efficient 'thermal reservoirs' this is why coastal

environments have a lower annual range of temperature than locations

at the centres of continents.

Ocean currents are a major factor in the variations of temperatures

across the world, due to the process of horizontal transfer of heat

energy. Warm currents carry water pole wards and raise the temperature

of the maritime environments where they flow. Cold currents carry

water towards the equator and so lower the temperatures of coastal

areas. The mean difference of one place and the mean same monthly

totals of places with the same latitude; this difference is known as