Describe how each of the following factors affects the climate of Africa (a) Latitude (b) Ocean currents (c) Distance from the sea

Answer Details

How each factor affects the climate of Africa.

(a) Latitude

Latitude determines the angle at which the sun's rays strike the earth and hence the amount of heat received. Areas near the equator (low latitudes) receive the sun's rays almost vertically and are therefore hot throughout the year with heavy convectional rainfall. As one moves towards the tropics and higher latitudes, the rays become more slanting, temperatures fall and rainfall becomes seasonal and lower, giving savanna, desert and, in the far north and south, warm temperate (Mediterranean) climates. Latitude thus explains the broadly symmetrical arrangement of climatic belts north and south of the equator.

(b) Ocean currents

Ocean currents affect the temperature and rainfall of coastal areas. Warm currents, such as the warm Mozambique/Agulhas current off south-east Africa and the warm Guinea current, raise coastal temperatures and, by warming the onshore winds, encourage rainfall. Cold currents, such as the Benguela current off the south-west coast and the Canaries current off the north-west coast, lower coastal temperatures and chill the onshore air so that it holds little moisture; this produces aridity and coastal deserts (e.g. the Namib and part of the Sahara) and coastal fogs.

(c) Distance from the sea (continentality)

The sea moderates temperature, so places near the coast have a small annual range of temperature (cool summers, mild winters) and receive more rainfall from moisture-laden sea breezes. Places far inland in the interior of Africa are cut off from the moderating and moistening influence of the sea; they therefore have a large range of temperature (very hot days and cool nights, hot summers and cool winters) and low, unreliable rainfall, giving continental and desert conditions.