Effect on rainfall


A place’s altitude does not affect its rainfall. Some places at low altitudes get plenty of rain, while others get hardly any rain. And the same is true for places at high altitudes. The very dry Namib and Gobi deserts are examples of this. The Namib Desert along the coast of Namibia is at sea level, while the Gobi desert of Central Asia has an average altitude of 1 000 m but is much higher in some places. Both places receive hardly any rain at all.


The Namib desert, Namibia Ocean currents


Ocean currents are streams of water that move through the sea. Some ocean currents are warm, while others are cold.


New word


evaporating: a liquid changing into a gas


Currents affect temperature because the water temperature affects the temperature of the wind blowing over it. A cold current will lower the wind’s temperature and a warm current will raise it. When the wind blows over the land, it will, in turn, affect the temperature of the land. The coast next to a warm current usually gets more rain than the coast next to a cold current. This is because the wind blowing over a warm current is warmed by it, and can hold a lot of moisture evaporating from the sea. If it blows on shore, it takes this moisture with it, increasing the chance of rain. However, wind blowing over a cold current will not collect moisture from the cold water surface, and will therefore be dry when it reaches land, making rain unlikely.


Gobi desert, Central Asia


The effects of currents on temperature. 52 Module 3 Climate regions


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