Geography Arid

Arid

Where is it Usually Located? Nearly 33% of the Earth's land is covered in Arid climate.  If land has an Arid climate it is usually a desert.  Most deserts are found along the 30 degree latitude line (north and south of the equator).  This is due to the pattern of cold water currents, which force dry air over the land.  Other Arid climates exist in the center of continents or in the rain shadow of large mountain ranges.  A rain shadow is land on a side of a mountain that is very dry because the mountain forces warm air higher into the sky, which cools it and it falls as rain, but only on one side of the mountain.    What Seasons Does it Have? Most Arid areas do not have regular seasons. For instance the Sahara Desert is always hot and dry.  However, some places do have changes in temperature depending on the latitude and the surrounding climates.  So, since there are temperature differences, we can say there are 2 seasons, summer and winter.   What are the Temperatures like? Temperatures can reach as high as 55 degrees or as low as negative -1 degrees.  The temperatures will depend on the latitude of the desert.  The farther from the equator the colder they will be.  On the map above you can see areas of cold desert (light red) and hot desert (dark red), and distance from the equator is clearly the cause.   How Much Precipitation Does it Receive? Precipitation (or the lack of) is the main factor that defines Arid climate.  To have an Arid climate, an area must receive less than 25 centimetres of rain per year.  However, many areas of arid climate receive far less than that.  Some deserts around the world don't receive 10 inches of rain in 10 years!  The Atacama Desert in Chile is known as the driest place on Earth. 1 millimetre of rain per year.  Cold currents carry dry air, so these lands are blasted with dry air most of the year, which causes the low precipitation.   What Kinds of Vegetation (Plants) Does it Have? There are a few Arid climate areas that are so dry that no plants can survive, such as Atacama Desert.  However, many Arid climate areas do receive some rain (up to 10 inches a year), so you will find vegetation in most Arid areas.  To survive in this climate, plants must either require very little water or be able to store water.  The plants often have long roots and thorns.  Some examples are scrub bushes, grasses, and cactus.   Saguaro Cactus                    Prickly Pear                                     Aloe Vera What Kind of Animals Does it Usually Have? Over thousands of years certain animals have adapted to the lack of water and extreme temperature to survive in an Arid climate.  Camels store water in their bloodstream and can drink 160 litres of water in 10 minutes, allowing them to go days without water.  Foxes and jackals can also be found in deserts around the world.  Snakes such as the Sidewinder and scorpions can also survive the Arid climate.   Sidewinder                                        Desert Fox                            Scorpion                     Camel