At the word “desert”, in fact, everyone has a picture in their head – heat, heat, a caravan of camels with travelers in white clothes, melting air, ochre-colored dunes and the ubiquitous sun.
And if it is unbearably hot on the sands during the day, at night the desert becomes not just “cool”.
Why is it cold in the desert at night and hot in the daytime?
In the largest desert in the world, the Sahara (about seven million kilometers!) there may even be frosts at night. It’s weird, isn’t it? Let’s figure out why it’s cold in the desert at night? why is this happening?
Deserts are formed where precipitation does not exceed 80 millimeters per year. By the way, the fact that deserts are covered with sand is a misconception. In fact, most of them have rocky surfaces, strewn with gravel. In other words, the air and soil in the resulting wasteland are very dry. Because of this, there is practically no water vapor above the desert itself.
Camels and a guide in the Sahara
So, what’s going on?
During the day, the sun heats the surface of the desert. Due to the actual absence of clouds and the sparse flora, there are no shadows, so the rays actively affect the sand and stones, which are heated. Since the soil is dry, its heat capacity and thermal conductivity are low, the surface area heats up.
Night Sugar
Night falls and the sand with a rocky surface cools down quickly – the heat evaporates, and there is nowhere for it to linger, since the air is dry, not humid. There is no greenhouse effect, so heat leaves the earth very quickly, and cold is the absence of heat. Schematically, this phenomenon was described in the video.
So, if you are going to visit Gobi or Wadi Rum, do not forget to bring water, turban and thermal underwear. Or better yet, take a camel with you – a warm animal will help you move around during the day and protect you from the cold at night. And it’s more fun together..
By the way, sometimes in January 2018, the real snow fell in the Algerian part of the Sahara, which happens only a few times a century.
Snow fell in one of the hottest places in the world
