Deserts are famous for being scorching hot during the day … but when it comes to the night it’s a whole different story! The temperature gets so freezing that it feels like the middle of winter. The only thing missing is snow. In the Sahara, for example, it can be minus 4 ° C at night, while the temperature during the day is around 40 ° C! How can one explain such a phenomenon? Reply!
In general, the cause of this day / night temperature difference in the deserts remains pretty obvious: the sand. Indeed, it should be known that the grains of sand absorb and give off heat in the air during the day, which explains the searing temperature when the sun is high in the sky … but once that is down, is it gone all those ovens?
The sand is to blame …
Imagine sand doesn’t hold the heat very well when it’s dark. The latter quickly radiates into the air as soon as the sun has disappeared in the sky. As a result, the atmosphere suddenly turns from scorching to freezing! But of course the properties of sand do not explain everything, because the fault also lies in the lack of humidity in the deserts. Dry air does not contain water vapor and this stores the heat during the night!
A difficult environment
It is clear that life in the desert with its scorching days and freezing nights is not that easy. Fortunately, the plants and animals that live there have found a way to adapt to such a difficult environment. Reptiles, for example, can withstand extreme temperature fluctuations thanks to their “ectothermal” organism. This means that you can maintain a constant body temperature without having to invest energy.
Reptiles, for example, can withstand extreme temperature fluctuations thanks to their “ectothermal” organism. Screenshot of the NASA website.
Large mammals, on the other hand, maintain this famous constant body temperature by drawing energy from their fat or by protecting themselves from the cold with their thick fur. Then desert birds use a mechanism similar to transpiration to withstand dry temperatures. This parade, known as “evaporative cooling”, consists of using water to draw heat away from the body (for example, vultures pee on each other to cool their paws …).
After all, plants are most susceptible to extreme temperature changes in the desert because they cannot move. Suddenly those who are in the coldest zones at night do not manage to survive much longer. This is because the water in their tissues freezes and damages them. Therefore, the flora is only abundant in certain places in the desert. In these areas, the air temperature does not drop below zero and therefore remains viable.