The desert climate zone has the following climatic characteristics:
(1) The precipitation is small and the variability is large: Aswin in the Sahara Desert of North Africa has a record of no rain for many years; In Allica, a desert in northern Chile, South America, there have been only three showers that can measure rainfall in a row 17 years, and the total amount of the three showers is only 0.5 1 cm, so the precipitation is very small. Iquiji, also located in the desert of northern Chile, has no rain for four consecutive years, but in the fifth year, a shower dropped by 65,438+05 cm, and in the second year, a shower record reached 63.5cm, showing great variability. Rainfall in tropical deserts is mostly explosive showers, which often cause serious soil erosion.
(2) High temperature and large temperature difference: Due to less clouds, strong sunshine, insufficient vegetation coverage and low air humidity, the temperature rises extremely rapidly during the day. It is recorded that the temperature in North Africa is as high as 58℃. Generally, the average monthly temperature in summer is between 30℃ and 35℃, and the high temperature lasts for a long time. For example, in Aden, Arabian Peninsula, the monthly average temperature is above 30℃ for five months in a year.
The desert is cooler at night, because there is no cloud all night, and the ground radiation is strong and the heat dissipation is fast. The lowest temperature at night is usually between 7℃ and 12℃, and there are also days of thin frost. The annual temperature difference is generally around 10℃~20℃, and the daily temperature difference is even larger, between 15℃~30℃. At a meteorological monitoring station south of Tripoli in North Africa, 1978,1February 25th, 978, it was recorded that the highest temperature in Jedaias during the day was 37.2℃, but at night, the lowest temperature dropped to -0.6℃, and the daily temperature difference reached 37.8℃, which was really "wearing fur coats in the morning and wool in the afternoon".
(3) Strong evaporation and low relative humidity: The tropical desert climate has strong evaporation because it is often cloudless, windy, sunny, high temperature and low relative humidity in Wan Li. The possible evapotranspiration is 20 times or even about 100 times of precipitation. The relative humidity in the air is very small, and it often appears at about 2% in the Sahara desert of Egypt.
Desert climate is the extreme situation of continental climate. It is the most widely distributed in the subtropical desert. The basic reason is that there is little rain, plants are difficult to survive, and the species and quantity of plants are extremely rare. The ground is bare, the air is very dry and there is little moisture. During the day, the solar radiation is strong, and the ground temperature rises rapidly, and the temperature can reach 60 ~ 70℃. The updraft is strong, but because the air is dry, there are few clouds and little rain, only strong winds and dust. On the ground at night, the temperature drop is extremely strong, even below 0℃. Therefore, the temperature varies greatly every day. Can be as high as above 50 DEG C..
The Sahara desert is the largest desert in the world, and the tropical desert climate is also the most typical. The weather is very dry and hot. In most areas, the average annual rainfall is below 50 mm, and some places even have no rain for many years. This is the driest climate type on earth. Extreme heat is a masterpiece of desert. The absolute maximum temperature can exceed 50℃, and the ground temperature is higher.
The hottest place in the world appears in the Sahara desert, so it is no wonder that laying eggs in the Gobi desert has become an explorer's specialty. China also has "three stoves", but they are dwarfed by them. In this harsh climate, the fittest survive, and there are very few creatures that can survive. Only those dwarf plants and thirsty animals can become the masters of the desert kingdom.