Why does it rain so often in Lhasa?

Last week I reviewed the Qinghai-Tibet region of China’s regional geography and found that the city of Lhasa is very interesting. The reason is that it is known as the Sunlight City, but it is not the season with the most sunshine in summer. People who have been to Tibet before will say this It is believed that Lhasa is sunny and cloudless during the day, but it rains heavily at night; on the next day, it is still sunny during the day, and it rains heavily at night. This should be the appearance of the Buddha to take care of the pilgrims who have gone through all the hardships to reach the plateau. , tourists or tourists, so that they can see the true face of Lhasa and gain a happy and good mood. Buddha generally exists in the hearts of people with faith. I prefer to find it from a geographical perspective. The city of Lhasa, according to the weather The data reflects that the annual precipitation is more than 400 mm, which cannot be called a drought, but can even be called humid. At the same time, Lhasa is known as the Sunlight City, but it has many sunny days. After checking the data, it was found that Lhasa’s sunny days and rainy nights are due to Tibet’s unique nature. terrain conditions. Because Tibet is full of plateaus and slopes, and cities and towns are built in river valleys close to water sources. Lhasa is located in the Lhasa Valley. On the Tibetan Plateau, the 24-hour temperature change a day is significantly affected by solar radiation heat. At the same time, Due to the large altitude difference between hillsides and valleys, the temperature differences at different altitudes at the same time are also very obvious. The higher the altitude, the lower the temperature. During the tourist season in Tibet, the plateau is subject to the strong radiation of the local strong sun every morning. The earth absorbs the radiant heat of the sun, and the temperature is generally rising. After noon, the temperature of the earth rises to its peak. From the afternoon, the radiant heat absorbed by the earth from the sun gradually decreases, and the rate of heat dissipation by the earth gradually accelerates. At this time, the high mountain slopes begin to cool down first, and the atmospheric temperature at the same altitude as the mountain slopes also decreases. The air becomes cooler, becomes denser, and the weight of the air becomes heavier and gradually decreases. The air at high altitudes cools and drops over the valleys at low altitudes. The warm, moist air originally in the valleys is less dense and lighter, and begins to rise under the squeeze of the cold air falling from the high slopes. When the warm and humid air continues to rise and reaches a certain height, the moisture in the air begins to condense into countless tiny water droplets suspended in the air. These are clouds. The cold air on the high slopes continues to fall, and the warm and humid air in the valley continues to be lifted; the warm and humid air continues to rise and condense small water droplets, so the clouds accumulate thicker and thicker; more and more small water droplets are condensed, and they interact with each other. The water droplets gathered together, and the water droplets gathered bigger and bigger. Finally, the rising air current could no longer hold the water droplets that were getting bigger and bigger. These water droplets could no longer be suspended in the air and fell downwards. Then it started to rain. It takes a long time for the dry and cold air on the high slopes to descend, and the warm and humid air in the valley to rise, until the warm and humid air condenses into clouds, and cumulus clouds turn into rain. It usually starts in the afternoon and continues until the evening, until it rains. It's night time. A burst of night rain often brings down all the moisture in the sky in the form of raindrops. By the next morning, it is cloudless and the sun is shining brightly again. This kind of weather with sunny days and rainy nights due to the terrain of high slopes and river valleys with an altitude difference of several thousand meters mainly occurs in summer, the prime tourist season in Tibet. This kind of good tourism weather that benefits from the plateau terrain is not only found in Lhasa, but also in other towns built in river valleys in Tibet. If you travel to Shigatse, Tibet, you will also encounter this kind of good weather with sunny days and rainy nights.