Snow mountain is obviously closer to the sun, why is the temperature lower above it?

Mount Qomolangma is the highest peak in the Himalayas and the highest peak in the world, and half of it is located on the Qinghai-Tibet Plateau in China. At present, it is recognized that the height of the rock surface of the mountain peak is 8844 meters, and the height including snow is 8848 meters. Many climbers are proud of climbing Mount Everest. The interior of the earth can be divided into three layers: the core, the mantle and the crust. The earth's surface has been moving slowly, and the crust can be divided into six plates according to related characteristics. The Asia-Europe plate and the Indian Ocean plate pressed against each other, forming the Himalayas and the Qinghai-Tibet Plateau, with the whole Himalayan mountain as high as six or seven kilometers. Mount Qomolangma was also formed by the slow uplift under the compression of two plates.

Mount Everest is located in the north temperate zone, and its peak is covered with snow about several meters thick. Because of the high altitude, the air at the top of the mountain is very thin, and the atmospheric pressure is only 1/3 of the surface, so the water content in the air is also very low. The snow on Mount Everest is accumulated over the years. The highest temperature of Mount Everest in summer is still below 0 degrees, and the snow will not melt. The height of snow line on the south slope is lower than that on the north slope. This is because the south slope is located on the windward side, and the warm and humid airflow from the Indian Ocean is relatively cold, resulting in more snowfall, and the precipitation on the south slope is richer than that on the north slope. In addition to temperate mountains, there are also snow on high-altitude peaks near the tropical equator, such as the peak of Kilimanjaro (located in Kenya, Africa) near the equator.

In our daily experience, the stronger the solar radiation, the higher the ambient temperature. Closer to the sun (high altitude) and direct sunlight (low latitude), the temperature should be higher, but there is snow in the mountains near the equator. In fact, there is snow all the year round in mountainous areas above 5 kilometers above sea level all over the world. Why the higher the altitude, the lower the temperature? In fact, the temperature decreases with the elevation, which only applies to the troposphere. The atmospheric temperature in the stratosphere will gradually increase with the elevation.

When the sun shines on the earth's surface through the atmosphere, it will warm the earth's surface, and the ground will radiate heat to the atmosphere in the form of long waves (invisible infrared rays). Under the action of the earth's gravity, the atmospheric density presents a gradient distribution, and the surface temperature naturally presents a gradient distribution. The higher the altitude, the lower the atmospheric density and the lower the temperature. The surface air receives more and denser ground radiation, and the natural temperature is higher. There is snow all the year round at high altitude, and the reflectivity of snow to solar light is very high, which makes the surface absorb less sunlight, and the temperature is naturally much lower than that near sea level. Some people may think it is a joke that Mount Everest is closer to the sun. Taking the Qinghai-Tibet Plateau in China as an example, the solar radiation received in this area is much stronger than that in other parts of the country, mainly because of its low latitude, high altitude and thin air. During the day, the solar radiation is strong and the temperature is very high; At night, due to the thin air and poor thermal insulation, it will become extremely cold. Tibetan robes are related to the large temperature difference between day and night in plateau areas.