But in some seasons, there will be many clouds, which all look very low, and there is still a blue sky between the clouds.
1, the reason for the blue sky in Lhasa:
When sunlight enters the atmosphere, long-wavelength colored light, such as red light, has great transmission power and can penetrate the atmosphere and shoot to the ground; However, violet, blue and cyan light with shorter wavelength will easily scatter when it touches atmospheric molecules, ice crystals and water droplets. Scattered purple, blue and cyan light fills the sky, making it appear blue.
2. Location of Lhasa
Lhasa is located in the southeast of Xizang Autonomous Region, on the north bank of Lhasa River, a tributary of Yarlung Zangbo River. Its geographical coordinates are 9 106' east longitude and 29 36' north latitude. The administrative area of the city spans 277 kilometers from east to west and 202 kilometers from north to south, with a total area of 295 18 square kilometers.
3. Climate characteristics
The climate belongs to the semi-arid monsoon climate zone in the temperate zone of the plateau. The annual sunshine hours are 3,000 hours, which is more than 1.800 hours in Chengdu, Sichuan, and more than 1.654 38+0 hours in Shanghai, the largest city in eastern China. It ranks among the best in China, so it has the reputation of "Sunshine City".
Where is Lhasa located? Affected by the downdraft, the northern side of the Himalayas is sunny all year round, with little rainfall, no severe cold in winter and no heat in summer, which belongs to the semi-arid monsoon climate in the temperate zone of the plateau. The highest temperature in history is 29.6 degrees Celsius, the lowest temperature is minus 16.5 degrees Celsius, and the annual average temperature is 7.4 degrees Celsius. Rainfall is concentrated in June, July, August and September, and the sunshine time is more than 3,000 hours. It is known as the "Sunshine City".
The annual precipitation is 200-5 10 mm, concentrated in June-September, and it rains many nights, which is called rainy season. Strong solar radiation, thin air, low temperature, large temperature difference between day and night, cold, dry and windy in winter and spring. The annual frost-free period is 100 ~ 120 days.
4. Topography
Lhasa is located? The central part of the Qinghai-Tibet Plateau is 3650 meters above sea level and is one of the highest cities in the world. Its terrain is high in the north and low in the south, and it slopes from east to west. The south-central part is the valley plain in the middle reaches of Lhasa River, a tributary of Yarlung Zangbo River, with flat terrain.
Nyainqentanglha stands at 100 km north of Lhasa. Big Snow Mountain, North Edge? Namco, the highest point of the mountain is 7 1 17 meters above sea level. Nianqing? Where does Mount Tanggula stand? The central part of the Qinghai-Tibet Plateau, about 600 kilometers from west to east, is bordered by Gangku Kasai in the west, and extends to the southeast to meet Boshula Mountain in Hengduan Mountains, with the central part slightly protruding to the north. It is the Yarlung Zangbo River. The watershed of the Nujiang River divides Xizang Autonomous Region into three regions: northern Tibet, southern Tibet and southeastern Tibet. The Great Tanggula Pass is 523 1 m above sea level, which is the natural dividing line between Qinghai Province and Tibet Province. Qinghai-Tibet line? Highest point of national highway 109. "Nyainqentanglha" means "the spirit should be the god of grassland" in Tibetan. These four peaks and their surrounding areas suffered from strong Quaternary glaciation, resulting in steep? Mountains, especially the northwest slope, are steep and abnormal.