Why is Tanggula so cold?

Tanggula is the section of Qinghai-Tibet Railway with the worst climate, the worst geological conditions and the most difficult construction. Slope wetlands are widely distributed, with long frozen soil section, high ground temperature, large ice content and strong frost heaving and thawing settlement; There are island permafrost and deep seasonal permafrost in the south of Amdo. In winter and spring, the temperature is very low and the wind is very cold. In July and August, the weather was a little warmer, and there was plenty of rain. A cloud floated by, either rain or snow or hail. The Qinghai-Tibet Railway starts from Tanggula Pass and is no longer parallel to the highway. Instead, it takes the no-man's land and goes straight to Amdo County, Xizang Autonomous Region.

The Great Tanggula Pass is 523 1 m above sea level, which is the natural dividing line between the two provinces of Qinghai-Tibet and the highest point of the Qinghai-Tibet Line 109 National Highway. The top of Tanggula Mountain is covered with snow all year round, and dozens of ancient glaciers are running freely, which can be described as "the mountain is near and the river is far away". Here you can also see the mysterious four scenes of a day. Most tourists come and go here to stay, take photos and enjoy the scenery. Crossing the Great Tanggula Pass, there is a small Tanggula Pass at an altitude of 50 10 meters ahead. After that, I entered the Qiangtang Plateau in Tibet, surrounded by snow-capped mountains, blue sky and grasslands, and cattle and sheep were scattered in green fields like pearls. The oxygen content in the air here is only 60% of the horizontal line. Ordinary passengers passing through Tanggula Pass will have obvious altitude sickness.

The railway is a line with the highest elevation of 5072 meters, which is lower than the highest elevation of Qinghai-Tibet Highway by 159 meters, and the geological conditions are relatively good. Tanggula Station is designed as a three-lane comprehensive station for both passenger and cargo. It is the highest intermediate station along the Qinghai-Tibet Railway and the highest railway station in the world. The waiting room is equipped with large-scale oxygen making equipment.

The 109 highway (i.e. 2 1 work area) at 3352km of Qinghai-Tibet Railway is nearly 5100m above sea level, which is responsible for the maintenance of Tanggula Pass. It is the highest among the 36 work areas along the Qinghai-Tibet Highway from Golmud to Lhasa, and is known as "the first road class in the world".