This article is reprinted with permission from WeChat Public Planet Research Institute, Photo by Ray Hennessy on Unsplash < / strong>
China’s snow season has arrived, and the people shouted in their hearts: Come on
Yak in the snow, photographer @ 卢 文
Down it
Tibetan fox in the snow, taken in Hoh Xil, photographer @ 张强
Down it
Wolf in the snow, taken at Inner Mongolia, photographer @ 宾 果
From high mountains to plains, from cities to countryside. People enjoy snow and play snow, showing extreme excitement.
Tibet wild donkeys striding in the snow, photographer @ 卡布; the above animal pictures are anthropomorphic expressions, which does not mean that snowfall is beneficial to the survival of animals Influence
But meteorologists tell us: Heaven and Earth are reluctant to show people snow easily.
According to statistics for decades, in densely populated North China, average annual snowfall days only 5 ~ 10 days, the middle and lower reaches of the Yangtze River > The area is only 3 days. Only the sparsely populated Qinghai-Tibet Plateau and Northern Xinjiang and Northeast can reach dozens of days.
China’s average annual snowfall days, excluding sleet, charting @ 郑伯容 & 龚向杰 / 星球 学院
The number of snowfall days is so limited. It is no longer snow, but luck, true love, and rare treasures. ,
So how can we have a snow country?
01 Southern Snow
In the winter, Siberia in the north and other places send us cold air, the surrounding ocean sends us water vapor . Water vapor condenses into ice crystal
, the ice crystals continue to condense and grow, becoming snowflakes.
Snowflakes, pictures from @ 视 中国
When the snowflakes fall, if the temperature under the clouds is higher than 0 ° C, which causes the snowflakes to melt or partially melt, rainfall or sleet will form.
Schematic of sleet formation, mapping @ 星球 学院
If the temperature below the cloud is below 0 ° C, it will fall to the ground in the form of snowflakes to form a real snowfall.
Snowfall, taken in Xi’an, photographer @ 孙 岩
It can be seen that in order to form snowfall, various conditions such as cold air , water vapor , under-cloud temperature are necessary.
Latitudes south of 25 ° in China, including central and southern Yunnan, most of Guangxi and Guangdong, and coastal areas of Fujian, Taiwan, and Hainan have low latitudes, and cold air is difficult to reach. 4000 meters away from Yushan and other small mountains are all snow-free zones.
Cloud