City welcomes first rime of winter as unique frost appears

The first rime in Jilin city, capital of Jilin province, appeared on Nov 20, as temperatures fell as low as-17 C.

Rime is a special type of frost resembling granular tufts of ice that only occurs in very specific climactic conditions

On Nov 20, all the trees along Jifeng East Road in the city, beside which the Songhua River flows, were coated in a crystal-clear frozen coating. The area quickly attracted residents to take out their phones for a quick frosty snap.

Jilin's rime is known as one of the four meteorological wonders of China. The other three are the sea of clouds of the Yellow Mountain in Anhui province, the sunrise at Taishan Mountain in Shandong province and the tidal bore of the Qiantang River in Zhejiang province.

Compared with rime in other regions in China, rime in Jilin is unique because it is thicker and is extremely crystal clear. A toothpick-thin tree branch can be covered in frost as thick as an adult's thumb, according to local residents.

The best time to observe rime in Jilin is between November and February, and the best observation hours are from 6 am to 10 am. Regions along the Songhua River, Rime Island and Hantun area are best sightseeing places for this rare and spectacular phenomena.

For this unique rime to form, many conditions need to be met, including a heavy snowfall, a breezeless day and a big temperature difference between day and night, according to Zhao Daming, deputy director of the publicity department of Jilin city.

The formation of rime in Jilin city is influenced by the Fengman Hydropower Station upstream of the Songhua River, about 15 kilometers from the city. The hydropower station, which dates back to 1937, was one of the largest of its kind in Asia at that time. A large reservoir, named Songhua Lake, was formed when the hydropower station was built.

In winter, there are more than 60 days when the temperature plunges to-20 C in Jilin city. A thick layer of ice forms on the huge reservoir. However, the water below the ice maintains a temperature above zero. Passing through the turbine generators of the hydropower station, the water temperature further increases, thus the river near Jilin city never freezes in the winter. When all conditions including temperature and humidity are met, rime appears.

The old Fengman Hydropower Station was dismantled in 2018, and a new station about 120 meters downstream was built. Some people were concerned the change might affect formation of rime in 2019. However, the rime reappeared as in previous years.

From Dec 1, a forecast will be provided to visitors about when and where to appreciate the natural wonder.

(China Daily 11/29/2019 page6)