Photo taken on Jan. 31, 2018 shows sea ice along the coastal area of Beidaihe District in Qinhuangdao, north China's Hebei Province. (Xinhua/Yang Shiyao)

Photo taken on Jan. 31, 2018 shows sea ice along the coastal area of Beidaihe District in Qinhuangdao, north China's Hebei Province. (Xinhua/Yang Shiyao)

Photo taken on Jan. 31, 2018 shows sea ice along the coastal area of Beidaihe District in Qinhuangdao, north China's Hebei Province. (Xinhua/Yang Shiyao)

Photo taken on Jan. 31, 2018 shows sea ice along the coastal area of Beidaihe District in Qinhuangdao, north China's Hebei Province. (Xinhua/Yang Shiyao)

Photo taken on Jan. 31, 2018 shows sea ice along the coastal area of Beidaihe District in Qinhuangdao, north China's Hebei Province. (Xinhua/Yang Shiyao)