关键词: 冰冻现象, 霜日, 积雪日, 结冰日, 雾凇日, 雨凇日, 趋势

Abstract: Gelivation weathers, including frost, snow-cover, ice-cover, rime, glaze, etc. are catastrophic climate events. Scientists pay more attention to their climatic effects, because the agriculture, forestry, transportation, electric supplying, communication and people's diet become more sensitivity in the gelivation weathers. Based on the daily observations of the gelivation weather phenomena at more than 1 600 stations, the five kinds of primary gelivation weather characteristics in China from 1960/1961 to 2011/2012 are analyzed. The result shows that the yearly averaged frost weather more than 180 days occur mainly in the northeast of the Tibetan Plateau, Tianshan Mountains and the Greater and Lesser Xingan Mountains. Frost day has a linear increasing trend in the northern Central China and the Tibetan Plateau, and a decreasing trend in Yangtze River basin and its south. It is an evident increasing trend of the nationwide averaged frost days, which has passed through the test at 0.05 significance level, with an increase rate of 2.03 d per 10a, so the frequency of frost days is increasing. The yearly averaged snow-cover duration more than 90 days occurs mainly in the northeastern Tibetan Plateau, Tianshan Mountains and the Greater and Lesser Hinggan Mountains. There is no evidently linear trend of snow-cover days. The yearly averaged ice-cover duration more than 210 days occurs mainly in the Tibetan Plateau, Greater Hinggan Mountains and parts of the Tianshan Mountains. The nationwide ice-cover duration is mainly decreasing. The nationwide averaged ice-cover duration has evident decadal variation; the longest one was from 1980 to 1990. The yearly averaged rime duration more than 30 days mainly takes place in the Tianshan Mountains, the Greater Hinggan Mountains and the Emei Mountain. The rime duration in China is mainly decreasing linearly, with a partial increase in the Yangtze River basin. The nationwide averaged rime duration is evidently decreasing with a rate of 0.60 d per 10 a, and passing through the test at 0.01 significance level. Galze mainly occurs in Yunnan-Guizhou Plateau and a few high mountains in the middle and lower reaches of the Yangtze River. The galze duration is mainly decreasing linearly in North China Plain, with a partial increase in parts of the middle and lower reaches in the Yangtze River. The nationwide averaged galze duration has a faintly increasing.

Key words: gelivation weathers, frost duration, snow-cover duration, ice-cover duration, rime duration, glaze duration, trend