近46年中国冬季日均气温及极端温度的变化

应用1961—2006年我国599个站的冬季逐日平均温度资料，分析了冬季各月最低（高）日均温度、低温日数及三种极端温度指数的变化趋势。结果表明冬季各月最低、最高温度的变化均呈明显上升趋势，2月份升温最显著，日均气温低于5℃的冷日数和日均气温低于-10℃的严寒日数在冬季各月都是减少的。全国近46年冬季极端低温日数呈明显减少的趋势，1986年出现一次跃变，2006年最少；极端高温日数普遍增加，1995年出现跃变，1998年达到峰值；霜冻日数在27°N-46°N间区域显著减少，跃变点在1987年，最低值出现在1998年。

Variations of Winter Daily Average Temperature and Extreme Temperature in the Recently 46 Years in China

On the basis of 46-year winter daily temperature data from 596 weather stations in China, this paper analyzed the minimum and maximum average daily temperature, cold and extreme-cold days and 3 indices of extreme temperature changes. The results show that： in the recently 46 years, the minimum and maximum temperatures in winter every month are obviously on the rise, February being most obvious. The cold days that daily average temperature is below 5℃; and the extreme-cold days that daily average temperature is below - 10℃ reduce in winter and every month in winter. The frequency of winter extreme low-temperature events is reducing obviously in the recently 46 years in China, with a jump change in 1967 and a valley in 2006. The winter extreme low-temperature events are increased, with a jump change in 1995 and a peak in 2006. The frost days are reducing obviously in the 27°N - 46° N, with the jump change time and the valley value separately appearing in 1987 and 1998.