近50 a齐齐哈尔市极端气候事件特征分析

Analysis of Qiqihar Extreme Climate Events During 1951～2006

利用目前国际上较流行的极端气候指数方法对1951～2006年齐齐哈尔市24种极端气候指数进行计算和分析,得到了齐齐哈尔市极端气候事件的事实和变化特征。结果表明:齐齐哈尔市的年最低气温、暖夜、热夜日数和生长季长度呈显著上升趋势;冷夜、冷日、霜日、冰日和日平均温差均呈显著下降趋势。各种降水指数的变化趋势都不显著;极端气温和降水指数均存在阶段性特征和突变特征;最低气温的增暖主要发生在20世纪80年代中期以后,而最高气温则在90年代以后变暖明显,夜间气温的上升对增暖进程的贡献更大;极端降水事件的强度和频率呈增加趋势,2000年以后增加趋势尤为明显。

Based on the extreme climate indices, 24 indices of Qiqihar during 1951-2006 are evaluated, the extreme climate events and their variations are obtained. Results show that in the recent 50 years, yearly minimum temperature （TNN）, warm nights （TN90）, tropic nights（TR） and growing season length（GSL） have the significantly increasing tendency, while cold nights （TN10）, cold days （TX10）, frost days（FD）, ice days（ID） and mean daily temperature difference have the decreasing tendency. Changing trend of the all precipitation indices have not Significant level. There are phase and abrupt change characteristics in the extreme temperature and precipitation indices. The TNN warming occurs mainly after mid-1980s, while the maximum temperature （TXX） has the marked increasing tendency after 1990. The rising of night temperature contributes much to the warming. The intensity and frequency of extreme precipitation events present rising tendency, especially after 2000.