博州农区近50年终霜冻的变化趋势

利用博州农区3个气象站1958-2007年的终霜冻观测资料，分析了其变化趋势。结果表明：博州不同地区终霜冻出现时间差异较大，温泉地区较博乐、精河地区分别偏早15d、20d；在博州自东向西随着海拔高度的增加，终霜冻的变幅增加，不稳定性增加；博州农区终霜冻的变化均呈提前趋势，博乐、精河、温泉三地又以博乐最为明显，提前速率为0.17d／a；博州农区终霜冻的变化具有明显的阶段性；博州三地终霜冻年际变化均具有4-5a、15a的振荡周期，而温泉还具有不同于其他两地的35a振荡周期。

The Variety Trends of Latest frost in Agriculture area of Boertala Prefecture in 1958-2007

Based on data observed at three meteorological stations in Bortala from 1958 to 2007, the trend of latest frost has been statistically analyzed in this paper. It is found that the occurrence of latest frost changes significantly in different areas. The latest frost occurred 15 and 20 days earlier in Wenquan than in Bole and Jinghe. The amplitude variation and the instability of latest frost were increased with the increased height from east to west in Bortala. The latest frost in agriculture area of Boertala＇s three county above were presented a trend of advance without exception, and Bole to be obvious particularly with an advance rate of 0.17 d/a. The variety of latest frost in agriculture area of Boertala demonstrated distinct stage. The interannual variation of latest frost had a varying period of 4-5a or 15a in the three areas, and there is an additional period of 35 years in Wenquan.