张家口市≥0℃积温变化特征分析

Analysis on Change Characteristics of Boundary Temperature(≥0 ℃) in Zhangjiakou City

根据张家口市1960—2011年逐日气温资料,运用线性倾向估计等方法计算分析了≥0℃积温的时间变化特征。结果表明:52年来年平均气温呈增加趋势,线性增温率为0.42℃/10年,1983年后气温显著增加。≥0℃积温呈增加趋势,增温率为89.4℃/10年。≥0℃初始日期呈显著提前趋势;终止日期呈延迟趋势,且持续天数增加明显。≥0℃终日延迟程度大于起始日期提前程度。

Based on the daily temperature of Zhangjiakou City from 1960 to 2011 ,the characteristics of accumulated temperature change of ~〉0 ~C was analyzed by using the methods of linear trend estimates. The results indicated that ：The annual temperature showed an increasing trend with the linear warming rate of 0.42 ℃/10 a during the past 52 years. After 1983 ,the warning trend increased significantly. ≥0 ℃ accumulated temperature showed an increasing trend with the warming rate of 89.4 ℃/10 a. The trend of initial date of ≥0 ℃ appeared ahead ,while the terminal date was delayed ,so the sustained days of the boundary temperature increased significantly. In the past 52 years ,the delay of the terminal date of the boundary temperature was greater than the ahead of the initial date.