中国西北地区1961~2009年无霜期的气候变化特征

Characteristics of the Frost-Free Season Changes from 1961 to 2009 in Northwest China

摘要:

利用中国西北地区135个测站，1961~2009年历年逐日地面最低气温和平均气温资料，采用线性趋势分析、Mann-Kendall、子波分析、功率谱分析和合成分析等方法，分析了近49 a中国西北区无霜期的气候变化特征。结果表明：1) 中国西北地区无霜期最长的地方在陇南–陕南，平均220 d以上，其次塔里木盆地和吐鲁番地区平均200 d以上。无霜期最短的地方主要在青海高原，一般不足3个月。北疆－河西走廊120 d~140 d，甘肃河东–陕北150 d~160 d。2) 西北地区无霜期平均以3.8 d/10 a的速率增加，1987年有明显的突变现象。近49年来无霜期有显著的3年周期；3) 西北地区有90%的站点以2~5 d/10 a的速率延长。通过各年代际的变化来看，1960~1970年代大多数地方无霜期偏短，1980年代开始增加，1990年代有58%的站偏长，近10年，有92%的站无霜期偏长；4) 受气候变暖影响，寒冷日数减少，终霜冻提前，初霜冻推迟，无霜期延长。但对无霜期的贡献，终霜冻高于初霜冻。

Abstract: Using the daily surface minimum air temperature data of 135 observational stations from 1961 to 2009 in Northwest of China and average temperature data, with the methods linear trend analysis, Mann-Kendall, Moving T-examination, wavelet analysis, power spectrum and so on, analyzed climatic variation characteristics of the frost-free season of Northwest China in recent 49 years. The results show that: 1) The frost-free season is the longest place in South Gansu, South Shanxi which has 220 days, and next is South Xinjiang Basin which has 210 days. The frost-free season is the shortest place in the Qinghai Plateau which is shorter than for three months. Other place, It has about 120 d - 140 d in northern Xinjiang-Gansu Corridor and 150 d - 160 d in Gansu East of the river, North Shaanxi; 2) The average frost-free season postpone at a rate of 3.8 d/10 a, whole area postpone 18 days. There is an abrupt change in 1987. The frost-free season have the remarkable 3 year periods in recent 49 year; 3) There are 90% stations that the frost-free season postpone, and majority area postpone by speed of 2 - 5 d/10 a. Looked through the interdecadal climatic trends, since 1980 ages have 50% above station to be increase, especially in the recent 10 years, have the close 92% station to be increase; 4) Is changed the climate warm influence , the cold date number reduces, the last frost ahead of time, the first frost postpone, the frost-free season lengthens. But to the frost-free season contribution, the last frost is higher than the first frost.