吉林省季节冻土区年冻融指数的时空变化特征

利用1961 - 2015年吉林省46个气象站的气象数据， 采用气候诊断分析方法， 研究了吉林省季节冻土区年冻融指数的时空变化特征及其与经度、 纬度、 海拔的关系。结果表明： 吉林省冻结指数呈由北向南逐渐降低， 融化指数由西向东逐渐降低的趋势分布。1961 - 2015年冻结指数呈显著下降趋势， AFI（空气冻结指数）和SFI（地表冻结指数）气候倾向率分别为-48.7 ℃·d·（10a）^-1和-166.8 ℃·d·（10a）^-1。融化指数显著上升， ATI（空气融化指数）和STI（地表融化指数）分别以57.0 ℃·d·（10a）^-1和93.7 ℃·d·（10a）^-1的气候倾向率显著上升。SFI、 ATI和STI分别于2001年、 1994年和1997年发生了突变。20世纪60、 70年代冻结指数异常偏高， 融化指数异常偏低。吉林省年冻融指数的变化趋势在未来整体上依然延续下去， 即冻结指数为下降趋势， 融化指数为上升趋势。冻结指数受纬度影响最大， 随着纬度的升高而上升， 融化指数受海拔影响最大， 随着海拔的升高而显著下降。冻结指数气候倾向率随着海拔的升高而上升， 融化指数气候倾向率随着纬度的升高而上升。

Spatiotemporal changes of annual freezing/thawing index of seasonally frozen soil in Jilin Province

Based on the meteorological data from 46 meteorological stations in Jilin Province from 1961 to 2015， the spatiotemporal changes of annual freezing/thawing index and its relationship with longitude， latitude， altitude were studied by the method of climatic diagnosis analysis in Jilin Province. The results showed that the freezing index had decreased gradually from north to south， and the thawing index had decreased from west to east in the province. The freezing index showed a significant downward trend， with the climatic tendency rates of AFI （air freezing index） of -48.7 ℃·d·（10a）^-1 and SFI （surface freezing index） of -166.8 ℃·d·（10a）^-1. The ATI （air thawing index） and STI （surface thawing index） increased significantly at 57 ℃·d·（10a）^-1 and 93.7 ℃·d·（10a）^-1， respectively. The SFI， ATI， and STI had mutated in 2001， 1994， and 1997， respectively. In the 1960s and 1970s， the freezing index was very high and the thawing index was extremely low. The trend of freezing thawing index in the future was consistent with the past， when the freezing index had an downward trend and the thawing index had an upward trend. The freezing index was mainly affected by latitude and increased with the rise of latitude. The thawing index was mainly affected by altitude and decreased significantly with the rise of altitude. The climatic tendency of freezing index increased with the rise of altitude， and the climate tendency of the thawing index increased with the rise of latitude.