1961—2015年吉林省霜时空分布特征及其影响因素

Spatial and temporal distribution characteristics and impact factors of the frost over Jilin province from 1961 to 2015

利用1961—2015年吉林省50个气象站霜的观测资料,采用线性倾向估计、Mann-Kendall突变检验和Morlet小波分析等方法,分析了吉林省霜的时空变化特征及其与气候因子、地理因子的关系。结果表明:1961—2015年吉林省初霜日显著推迟、终霜日显著提前且无霜期显著延长,气候倾向率分别为1.4 d/10 a、-2.2 d/10 a和3.6 d/10 a。初霜日显著推迟的气象站占全省站点总数的58%,终霜日显著提前的气象站占60%,无霜期显著延长的气象站占72%。20世纪60年代吉林省初霜日最早,20世纪70年代终霜日最晚;20世纪70年代无霜期最短,2011—2015年无霜期最长。从空间分布来看,吉林省初霜日自西向东逐渐提前,终霜日自西向东逐渐推迟,无霜期自西向东逐渐缩短。近55 a吉林省终霜日和无霜期分别在2009年、2000年发生突变,初霜日、终霜日和无霜期的主周期均为3 a左右。随着海拔高度和经度升高,初霜日提前,终霜日推迟,无霜期缩短;随着纬度增加,终霜日提前,无霜期延长。吉林省初霜日和无霜期主要受9月气温与0 cm地温影响,终霜日主要受5月气温和0 cm地温影响。

Based on the frost observation data of 50 meteorological stations over Jilin Province from 1961 to 2015,the spatial and temporal distributions of the beginning and ending frost date,frost-free period and their relationships with climatic and geographical factors were analyzed using the methods of a linear trend estimation,a Mann-Kendall test and a Morlet wavelet analysis. The results show that the beginning frost date is postponed and the ending frost date occurs earlier. The frost-free period becomes significantly longer. The climatic trend rates for the beginning and ending frost date and frost-free period are 1. 4,-2. 2 and 3. 6 days per decade, respectively. The number of stations with delayed beginning frost date accounts for 58% of the total stations, that of ahead of ending frost date is 60% and that with longer frost-free period is 72% of the total stations. The earliest beginning frost date occurs in1960 s. The latest ending frost date is in 1970 s. The shortest frost-free period appears in the 1970 s and the longest frost-free period happens during 2011-2015. In terms of the spatial distribution, the begining（ ending） frost date and the frost-free period are gradually ahead of time（ postponed） and shortened from the west to the east of Jilin.The time series of the ending frost date and the frost-free period show climatic abrupt changes in 2009 and 2000,respectively. The main cycles of the beginning and the ending frost date and the frost-free period are all about 3 years. In addition, the beginning and ending frost date and the frost-free period are ahead of time,postponed（ ahead of time） and shortened（ prolonged） with the increasing longitude and altitude（ latitude）, respectively. The beginning（ ending） frost date and the frost-free period are mainly affected by the climatic factors in September（ May）, respectively.