重庆入春日期时空分布规律研究

利用重庆1966-2008年34个站逐日平均气温资料,计算出各站近43年逐年的入春日期,运用EOF、REOF、趋势分析及Morlet小波分析等方法进行了时空分布特征分析。结果表明,重庆地区入春日期的空间差异大;一致性异常特征是重庆地区入春日期的最主要的空间模态,而高、低海拔反向变化模态也是比较重要的;重庆地区入春日期可分为西部型、中部型、东南部型及长江沿线型4个主要的空间分布型,各主要空间分区的年际变化特征不一致,主要表现为弱的提前趋势型和抛物线型;近43年来入春日期各分区的周期振荡不完全一致。

Study on Temporal-Spatial Features of the Date of the First Day to Spring in Chongqing

By using the daily mean temperature data in 1966-2008 from 34 stations in Chongqing,the annual dates of the first day to spring for various station in the recent 43 years were calculated,and the temporal-spatial distributions were studied using the methods of EOF、REOF、tendency analysis and wavelet analyses.The results show that spatial distributions of the dates of the first day to spring display clear differences.The consistently abnormal characteristic is the main spatial distribution mode of the dates of the first day to spring in Chongqing,and it is also the important mode that the high and the low altitude areas are reverse change feature.The dates of the first day to spring in Chongqing are divided into four spatial distribution types: the western type,the middle type,the southeastern type and the Changjiang River coastal area type.The characteristic of interannual change in every sub-area is inconsistent,and it shows two types mainly: slightly earlier trend type and parabolic curve type.In the recent 43 years,the periodic oscillations of the dates of the first day to spring are not well consistent in every distribution type.