摘要
利用美国NCEP再分析月平均资料及我国华北地区2 6个测站月降水资料,采用奇异值分解(SVD)方法,研究了华北降水的年代际和年际变化特征与北半球大气环流的联系.结果表明,首先对降水和大气变量资料作相应时间尺度的分离是非常必要的,否则所得到的SVD结果不能反映年代际变化特征而只能反映年际变化特征;华北降水年代际和年际变化对应的大气环流异常有明显的差异;对应发生在2 0世纪70年代后期华北降水的一次年代际跃变,环流场均存在明显的跃变,而且有一个从地面向对流层上层传播的过程.
With the data of monthly precipitation of 26 stations in North China and American NCAR/NCEP monthly reanalysis atmosphere variables, by method of Singular Value Decomposition (SVD), we have investigated the variation features of precipitation in North China at interdecadal and interannual time scales, and also its relation with the atmospheric circulations in the Northern Hemisphere. The results show that it's necessary to do time scale separations to precipitation and atmosphere variables, otherwise, the outcomes of SVD reflect only the characteristics of interannual time scale without interdecadal time scale. Corresponding to interdecadal and interannual time scales of precipitation in North China, there exist significant differences in the anomalies of atmospheric circulations. In connection with the remarkable interdecadal shift of precipitation occurring in the late 1970s in North China, all the atmospheric circulations have the same shift as well, together with a propagation process from ground surface to the upper troposphere.
出处
《地球物理学报》
SCIE
EI
CAS
CSCD
北大核心
2005年第3期511-518,共8页
Chinese Journal of Geophysics
基金
国家重点自然科学基金项目 (4 0 2 3 3 0 2 8)资助
关键词
华北降水
年代际变化
年际变化
奇异值分解(SVD)
Rainfall in North China, Interdecadal variation, Interannual variation, Singular value decomposition (SVD)
