1951-2018年河北围场地区降水的多尺度变化特征

Multi-scale features of precipitation in the Weichang region Hebei Province from 1951 to 2018

利用1951-2018年河北围场地区气象站年降水量和同期的厄尔尼诺(ENSO)、太平洋年代际振荡(PDO)数据,采用集合经验模态分解(EEMD)和Morlet小波分析等方法,研究了河北围场地区1951-2018年降水量的多尺度变化特征及其与厄尔尼诺和太平洋年代际振荡的关系。结果表明:1951-2018年围场地区年降水量总体上表现为增加的变化趋势,增幅为0.8 mm/10a;围场地区年降水量在时间尺度上存在显著的准4 a和准27 a的年际和年代际周期,分别与厄尔尼诺的2~7 a和太平洋年代际振荡的20~30 a周期相对应;交叉小波谱和小波凝聚谱表明,围场地区的年降水量与ENSO和PDO之间具有较好的共振周期,说明1951-2018年围场地区的年降水量可能受到厄尔尼诺和太平洋年代际振荡的影响。

Data on the annual precipitation and its corresponding El Nino-Southern Oscillation(ENSO)and Pacific Decadal Oscillation(PDO)data at the meteorological station in the Weichang region of Hebei Province from 1951 to 2018 were collected.Multi-scale features of the annual precipitation in the Weichang region from 1951 to 2018 and its relationship with ENSO and the PDO were analyzed using ensemble empirical mode decomposition(EEDM)and Morlet wavelet analysis.The results showed that the annual precipitation in the Weichang region from 1951 to 2018 showed a general increasing trend with an increase of 0.8 mm/10 a.There existed obvious interannual and interdecadal changes of 4 a and 27 a,which had a good correspondence with the 2-7 a cycle of ENSO and the 20-30 a cycle of PDO respectively.The cross wavelet and wavelet cross coagulation spectrum showed that the annual precipitation in the Weichang region had a good resonance period with ENSO and PDO,indicating that the annual precipitation in this region could be affected by ENSO and PDO.