江苏地区沙尘天气时空特征及气候变化分析

Analysis on the cliVmate change characteristics of sand/dust days as well as its temporal and spatial features over Jiangsu region

利用江苏省59个测站1960—2006年的沙尘天气观测资料,通过时间序列线性变化趋势、小波分析等方法,研究了江苏沙尘天气的时空分布及年际和年代际变化特征。结果表明:江苏沙尘天气在空间上呈北多南少、西多东少,年发生频数差异明显的特征;47a江苏年沙尘日数年际变化明显,总频次呈减少趋势,沙尘强度呈减弱趋势;江苏沙尘天气季节分布不均匀,3—4月份为多沙尘月,6—10月基本没有沙尘天气发生,11月后沙尘天气开始增多;从小波分析的结果看,江苏沙尘天气具有2、4、6、8a的年际周期变化和11、20a左右的年代际周期振荡,其中8a和20a周期振荡是主要特征,20a的周期振荡贯穿始终。

Based on the available observation data from 59 standard meteorological stations in Jiangsu province from 1960 to 2006, the distribution of temporal and spatial features, and the climate change charateristics of the sand/dust days in Jiangsu region have been analyzed using linear trend method and Morlet wavelet transformation. The results show that the frequency of dust is intensely decreased from north to south, and from west to east. The annual dust days have apparently changed, the frequency is in a decrease trend, and the intensity is in a weaken trend. The seasonal distribution of dust is nonuniform, dust mainly occurs in March and April, it rarely occurs from June to Oct, and begins to increase from Sept. The result of the Morlet wavelet analysis shows that the short periods of 2, 4, 6, 8 years are obvious. Meanwhile, there are 11,20 years long periods. The 8 years and 20 years period are the main characteristics.