影响柴达木盆地降水量变化的主要天气动力因素

为了解柴达木盆地内近57 a来降水量变化与太阳黑子、北极涛动(AO)和厄尔尼诺-南方涛动(ENSO)等因素间的关系,运用线性趋势法、Mann-Kendall检验法和小波分析法等对盆地内8个气象站的降水量进行了分析。发现近57 a来盆地内降水量年平均增加0.628 mm,夏季增加0.423 mm,夏季降水占全年总增加量的67%,年降水量存在2~3 a和1 a的显著周期。降水量与太阳黑子相对数存在近似正相关的8~12 a的主共振周期,降水量滞后1.2~1.8 a。年降水量与AO主要存在近似正相关的2~3 a和1~2 a的共振周期。年降水量与ENSO存在近似负相关的3 a和近似正相关的5~6 a的共振周期。表明盆地内降水与其天气动力因素在不同的周期尺度上存在不同的相关性。

The main weather dynamic factors affecting precipitation change in the Qaidam Basin

To study the trends in precipitation and their relations with sunspots,the Arctic Oscillation (AO),and the El Nio-Southern Oscillation (ENSO) in the Qaidam Basin in the previous 57 years,the linear trend method,anomaly analysis,Mann-Kendall test,and wavelet analysis method were used.The precipitation data were obtained from 8 meteorological stations located in the basin.The results showed that the mean annual precipitation in the basin increased by 0.628 mm and by 0.423 mm in the summer during the previous 57 years.The summer precipitation accounted for 67% of the total annual increase,and the mean annual precipitation exhibited significant variation periods of 2-3 years and 1 year.A significant approximately in-phase resonance oscillation of 8-12 years could be observed between the annual precipitation and the sunspot number,with the precipitation lagging by 1.2-1.8 years.The mean annual precipitation and AO existed in approximately in-phase resonance oscillations of 2-3 years and 1-2 years.The mean annual precipitation was inversely related to the ENSO during a 3 year resonant period and was almost positively related to the ENSO in a 5-6 year resonant period.The results indicated that there were different correlations between precipitation and the dynamic weather factors at different periodic scales.