【摘要】 利用青海省41个测站,1961~2005年6~8月降水量资料,采用REOF、小波分析及突变分析等方法,对青海省夏季降水量的空间异常特征和时间变化规律进行了诊断研究。结果表明:旋转后的前3个载荷向量可较好地代表青海夏季降水的3个主要异常敏感区:青海东部区、西部区和南部区。近45 a来,各区夏季降水趋势分别表现为无显著变化(东部区)、增加(西部区)和减少(南部区)。除具有4 a和10~12 a左右的振荡周期外,各异常区还具有各自不同的振荡周期。青海省夏季降水突变的时间约发生在1970和1999年。更多还原

【Abstract】 With REOF,Morlet wavelet,spectral analysis method,the spatial anomaly features and time evolution rule of summer precipitation anomaly in Qinghai are studied by using the precipitation data in June,July and August for the period 1960～2005 from 41 observation stations.The results show that the first three rotated loading vector fields represent three principal precipitation anomaly areas: East,West,and South of Qinghai.Summer precipitation tendency of every division presents unchangeableness,increasing and decreasing respectively in the last 45 years.Morlet wavelet analysis indicates that there are different oscillation periods besides 4a and 10～12 a periods in every regions.The abrupt change occurred in about 1970 and 1999.更多还原