1997年华南汛期降水异常与大气低频振荡的关系  

Relation Between Flood Season Precipitation Anomalies in South China and East Asian Atmospheric Low Frequency Oscillation in 1997

作　　者：信飞[1] 肖子牛[2] 李泽椿[3] 

机构地区：[1]南京信息工程大学,上海区域气候中心210044 [2]云南省气象局 [3]国家气象中心

出　　处：《气象》2007年第12期23-30,共8页Meteorological Monthly

摘　　要：利用国家气象中心提供的逐日降水资料及NCEP逐日再分析资料,分析了1997年华南地区汛期异常降水低频特征与大气低频振荡的关系。研究表明,1997年华南前汛期和后汛期降水表现为不同的振荡特征;前汛期降水主要以10～20天准双周振荡为主,而后汛期降水的低频特征并不明显。进一步对降水和其它要素的低频振荡特征进行分析发现,该年华南地区前汛期降水和风场的低频振荡现象是普遍存在的;低频纬向风的传播变化与降水的时间分布有较好的对应。并且,高、低纬度低频风场同时向华南地区传输,会产生极强的降水。在对大气低频扰动动能的分析中也发现,华南前汛期降水伴随着低频扰动动能在该地区的集中释放。By using the daily precipitation data from CMA and NCEP re-analysis daily data, the relation between flood season precipitation anomalies in South China and East Asian atmospheric low frequency oscillation in 1997 was analyzed. Results show that flood season precipitation in South China reveals different low frequency oscillation in pre-flood season and latter flood season. The pre-flood season precipitation is mainly controlled by the oscillation of 10-20 days, but the re- lation between latter flood season precipitation and low frequency oscillation is not very clear. The further study shows that the pre-flood season precipitation in South China obviously connects withlow frequency oscillation of west wind and the precipitation substantially agrees with the low fre- quency oscillation of wind. Meanwhile, one reason of the heavy rain may be the transfer of wind from high and low latitude to South China during this period. Besides, another reason of the heavy rain may be that the kinetic energy perturbation is released concentrically in South China.

关 键 词：汛期 降水异常 低频振荡 

分 类 号：P433[天文地球—大气科学及气象学]