北半球冬季中高纬30～60天振荡动能源、汇的特征

SOME CHARACTERISTICS OF KINETIC ENERGY SOURCES/SINKS OF 30～ 60 DAY OSCILLATIONIN WINTER NORTHERN HEMISPHERE EXTRATROPICS

摘要:

利用ECMWF/WMO资料,计算了1985年11月～1986年3月的大气低频动能、低频动能通量散度,详细讨论其冬季平均的水平分布特征,并揭示大气低频动能源和汇的水平传播特征。结果表明:大气低频动能的大值中心正好对应于持续性异常的活动中心,且主要位于大气环流遥相关型PNA和EU波列路径附近,大气低频动能的强源(汇)主要位于西风急流的出口(入口)区;在中高纬地区,大气低频动能源和汇主要呈现向西的纬向传播特征和向北的经向传播特征。

关键词:动能;源和汇、低频振荡

Abstract:

Based on ECMWF/WMO data.the November 1985～March 1986 atmospheric lowfrequeney kinetic energy and its flux divergencea are computed and their horizontal distributionfeatures of the winter averages doeumented in detail,togeth,with the horizontal propagation characteristics of the energy sources/sinks revealed.Results show that the maximum kinetic ener gy centers are related to the persistent anomaly cores of action.usually adjacent to the wavetracks of the teleconnections PNA and EU;the robust low frequency kinctic energy sourees(sinks)are located largely at the exit(entrance)of westerly jet:the sources/sinks move predominantly west-and nort h ward at extratropical latitudes in winter,

Key words:kinctic energy;sourees and sinks;low-frequency oscillation