高空大尺度涡度湍流输送的一些统计性质

应用1956年二月份的高空材料,作者研究了两层模式中各项湍流性涡动输送项的统计性质.根据北京、伊尔库次克、莫斯科、巴黎、奥斯陆等五个地点各不同时间问题中涡度湍流输送的大小和变化分析,可以初步确定:一般说来湍流项并不一定此平均输送项来得个多少,因此不一定可以略去.并且湍流项与平均项之间并没有线性关系等简单关系,因此对于简单地表示出来.由此看来,利用平均运动方程来作中、长期数值预报是不大方便的.

A STATISTICAL STUDY OF EDDY TRANSFER OF VORTICITY IN THE LARGE-SCALE TIME-AVERAGED MOTION

Using the upper air data for February 1956 some statistical behavior of the various eddy transfer term in the time-averaged vorticity equation for a two-layer model is studied. According to the analysis for five stations (Peking, Irkutsk, Moscow, Paris, Oslo) for various time intervals, up to one month, it is found that the eddy transfer term is not necessarily smaller than the mean transfer term, and thus not negligible. It is also pointed out that there exists no simple relation between these two terms. In this respect, the time-averaged equation of vorticity without eddy term is not convenient for the work of nume-rical forecasting.