中高纬大气季节内振荡特征的诊断研究  

DIAGNOSTIC STUDY FOR INTRASEASONAL OSCILLATIONS OF THE MIDDLE-HIGH LATITUDES IN THE OBSERVATIONAL ATMOSPHERE

作　　者：王召民[1] 倪允琪[1] 张勤 

机构地区：[1]南京大学大气科学及 [2]南京气象学院

出　　处：《气象科学》1992年第3期266-276,共11页Journal of the Meteorological Sciences

摘　　要：本文采用ECMRWF1980—1988年u,v,z格点资料,进行Munakami带通滤波,分析中高纬大气季节内振荡的动力学特征及传播特征,以及与热带地区季节内振荡的差异。 在全球高度场单点相关图上,南北半球都有类似于波列的分布结构,它们有相同的视源区与视汇区,季节内振荡具有全球尺度特征。超前或滞后相关图上,可以发现季节内振荡具有40—50天振荡周期。 在高度场四个位相合成图上,我们发现中高纬高度场上反映的季节内振荡为定常波的振荡,即波列位相与振幅的振荡。 低纬地区速度势函数冬季为纬向一波结构,夏季为二波结构。合成的赤道区域时剖图上,冬季X场东传明显,夏季则仅东半球有东传现象。OLR场冬季主要为150E为节点的东西向偶极形式的振荡以及60W—O范围的局地振荡。 热带区域季节内振荡主要表现为行星波的传播,而中高纬大气的季节内振荡表现为定常波的振荡。In this paper, we used nine years (1980-1988) observational grid data of ECMRWF. The U. V. Z data are band-passed with Murakami methods in order to analyse the dynamic and propagation characters of intraseasonal oscillations of the middle-high latitudes and the differences between the characters of the intraseasonal oscillations over the tropical area and over the middle-high latitudes. In the one-point correlation charts of the global height fields, we find that there exist the distributien ef the wavelike structures in the southern and northern hemisphere. They seem to have the same tropical heat sources. The intraseasonal oscillations are of the global scale. In the lag correlation charts, we also find that intraseasonal oscillation are of the 40-50 days period. In the four composite maps of height fields, the intraseasonal oscillations of the middle-high latitudes exhibit phase and amplitude oscillation of the standing planetary waves. The tropical velocity potential wave is of the zonal structure of wevenumber 1 and has the significant eastward propagation character in winter. But in summer it is of the zonal structure of wavenumber 2 and only between 0-180E does it have the eastward propagation character. The tropical OLR exhibits east-west dipole-form oscillation between the equatorial ndian Ocean and the western Pacific and local oscillation between 60W-0. The intraseasonal oscillations of the middle-high latitudes exhibit the oscillations of the standing planetary wavp. but in the tropics, they exhibit the propagation of the planetary wave.

关 键 词：高纬 高度场 合成图 相关图 诊断研究 定常波 势函数 带通滤波 振荡周期 格点资料 

分 类 号：P4[天文地球—大气科学及气象学]