Radar observations of prevailing winds and waves in the Southern Hemisphere mesosphere and lower thermosphere

HF radar stations (utilizing the spaced-antenna partial-reflection technique) located at Adelaide (35°S, 138°E) and Mawson Station (67°S, 63°E) have observed horizontal mesospheric winds continuously since mid-1984. Observations in the period 1984–87 are compared with the Northern Hemisphere [latitude conjugate] stations of Kyoto (35°N, 136°E) and Poker Flat (65°N, 147°W), and with satellite-derived circulation models. Particular reference is made to the equinoctial changeovers in zonal flow and to the temporal and altitude variations in the planetary wave activity at Mawson and Adelaide.     

Body force circulations in a compressible atmosphere: Key concepts

The body force circulation problem of Eliassen is extended to spherical geometry and a quasi-compressible atmosphere using the zonally symmetric tidal theory. The concept of body force circulation is generalized to include the effects of mechanical friction and Newtonian cooling. This viewpoint is conceptually advantageous when the circulation is driven by body forces against radiative relaxation. The resulting linear theory is qualitatively useful in middle atmosphere applications, including the equatorial momentum source for which an analytic solution has not been given previously. Further generalizations of the theory are possible by including dynamical and photochemical feedback effects.     

江淮流域汛期降水时空分布特征及其环流背景初步分析

应用对应分析等方法分析了江淮流域汛期(5月～9月)降水的时空分布特征,在此基础上按降水旬际变化特征将论域初划为4个区域,最后讨论了各降水区降水异常的500hPa低阶流场背景.     

多层递推平稳模型

通过对小概率事件历史样本作多层递推迭代，逐次改变引入样本数求取权函数，建立一种平稳统计模式。模式信息容量大，收敛快，克服了常规统计模式的局限性，在灾害性天气客观预报模型应用中取得了明显效果。     

Numerical Modelling of the Effects of Ozone on the Summer Atmospheric Circulation

ＮｕｍｅｒｉｃａｌＭｏｄｅｌｌｉｎｇｏｆｔｈｅＥｆｆｅｃｔｓｏｆＯｚｏｎｅｏｎｔｈｅＳｕｍｍｅｒＡｔｍｏｓｐｈｅｒｉｃＣｉｒｃｕｌａｔｉｏｎＷａｎｇＱｉａｎｑｉａｎ（王谦谦）；ＷａｎｇＹｉｎｈｕｉ（汪迎辉）；ＳｏｎｇＹｕ（宋煜）（Ｎａｍｉｎｇｉｎｓｔ...     

MODULATION OF ATMOSPHERIC THERMAL AND MECHANICAL FORCINGS AND NUMERICAL MODELING OF MEAN MERIDIONAL CIRCULATION

Upon investigating the relative locations of internal and external forcing and the resultant mean meridional circulation,it was found that thermal forcing and mechanical forcing for the formation of atmospheric mean meridional circulation are modulated by a certain ratio.This ratio is determined by the inherent baroclinity,static stability and absolute vorticity of the atmosphere.By employing a parameterization scheme for radiative heating and condensation heating,together with the analysisdata of the European Center for Medium-range Weather Forecasts,the mean meridional circulation for January wassimulated numerically.It was found that latent heat release in the tropics may result in the formation of double-layeredHadley circulation,so do the eddy momentum transfer processes.On the other hand,mean meridional circulations in extra-tropics are mainly determined by external momentum forcing and atmospheric properties of eddy momentum andheat transfer.     

旋转流体物理实验中见到的大气环流特征

在合适的实验参数下(热力Rossby数R_(OT)=0.1,Taylor数T_a=2.2 ×10~7),在旋转斜压流中,大尺度地形强迫造成低频振荡以及大气环流中的“阻塞”流型。这是由于地形强迫造成的准静止波与行进波的相互作用及共振引起的。地形把波数单一的流动变成多波数的流动。地形强迫使波数减少。     

海温作用与低频振荡

提出一个求定常方程平衡数值解的方法,并利用这个方法求得了雷州半岛海风环流的稳定数值解,在一定下边界强迫下得到了和观侧相一致的环流状态,进而讨论了大气参数对海风环流的影响,试验表明,所提出的求解方法是有效的.