A simple baroclinic semi geostrophic model on an equatorial β plane is employed the effects of the vertical shear of the basic zonal geostrophic flow and the variation of the basic potential temperature on the long equatorial Rossby waves . A dimensionless parameter σis introduced to represent the variation of basic potintial temperature field ,in the thermodynamics equation.

Firstly,three main development stages in numerical weather forecast and climate simulation research in our Institute,namely the geostrophic model development stage from 1964 to 1972,four primitive equation model one from 1973 to 1986,and model operation uses and wide application of numerical simulation from 1987 to now,has been classified since the middle 1960's.

Starting from a barotropic model equations including large scale orography,friction and heat factor,by means of scale analysis and small parameter method,then a barotropic quasi geostrophic model with large scale orography,friction and heating is obtained.

Starting from a modified barotropic quasi geostrophic model equation, considering the actual situation of the large orography of the Qinghai Xizang Plateau, neglecting its east west slope, the solitary waves are obtained using reductive perturbation method. The results show that the orography is an essential factor to excite Rossby solitary waves in basic flow without shear.

A two layer quasi geostrophic model forced by surface friction and radiative relaxation is used to study numerically the phenomenon of subcritical instability in baroclinic atmosphere.

A detailed test of a simple nonlinear quasi-geostrophic model of stratospheric sudden warming has been performed.

We describe a series of sensitivity experiments with a quasi-geostrophic model of the interaction of stationary planetary waves with the mean zonal flow in the stratosphere and mesosphere.

Sensitivity experiments with a quasi-geostrophic model of stratospheric sudden warming

Barotropic-Baroclinic instability of horizontally and vertically shearing mean monsoon flow during July is investigated numerically by using a 10-layer quasi-geostrophic model.

A quasi-geostrophic model is applied to deduce the effect of the topographic complex on the Indian peninsula.

In the long-period numerical forcast models, many factors, such as non-adiabatic heating and friction, must be considered. The object of this paper is to study the stability of long wave under the influence of these factors. A two-level quasi-geostrophic model including the effect of non-adiabatic heating, friction and horizontal austausch (1)-(3) is used. The instability criterion is given as (10). In the case of baroclinic atmosphere without these factors the criterion agrees with that of Phillips'(fig....

In the long-period numerical forcast models, many factors, such as non-adiabatic heating and friction, must be considered. The object of this paper is to study the stability of long wave under the influence of these factors. A two-level quasi-geostrophic model including the effect of non-adiabatic heating, friction and horizontal austausch (1)-(3) is used. The instability criterion is given as (10). In the case of baroclinic atmosphere without these factors the criterion agrees with that of Phillips'(fig. 1). It is found that in barotropic atmosphere the friction and horizontal austausch are purely damping factors. In baroclinic atmosphere it is, however, not so simple. With the parameter A_T=A_v=0.00213 arc~2 day~(-1),k=0.26 day~(-1),ε=1.05 arc~(-2) day~(-1), A_1~2=30.4 arc~(-2), the curves of stability criterion are given in fig. 2. We notice in the figure that for sufficiently short wave or for small wind shear, these parameters are damping factors; but for long waves (m, n<3) the minimum baroclinity for initia'e instability is smaller than that for the case without these factors. Finally, the structure of the unstable wave.is shown in fig. 4a-b. Fig. 4a is without damping factors and the other is with these factors under the same baroclinity. It may be seen that these factors decrease the instability. In the case without damping factors the disturbance starts to damp when the temperature wave and pressure wave are in phase, but in the case with damping factors the disturbance starts to damp when the phase of temperature wave is still left behind the pressure wave (fig. 4c). This is because when the phase of temperature wave is left behind the pressure wave, there is release of potential energy and this energy is used to compensate the frictional loss.

Using a two-layer quasi-geostrophic model with the potential height φ at any specific time expressed as Fourier series, the nonlinear ordinary differential equations are obtained. The evolution of medium-range weather process is investigated. Some effects of the sea-land contrast and the nonlinear interaction between different wave components are considered.It is shown that the zonal circulation is transformed into meridional circulation and the polar anticyclones are created. The transformation of the...

Using a two-layer quasi-geostrophic model with the potential height φ at any specific time expressed as Fourier series, the nonlinear ordinary differential equations are obtained. The evolution of medium-range weather process is investigated. Some effects of the sea-land contrast and the nonlinear interaction between different wave components are considered.It is shown that the zonal circulation is transformed into meridional circulation and the polar anticyclones are created. The transformation of the large-scale circulation is mainly due to the development of ultra-long waves. Some effects of dynamical and thermodynamical factors are also discussed.

The response of the Northern Hemispheric multi-level model atmosphere to forcing by stationary heat sources in winter is investigated by means of a steady and quasi-geostrophic model in a spherical coordinate system.The results computed from this model show that the amplitude of stationary planetary waves responding to forcing is larger by stationary heat sources at high latitudes than by those at middle latitudes. The results also show that the larger the meridional width of stationary heat sources,...

The response of the Northern Hemispheric multi-level model atmosphere to forcing by stationary heat sources in winter is investigated by means of a steady and quasi-geostrophic model in a spherical coordinate system.The results computed from this model show that the amplitude of stationary planetary waves responding to forcing is larger by stationary heat sources at high latitudes than by those at middle latitudes. The results also show that the larger the meridional width of stationary heat sources, the larger the amplitude of stationary planetary waves responding to forcing is.