THE INFLUENCE OF EDDY VISCOSITY ON THE SUBTROPICAL PLANETARY-SCALE CIRCULATION IN SUMMER

The influence of eddy viscosity on the distribution of subtropical quasi-stationary planetary waves in summer is analysed theoretically.It is found that since the basic flow is very weak,the eddy viscosity may play an important role for the subtropical planetary-scale motion in summer.A linear,quasi-geostrophic,34-level spherical coordinate model is also utilized to calculate the differences of quasi-stationary planetary waves and of quasi-stationary disturbance pattern responding to forcing by topography and heat sources under the different eddy viscosities.The computed results show that the coefficient of eddy viscosity considerably influences the strength of the subtropical planetary-scale circulation in summer.