ANNUAL CYCLE AND SEASONAL VARIABILITY OF ZONAL WIND VELOCITY CIRCULATION FROM OBSERVATIONS AND SIMULATION RESULTS

E. V. Sokolikhina, E. K. Semenov, D. Yu. Gushchina, and L. Terray

By using an integral circulation index, the zonal wind velocity circulation round the latitude circle, features of the annual cycle and seasonal variability of the atmospheric zonal circulation are studied, and the accuracy of atmospheric circulation simulation by the ARPEGE general circulation model is estimated. Attention is paid to simulation of the annual cycle and seasonal variability of the zonal velocity circulation. Also, results of the numerical model experiments are analyzed with different initial conditions and underlying surface (ocean) forcing, which allows estimating the model sensitivity to initial and boundary conditions and contribution of the internal and external variability of the atmosphere to the global circulation distribution.