PHYSICAL MODELLING EXPERIMENTS OF TOPOGRAPHICAL AND THERMAL EFFECTS ON ATMOSPHERIC CIRCULATION IN VICINITY OF ANTARCTICA

Numerous physical fluid experiments have been performed to study effect sof Antarctic to pography andits surface cooling on the atmospheric circulation in vincinity of Antarctica. The primary dynamical similarity parameters in the experiments are thermal Rossby number ROT and Taylor number Ta. The experiments show that in condition with experimental parameters close to the at mosphere, a divergent drainage at low level and a polar vortexat middle-high levels form in the fluid. The polar vortex includes three-four troughs travelling east ward around polar circle, and form a wavelike structure of planetary circulation around Antarctica periphery. It is found that there is a low frequency oscillation in shape and amplitude of travelling waves. The period of this oscillation is equivalent to 21 days in the earth's at mosphere system. The east ward travelling troughs gradually develop from longitude of 110°E, and become most developed at longitude of 160°Wnear Ross Sea, and then gradually weaken futhereast. The experiments show that the effects of Antar cticatopography and its surface cooling are very important in formation of At mospheric circulation feature in vicinity of Antarctica.