南极地区的大气环流流体物理实验

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

通过流体物理实验，研究南极地形及冷源对大气环流的影响。正压流体实验表明，由于地形动力强迫，在南极大陆沿岸及以北地区生成气旋性涡旋带，有３个低压中心。在地形上空生成巨大的反气旋。斜压流体实验表明，东移“行星波”的波数及波形有准周期低频振荡，其振荡周期相当于地球大气系统中的２１ｄ。东移的槽在１１０°Ｅ以东逐渐发展，在１６０°Ｗ的罗斯海附近发展得最深。

Numerous physical fluid experiments have been performed to study effects of Antarctic topography and its surface cooling on the atmospheric circulation in vincinity of Antarctica.The primary dynamical similarity parameters in the experiments are thermal Rossby number R OT and Taylor number T a .The experiments show that in condition with experimental parameters close to the atmosphere,a divergent drainage at low level and a polar vortex at middle high levels form in the fluid. The polar vortex includes three four troughs travelling eastward 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 atmosphere system.The eastward travelling troughs gradually develop from longitude of 110°E,and become most developed at longitude of 160°W near Ross Sea,and then gradually weaken futher east.The experiments show that the effects of Antarctica topography and its surface cooling are very important in formation of Atmospheric circulation feature in vicinity of Antarctica.