The Clouds with the Shape of Karman Vortex Street in the Wake of Cheju Island, Korea

[摘要] The properties of the clouds with the shape of Kármán vortex street in the wake of Cheju Island, Korea are studied using satellite pictures which are taken approximately four hours apart. The results indicate that non-dimensional numbers and physical quantities obtained from the cloud vortex street satisfy theoretically as well as experimentally obtained criteria of Karman vortex street. The equation of the displacement of the cloud vortex street is derived through drag consideration. The displacement speed obtained from this equation agrees fairly well with the observed value. The speed is approximately 76% of the undisturbed flow when the ratio between the spacing of two rows and that of individual vortex is 0.332.It is foundd that such a cloud vortex street appears in the wake of Cheju Island from late autumn to early spring when steady northerly wind of more than moderate intensity (above 10 kts) prevails and a well defined inversion is found at around 1000 meters or at about half the height of the mountain located in the center of the Island.

[学科分类] 大气科学