Observational Study on Air-flow around the Tibetan Plateau

Abstract

The observational study by using station data has been conducted to investigate the edge disturbances around the Tibetan Plateau which are found in numerical simulations. Two types of effects of the mountain are found; one is the effect on synoptic disturbances, which corresponds to the main cold surge events, and the other is the excitation of the edge disturbances whose horizontal scale is consistent with the radius of deformation. This corresponds to the disturbance simulated in the numerical model. It is also found that the edge disturbance is not always excited. A relationship between the intensity of a trough ahead of the Tibetan Plateau and the excitation of edge disturbances is suggested by this study. The existence of two different types of influence by the Tibetan Plateau is consistent with the different paths of cold air outbreak over Mainland China.