DIAGNOSTIC ANALYSIS ON THE DYNAMICS AND NUMERICAL SIMULATION OF CLEAR AIR TURBULENCE(CAT)

Clear air turbulence(CAT).a meso-or microscale(subgrid scale) phenomenon occurring insynoptic scale flow field at high altitude,is very difficult to be observed by the conventional observation network.Thus it is necessary to approach an index to predict CAT.But at first,the structure characteristics of CAT should be preanalyzed.In this paper,based on the theoretical and diag-nostic analysis of a case,features for wind profile,energy budget and dynamic mechanism of thiscase were presented.Furthermore,an objective and quantitative index for CAT forecast was given.The verification for its efficiency was done with both realtime observation data and productsfrom a numerical model.The results are very encouraging.