A Dynamic Study of Ekman Characteristics by Using 1998 SCSMEX and TIPEX Boundary Layer Data

A dynamic study on Ekman characteristics by using 1998 SCSMEX and TIPEX boundary layerdata is made. The results are as follows: (1) Similar dynamical Ekman characteristics are observed in theTibetan Plateau and in the South China Sea and its surrounding area. (2) The thickness of the boundarylayer is about 2250 m over the Tibetan Plateau, and considering its variation, the thickness could be up to2250-2750 m. In the tropical southwest Pacific, the thickness of the boundary layer is about 2000 m, andthe variation is smaller; a smaller thickness of the boundary layer is in the plain area of the Bohai Sea.(3) Because of the difference in elevation between the Tibetan Plateau and the tropical ocean area, theinfluence of the boundary layer on the atmosphere is quite different although the two areas have almostthe same thickness for the boundary layer, the height where the friction forcing occurs is quite different.(4) The vertical structure of turbulence friction is quite different in the Plateau and in the tropical oceanarea. Calculations by 1998 SCSMEX and TIPEX boundary layer data indicate that even in the lowestlevels, eddy viscosity in the Tibetan Plateauan can be 2.3 times than in the tropical ocean area.