Relationship Between Turbulent Energy in the Near Surface Layer and Atmospheric Boundary Layer Thermodynamic Structure over the Southeastern Side of Tibetan Plateau
Based on the data observed from an intensive GPS sounding experiment and the comprehensive measurements of boundary layer in Dali of Yunnan Province during March, May and July 2008, the heights of CBL (convective boundary layer) and SBL(stable boundary layer) are calculated with approaches of temperature gradient and inversion layer strength and sensible heat flux, latent heat flux, turbulent kinetic energy, shear item and buoyancy item are obtained with eddy correlation method. The apparent heat source Q1, which is calculated from the NCEP reanalysis data, presents the similar diurnal cycles to the turbulent energy components and turbulent flux, reflecting a close connection of the plateau’s heat source variations with the diurnal changes in turbulent transport of hydrothermal process in the underlying surface. The comprehensive analysis on the vertical profiles of variables about turbulence and thermodynamics reveals the significant correlations among sensible heat flux, latent heat flux, apparent heat source and buoyancy item, implying an important contribution of thermodynamic turbulence transport to the Q1 in the near surface layer over the southeastern edges of the Tibetan Plateau. The buoyancy item and turbulent energy play an important role in formation of the near surface Q1, vortex dynamics, thermodynamic mixing structure. The lower layer Q1 and moisture sink are closely associated with the boundary layer height. This comprehensive analysis describs a physical linkage of thermodynamic turbulence transport with atmospheric heat source, vortex dynamical process and thermodynamic mixing layer structure to understand the interaction of turbulence convection and atmospheric thermodynamic process in the active convection region over the southeastern edges of the Tibetan Plateau.