ABSTRACT

This chapter addresses the computation of the different energy fluxes exchanged at the earth-atmosphere interface, namely the fluxes of momentum, sensible and latent heat. These fluxes result from the partitioning of the net solar radiation absorbed at the ground. In many planetary boundary layer problems the physics is too complex and is insufficiently known to formulate principles for the governing equations. Planetary boundary layer observations constitute, therefore, the only basis for any formulation used in the estimation of the surface fluxes. The chapter provides the Program (SIMFLX), which gives a complete illustration on the use of the similarity theory in surface fluxes calculations. The vertical distribution of the surface fluxes within the lowest tropospheric levels requires an estimation of the height of the planetary boundary layer. Generally the fluxes are set to zero at the top boundary and equated to the surface fluxes at the lower boundary.