Discussion on Calculation Methods of Sensible Heat Flux during GAME/Tibet in 1998

Based on previous research on sensible heat flux, we investigate it from different aspects usingGAME/Tibet data measured during 6 June-13 September, 1998. This work consists of the derivationof the surface heat flux equation, analysis on counter-gradient heat transference, comparison betweentwo different methods to compute the sensible heat flux, and investigation on the calculation scheme ofsensible heat flux in the Simple Biosphere model 2 (SiB2) with relevant simulation. By improving twoprevious formulations, an integrated formulation for calculating surface heat flux is given. Secondly, usingthe measured data, the counter-gradient heat flux is clarified, leading to the fact that buoyancy plays animportant role in the sensible heat transfer process. It is concluded that (1) energy imbalance is a commonphenomenon resulting from the use of the traditional closure scheme on the heterogeneous underlyingsurface because the measured ensemble heat fluxes by eddy correlation contain the effect of nonlocal parcelmovements; and (2) nonlocal parcel movement deserves more attention in any future heat flux study.