Some aspects of the energy balance closure problem

[摘要] After briefly discussing several reasons for the energy balance closureproblem in the surface layer, the paper focuses on the influence of the lowfrequency part of the turbulence spectrum on the residual. Changes in theturbulent fluxes in this part of the turbulence spectrum were found to havea significant influence on the changes of the residual. Using the ogivemethod, it was found that the eddy-covariance method underestimatesturbulent fluxes in the case of ogives converging for measuring times longerthan the typical averaging interval of 30 min. Additionally, theeddy-covariance method underestimates turbulent fluxes for maximal ogivefunctions within the averaging interval, both mainly due to advection andnon-steady state conditions. This has a considerable influence on the use ofthe eddy-covariance method.

[学科分类] 大气科学