Improvement of surface flux parametrizations with a turbulence-related length

In surface flux parameterizations, aerodynamic roughness length z(m0), and thermal roughness length z(h0), are used to account for different resistances for momentum transfer and heat transfer. This paper introduces a turbulence-related length h(T) and parameterizes the quantity kA(-1) = In(h(T)/z(h0)) in order to estimate z(h0). Based on data at three sites on the Tibetan Plateau, a general formula for kA(-1) is obtained for the surfaces covered by bare soil or partially covered by very short vegetation. A surface flux parametrization with this formula provides better estimates of heat flux than either profile flux parametrization or Surface flux parametrization with kB(-1) (i.e. In(z(m0)/z(h0))), Therefore, the use of a reasonable length to scale z(h0) can contribute to the improvement of surface flux parametrizations.