The Comparison of Six Methods to Calculate Turbulent Momentum Transfer Coefficient of Near-surface Layer

The momentum bulk transfer coefficient (C_M) is calculated by using six typical parameterization schemes and verified by the data of Naqu flux observation station of GAME (Global Energy and Water Cycle Experiment, Asian Monsoon Experiment)/Tibet Plateau Experiment. The results show obvious difference exists between results of the six schemes and the degree of difference is decided by the type of undersurface and the near surface stability. Wherein, schemes of Businger 71, Dyer 74 and B & H91 must calculate the turbulent flux transfer coefficient by iteration and waste CPU time for numerical simulation. For flux data of Naqu observation station which is covered by sparse grass is considered, when the Richardson number is less than 0.1, all the other five schemes can do better estimation on the C_M except the scheme of Businger in 1971 which has an obvious underestimation. Under unstable conditions, the scheme of Dyer in 1974 has the best estimation on the momentum bulk transfer coefficient (C_M), the schemes of Wang et al. in 2002, Launiainen in 1995 and Louis et al. in 1982 can also be used with gradually increasing error, and the scheme of Businger in 1971 has serious underestimation.