This paper discusses the important role that flux profile relations play in momentum flux, sensible heat flux, and latent heat flux simulations in CoLM （Common Land Model） and compares the application of three flux profile relation schemes in CoLM by means of the Loess Plateau Land-Atmosphere Interaction Pilot Experiment （LOPEX） of 2005. It reveals that the results simulated by the model barely changed in the original flux profile schemes of the models a^er eliminating the very stable condition and the very unstable condition, and there were only tiny changes in numerical values. This indicates that the corrected terms added to fm（ξm）,fh（ξh） were very tiny and can be ignored under very stable and very unstable circumstances. According to a comparison of the three flux profile relations, the simulation results were basically coherent by using any CoLM： the correlation coefficient of the simulation value and the observed value was 0.89, and this bears on the coherence with the numerical procedures for the flux pro- file relations under unstable circumstances. The simulation results were improved considerably by utilizing the Lobocki flux pro- file schemes, which numerical procedures under unstable circumstances differed significantly fi＇om other three flux profile schemes; in this case the correlation coefficient of the value of simulation and the observed value became 0.95. In the next itera- tion of this study, it will be of great importance for the development of the land surface process model to continue experimenting with the application of some novel flux profile schemes in the land surface process models in typical regions.
ZhenChao LiZhiGang WeiaZhiYuan ZhengHong WeiHui Liu
Land surface processes take place on the interface between the earth and atmosphere, exerting significant influ- ences on the weather and climate. Correct modeling of these processes is important to numerical weather forecast and climate prediction. In order to obtain a more thorough understanding of the land surface processes over the Gobi landscape, we evaluated the performance of the Common Land Model （CoLM） at Dunhuang station in Gansu Province of China to determine whether the model formulation, driven by observational data, is capable of simulat- ing surface fluxes over the underlying desert surface. In comparison with the enhanced observation data collected at Dunhuang station over the period 22-28 August 2008, the results showed that the surface albedo simulated by CoLM was larger than that in the observation, and the simulated surface temperature was lower than the observed. After the measured values were used to correct the surface albedo, the solar radiation absorbed by the ground surface was more consistent with the measurements. A new empirical relationship of the surface thermal exchange coefficient r~ was used to modify the thermal aerodynamic impedance. The simulated soil surface temperature became significantly closer to the observed value, and the simulated surface sensible heat as well as net radiative fluxes were also im- proved,
