荒漠区粗糙度长度的确定及在模式中的应用

利用2005年进行的“绿洲系统能量与水分循环补充观测试验”第3阶段的观测资料计算了金塔试验区内戈壁和沙漠的动力学和热力学粗糙度长度，沙漠和戈壁的动力粗糙度长度分别为1.81×10-3m和1.64×10-3 m，与黑河试验结果基本一致，均为沙漠的动力粗糙度大于戈壁。试验区内沙漠和戈壁的热力粗糙度长度分别是0.28×10-3 m和0.62×10-3 m。将计算得到的粗糙度长度代入Noah陆面模式，模拟的戈壁、沙漠上的地表温度和感热通量同观测值较为一致，优于原粗糙度长度的模拟结果，大大提高了该模式在沙漠、戈壁特殊区域的模拟能力，有利于将耦合了Noah模式的中尺度模式更好地应用到绿洲系统的研究中。

Calculation of Roughness Length of Desert and Its Application in Land Surface Process Model

Using the data from the third phase of "The Oasis System Energy and Water Cycle Field Experiment" in 2005, we calculated the aerodynamic and thermal roughness lengths of desert surface in Jinta Oasis area. The aerodynamic roughness lengths of sandy desert and gobi in Jinta Oasis area were 1.81×10-3 m and 1.64×10-3 m respectively, and they were similar to the calculation results from the HEIFE experiment in Heihe River basin: the aerodynamic roughness length of sandy desert was bigger than that of Gobi. The thermal roughness lengths of sandy desert and gobi in Jinta Oasis area were 0.28×10-3m and 0.62×10-3 m, respectively. When the roughness length data were replaced into the Noah land surface process model coupled in MM5 and WRF models, the simulation results of surface temperature and sensible heat flux in sandy desert and gobi were quite consistent with the observation results. The simulation capability of surface temperature and sensible heat flux in desert area could be improved a lot using the aerodynamic and thermal roughness length data. This would be favorable to the application of the Noah model to the oasis system study.