WRF模式对金塔绿洲效应的数值模拟

Numerical Simulation of Oasis Effect in Jinta Oasis Using the WRF Model

利用美国NCAR中心的天气研究与预报模式WRF,对金塔绿洲的温度场、环流场、能量场的结构及其日变化特征进行了较为细致的模拟研究。结果表明,WRF模式能较好地模拟出非均匀下垫面上绿洲和戈壁的近地面温度、风场、净辐射、感热和潜热等要素的变化特征及日变化规律,较为完整地呈现出绿洲"冷岛效应",模拟的近地面风向和观测值吻合较好。通过对能量场的时空分析,发现下垫面的植被类型、土壤类型和土壤湿度对绿洲白天感热、潜热、土壤热通量和净辐射等有很大影响,绿洲白天净辐射峰值比戈壁大,潜热通量比感热通量大;白天大气向地面传输热量,绿洲地表获得的热通量大;而夜间地表向上传递热量,绿洲释放的热通量比戈壁大。更加细致地研究这些现象对深入了解绿洲气候的形成和维持机理具有重要的意义。

The characteristics of air temperature,circulation and energy budget in Jinta Oasis are simulated using the Weather Research and Forecasting（WRF） model Version 3.1,which developed by the National Center for Atmospheric Research.The results show that the WRF model has good quality in simulating the diurnal characteristics of surface temperature,wind,net radiation,sensible heat and latent heat fluxes.The simulated results reappear the ＇cold island＇ effects of oasis and the surface wind direction agrees well with observed values.Based on analyzing the energy budget,it is found that the soil moisture,soil and vegetation types have significant impact on the sensible heat flux,latent heat flux,ground heat flux and net radiation in the daytime in the oasis.In the daytime,the peak value of net radiation over oasis is larger than that in Gobi,sensible heat flux is larger than latent heat flux.Energy was transmitting from atmosphere to land surface in the day time and reversing at the nighttime,the oasis was obtained more heat fluxes in the daytime and released more at the night-time.Studying these phenomenons has an important significance on oasis climate formation and maintaining.