不同行星边界层参数化方案对新疆降水模拟的影响研究

使用NCEP-FNL全球分析资料作为WRF模式的初始场和边界场，利用该模式中6种行星边界层参数化方案对新疆进行2006年10月1日至2008年1月1日的模拟积分试验，重点考察模式在10 km水平分辨率下不同行星边界层参数化方案对新疆降水模拟的敏感性。结果表明:1）采用6种行星边界层参数化方案的模式都能较好地模拟出年、雨季总降水量的空间分布及月降水的季节循环。2）对于新疆整体来说，采用Grenier-Bretherton-McCaa（GBM）方案模拟雨季降水更接近观测，偏差在±30%以内。对于天山地区来说，采用Bougeault-Lacarrere（BouLac）方案模拟年降水更接近观测，偏差为－19.13%；采用GBM方案模拟中雨和大雨的TS评分最高分别为0.37和0.33，并且能够较好地模拟7月5次较大降水日中不同下垫面类型的昼夜降水，偏差在5 mm以内。3）BouLac方案能够较好地模拟天山地区年降水的时空分布特征，GBM方案更适合模拟新疆整体雨季期间降水。因此利用WRF模式开展新疆降水模拟研究时应考虑不同行星边界层参数化方案的适用范围。

Impact of Different Planetary Boundary Layer Parameterization Schemes in the Regional Climate Model on Precipitation Simulation for Xinjiang

NCEP-FNL datasets are used as the initial and boundary fields of the WRF model. Six planetary boundary layer parameterization schemes (PBLPS) are applied in the model for Xinjiang region with 10-km horizontal resolution. The spatial distribution and temporal evolution of the meteorological elements are analyzed. The analysis results show the following aspects: 1) The WRF model with six PBLPS can simulate the seasonal circulation of monthly precipitation and the spatial pattern of annual and rainy season precipitation. 2) For the Xinjiang region, the deviation of rainy season precipitation between the simulation conducted with the Grenier-Bretherton-McCaa (GBM) scheme and the observations is within ±30%. For the Tianshan area, the deviation of annual precipitation between the simulation conducted with the Bougeault-Lacarrere (BouLac) scheme and the observations is －19.13%. The TS scores of moderate and heavy rains are 0.37 and 0.33, respectively, in the test results of daily precipitation simulated with the GBM scheme. For the different types of underlying surfaces in the Tianshan area, the day and night precipitation can be well simulated by the model with the GBM scheme with the deviation of precipitation within 5 mm during long precipitation days. 3) The WRF model with the BouLac scheme can simulate the annual spatial and temporal distribution characteristics of annual precipitation in the Tianshan area, and the rainy seasonal precipitation can be well simulated by the model with the GBM scheme in Xinjiang. Therefore, PLBS with the WRF model in the Xinjiang region should be considered.