WRF中三种边界层参数化方案对新疆2.28大风过程模拟的对比分析

许多研究调查了模式预报对边界层方案的敏感性，但是这些研究基本上针对的是热力驱动的混合边界层。对于动力驱动的边界层，不同边界层方案的不同性能以及所带来的不同边界层气象要素的预报还不清楚。运用WRF3.4.1中三种边界参数化方案（YSU、MYJ、ACM2）对新疆2.28大风过程进行数值模拟分析，结果显示：三种边界参数化方案基本能模拟出发生大风的区域及大风过程中10m风速、2m温度和比湿的变化趋势；三种方案模拟的边界层内大气的温度、湿度出现差异与它们对边界层顶的夹卷过程、边界层内垂直混合的处理有关；YSU方案的模拟结果使得更多的高空动量下传，同时更多的有效位能转化为动能，MYJ方案模拟的20m/s的风场区域更大，受地形影响更明显，边界层内湍流更强。

Evaluation of Three Planetary Boundary Layer Schemes in the WRF Model for the 28 February 2007 Gust Episode in Xinjiang

Although many studies have investigated the sensitivity of mesoscale models forecast with different the PBL(Planet Boundary Layer) parameterization schemes, they mostly focus on mixed PBL driven by heat. The features and performance of different PBL parameterization schemes for the mechanically driven boundary layer have not been clear yet. Numerical simulations were conducted with the Weather Research and Forecasting (version3.4.1) model to analyze a gust process occurred in Xinjiang Province on February 28th based on three different PBL schemes. It shows that these three different PBL schemes can reasonably simulate the domain of the gust and the trend of wind speed at 10m above ground level. Differences in vertical mixing strength and entrainment of air above the PBL are the main reasons why there are differences on analog result of temperature and specific humidity in PBL among the three schemes. Though the result of YSU scheme indicates more downward momentum flux from upper air and more effective potential energy transformed into kinetic energy, wind field where air speed reaches 20 m/s simulated by MYJ is larger and the turbulence in PBL is stronger when compared with YSU and ACM2.