复杂下垫面近地层湍流通量参数化方案及对风速模拟的影响研究

Exchange of surface layer turbulent fluxes is an important link in the process of land-atmosphere interaction. There is an important role in improving the simulation capacity of numerical models, especially of meteorological field in surface layer by study on surface layer turbulent flux parameterization schemes.The applicability of a non-iterative surface layer turbulent flux parameterization scheme developed by Hendrik Wouters (HW2012) will be analyzed by turbulence and gradient observation data over different underlying surface for one year. And then the coefficients of HW2012 scheme will be modified. . The revised HW2012 scheme will be introduced to WRF model, the calculation applicability of three surface layer turbulent flux parameterization schemes will be discussed in different stability condition over complex and uniform underlying surface by offline and online calculation with turbulent and gradient observation data. One of the three schemes is revised HW2012 scheme; the other two schemes are commonly used surface layer schemes of WRF model that are revised MM5 similarity theory scheme (Re-MM5-simi) and PleimXiu scheme (PX). . Three surface layer parameterization schemes such as HW2012 scheme, Re-MM5-simi scheme and PX scheme and two boundary layer parameterization schemes such as ACM2 scheme and YSU scheme will be used to simulate in complex and uniform underlying surface areas with high resolution by WRF model. The sensitivity research will be analyzed that is the impact of different surface layer parameterization schemes and boundary layer turbulent fluxes parameterization schemes on simulation applicability of wind speed.

近地层湍流通量交换是地气相互作用过程的重要环节，研究近地层湍流通量参数化方案对提高数值模式模拟能力、尤其是近地层气象场的模拟能力有重要作用。本项目拟采用不同下垫面条件下1年的湍流和梯度观测资料研究Hendrik Wouters的非迭代近地层湍流通量参数化方案(HW2012)的适用性，并对该方案的系数进行修正；将修正后HW2012方案引入到WRF模式中，基于实测资料离线和在线评估修正后HW2012方案和WRF模式常用的近地层参数化方案(修正的MM5相似理论方案，Re-MM5-simi；Pleim Xiu方案，PX)对复杂和均一下垫面不同稳定度下湍流通量的计算能力；在WRF模式中，采用近地层参数化方案(HW2012、Re-MM5-simi和PX)和边界层参数化方案(ACM2和YSU)的组合，对不同实验区进行高分辨率模拟，开展风速模拟效果对近地层湍流通量参数化方案和边界层方案的敏感性研究。

近地层湍流通量交换是地气相互作用过程的重要环节，研究近地层湍流通量参数化方案对提高数值模式模拟能力、尤其是近地层气象场的模拟能力有重要作用。.本项目采用不同下垫面条件下的湍流和梯度观测资料研究Hendrik Wouters的非迭代近地层湍流通量参数化方案(HW2012)的适用性，HW2012方案在鄱阳湖复杂地区冬季效果较好，夏季效果较差，HW2012方案在锡林浩特草原地区效果优于鄱阳湖复杂地区，且秋季效果要优于夏季；继而对该方案的系数进行修正，鄱阳湖复杂地区，稳定条件下采用系数7、2.76和24，不稳定条件下采用系数0.386和0.519；锡林浩特草原地区，稳定条件下采用系数7、2.76和0，不稳定条件下采用系数0.386和0.319。. 将修正后HW2012方案引入到WRF模式中，基于实测资料离线和在线评估修正后HW2012方案和WRF模式常用的近地层参数化方案(修正MM5相似理论方案，Re-MM5-simi；Pleim Xiu方案，PX)对复杂和均一下垫面不同稳定度下湍流通量的计算能力。基于实测资料离线评估显示：修正后的HW2012方案在鄱阳湖复杂地区和锡林浩特草原地区的通量计算效果均为最优；在WRF模式中在线评估，采用近地层参数化方案(HW2012、Re-MM5-simi和PX)和边界层参数化方案(ACM2和YSU)的组合，对不同实验区进行高分辨率模拟，开展近地层风速模拟效果对近地层参数化方案和边界层方案的敏感性研究。对鄱阳湖复杂地区和锡林浩特草原地区不同季节风速和气温的模拟效果对比分析来看，修正后的HW2012方案和ACM2方案组合的模拟效果均为最佳，不仅日变化趋势与实测更为接近，均方根误差也最小。