湍流动能闭合方法在区域气候模式中的应用
TURBULENCE KINETIC ENERGY CLOSURE SCHEME APPLIED INTO REGIONAL CLIMATE MODELING
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摘要: 利用湍流动能闭合方法改进了区域气候模式(RegCM2)中边界层的参数化过程,并用资料进行了数值试验。结果表明.采用该方法可以较好地描述边界层的物理过程,温度、位势高度、比湿等物理量场的模拟均有不同程度的改善,提高了边界层计算的精度。该工作还对模式中边界层高度的计算作了改进,使边界层高度的日变化及高度极值都更符合实际情况。Abstract: The boundary layer parameterization scheme in regional climate model (RegCM2) is improved by applying turbulence kinetic energy (TKE) closure scheme.The NCEP/NCAR reanalysis data of 1991 is employed to test the effects of the TKE closure scheme on regional climate modeling.The results show:After employing TKE closure scheme.the physical process in boundary layer can be described more realistically.The simulation of the geo-potential height field and temperature field etc.are obviously improved,especially.the more distinct improvements occurs in the temperature field and specific humidity field of lower levels that are directly effect by boundary layer parameterization scheme.An improving can also be made on calculating the height of boundary layer,the result shows that the diurnal variation and the diurnal extreme of boundary layer height can be described more reasonable.