复杂下垫面地域边界层结构的三维细网格数值模拟

NUMERICAL SIMULATION WITH 3-DFINE-MESH ON THE STRUCTURE OF THE ATMOSPHERIC BOUNDARY LAYER OVER COMPLEX UNDERLYING REGIONS

建立了一个可供复杂下垫面地域使用的非静力的三维细网格边界层模式，就复杂下垫面条件下的边界层结构和湍流特征作了以实例为比照的数值模拟试验，模式采用能量（Ｅ－ε）闭合方案，舍弃了静力近似。以实测资料为初始输入，同时还做了一些数值试验，分别获得了采用静力与非静力模式和不同闭合方案对ＰＢＬ模拟的结果。结果表明，复杂下垫面地域的陡峭地形和不规则海岸线对局地风场和湍流场影响很大，在此类条件下，采用非静力模式是必要的。

In this paper, a 3 dimensional fine mesh nonhydrostatic PBL model has been developed and used for numerical simulation on the PBL structure and turbulence characteristics over complex underlying regions. Some results from this model were in agreement with those from observation. Energy closure scheme(E ε) was used. The initial fields used in this model were from observed data. Some numerical experiments were also done and effects on PBL simulation,under the conditions of using nonhydrostatic model or not and different closure schemes,were obtained.The results indicated that abrupt terrain and irregular coasts had more effects on the local wind fields and turbulence fields, and it was necessary to use nonhydrostatic model for complex underlying regions, and energy closure scheme could simulate turbulence diffusoin better than K closure scheme in the complex airflow.