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题名 干旱区边界层对流及示踪物垂直传输的大涡模拟研究
姓名 王蓉
院系 大气科学学院
专业 大气物理学与大气环境
学位名称 理学硕士
外文题名 Study of large eddy simulation of boundary layer convection and vertical tracer transport in arid area
第一导师姓名 黄倩
关键词 大涡模拟;边界层对流;夹卷作用;热通量;风切变;覆盖逆温层;模式分辨率;示踪物抬升效率;传输高度;最小二乘法
外文关键词 Large Eddy Simulation;boundary layer convection;entrainment;heat flux;wind shear;overlying inversion layer;model resolution;tracer uplift rates;transport height;least-squares fit
学科 理学
摘要 我国西北干旱地区是沙尘暴的多发地区,沙尘暴的发生和发展所需要的物质(沙尘)和能量主要是通过大气边界层来输送和运作的,因此对干旱区大气边界层结构和演变特征及边界层对流的研究显得尤为重要。本论文利用“西北干旱区陆-气相互作用野外观测试验” 加密观测期间在敦煌站的观测资料和大涡模式(LEM),模拟研究了干旱区夏季超厚边界层的结构及演变特征,模拟的对流边界层平均位温与实测位温探空廓线有较好的一致性。通过一系列敏感性数值试验模拟分析了地表热通量、风切变、初始覆盖逆温强度以及模式分辨率对边界层对流的形式、强度及物理量分布的影响,进一步研究了边界层对流对示踪物抬升和垂直传输的影响,并分别定量地给出了地表热通量和风切变与示踪物抬升效率和传输高度关系的理论模型。
外文摘要 Boundary layer convection plays an important role in the transportation of heat, water vapor , momentum and aerosols. Sand-dust storms occur frequently in the arid region in Northwest China. It is very important to study the structure and the evolution of the boundary layer and boundary layer convection in arid area due to the energy and the material of a sand-dust storm being transported through the atmospheric boundary layer. Using observations measured in Dunhuang meteorological station during the intensive period of Land - atmosphere interaction field experiment over arid region of North-west China, together with a large eddy model (LEM), the structure and the evolution of the deep boundary layer in arid area in summer are investigated. The simulated convective boundary layer overall agrees with the observations. A series of numerical sensitivity experiments are performed to analyze the effects of the surface heat flux , wind shear, the initial inversion strength and model resolution on the formation and strength of convection and the distribution of the physical magnitude, and boundary layer convection on tracer uplift and transport. Theoretical models of quantitative relationship between surface heat flux and tracer uplift and transport, wind shear and tracer uplift and transport, respectively.
研究领域 大气边界层和沙尘传输
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