• CN 62-1175/P
• ISSN 1006-7639

### Effect of Large Eddy Horizontal Resolution on Simulation of Entrainment and Tracer Vertical Transport

1. 1. Gansu Weather Modification Office, Lanzhou 730020, China；2. Key Laboratory for Semi-Arid Climate
Change of the Ministry Education, College of Atmospheric Sciences, Lanzhou University, Lanzhou 730000, China；
3. Institute of Arid Meteorology, China Meteorological Administration, Key Laboratory of Arid Climate
Change and Reducing Disaster of Gansu Province, Lanzhou 730020, China
• Online:2019-02-28 Published:2019-02-28

### 大涡模式水平分辨率对边界层夹卷过程及示踪物垂直传输的影响

1. 1.甘肃省人工影响天气办公室,甘肃兰州730020；2.兰州大学大气科学学院,
半干旱气候变化教育部重点实验室,甘肃兰州730000；3. 中国气象局兰州
干旱气象研究所，甘肃省干旱气候变化与减灾重点实验室,甘肃兰州730020
• 作者简介:王蓉 （1989— ）， 女， 硕士研究生， 工程师， 主要从事边界层湍流及沙尘传输等研究. E-mail: 13679418316@163.com。
• 基金资助:

国家自然科学基金重大研究计划（91637106）、干旱气象科学研究基金项目（IAM201813）、国家自然科学基金面上项目（41575008）和甘肃省气象局气象科研面上项目(GSMAMs2018-16)共同资助

Abstract:

:The effects of horizontal resolution of the model on convection, entrainment process and vertical transmission of tracers in boundary layer were studied by using the field intensive observation data in Dunhuang arid area and large eddy model (LEM). The results show when the horizontal resolution of the model was improved, the more the number of convection bubbles, the smaller the scale and the stronger the convection intensity in the boundary layer were simulated. And the potential temperature variance increased, the horizontal velocity variance decreased, the vertical velocity variance increased, and the upward cold flow contributed the most to the heat flux in the entrainment layer. The higher the model horizontal resolution was, the wider the distribution range of probability density functions (PDF) of vertical velocity, potential temperature and tracer concentration were, and the more distinct the subtle variation characteristics were. In addition, the spatial distribution of tracer was simulated to be more detailed and the tracer transport was also higher with increasing the horizontal resolution of the model. Considering the greater noise generated in the simulation process and the longer computing time in the high resolution simulations, the use of 200 m grid spacing as LEM horizontal resolution in simulating was an ideal choice, which could not only simulate the average structure of the boundary layer convection, but also the smaller distribution of the boundary layer turbulence could be simulated.

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