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学术报告

【8月7日10:30】中山大学刘少锋副教授:Further improvement of surface flux estimation in the unstable surface layer based on LES data

兰州大学110周年校庆学术活动之澳门真人线上学术报告:
  应澳门真人线上、西部灾害与环境力学教育部重点实验室黄宁教授、张洁青年教授邀请,中山大学刘少锋副教授于2019年8月6-7日来我校进行学术交流并做学术报告,欢迎广大师生参加。

  • 报告题目:Further improvement of surface flux estimation in the unstable surface layer based on LES data
  • 人:刘少锋 副教授
  • 报告时间:2019年8月7日(星期三)10:30-11:30
  • 报告地点:祁连堂322学术报告厅
  • 人:
报告人简介

刘少锋,中山大学大气科学学院副教授,中山大学“百人计划”青年杰出人才。2002年本科毕业于南京信息工程大学(原南京气象学院),2008年毕业于中科院大气物理研究所,获理学博士学位,后留所工作,任助理研究员。2010年到德国科隆大学访问,2011年3月起正式在德国科隆大学工作,任研究科学家。2017年5月起在中山大学大气科学学院工作。主要从事陆面过程、边界层湍流、环境模拟等方面的研究。目前正主持国家自然科学基金面上项目一项、中山大学百人计划项目一项,曾主持国家自然科学基金青年项目,参加国家863计划、德国DFG 、国家重点研发计划、国家自然科学基金重点项目等多个项目,发表高水平学术论文10多篇。

报告摘要

The Monin-Obukhov similarity theory (MOST) is widely used for the surface turbulence flux-gradient relations in modeling and data analysis. Here we quantify multi-scale turbulence processes by applying our newly developed analysis technique to large-eddy simulation data, and find that in the unstable surface layer, large convective eddies (with the scaling of boundary layer depth) and local free convection exist in addition to small eddies. An empirical MOST function (considering the last two processes only) is found to underestimate the surface friction velocity and heat flux both by about 30%. Much better results can be obtained using a function that explicitly considers all three processes. Generally, the non-dimensional wind shear exhibits larger scatter and deviates more from the MOST than the temperature gradient. Based on these results, we propose the revised Sorbjan (1986) function (with coefficients determined from this study) for wind shear and MOST function for temperature gradient, for estimating surface fluxes in the unstable surface layer. The three-dimensional multi-scale analysis method we develop in this study is of general nature and can be of interest for problems of three-dimensional multi-scale process description in other disciplines.