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The Effect of Land Surface Heterogeneity on the Atmospheric Boundary-Layer Structure and Measurements

地表非均质性对大气边界层结构的影响及测量

基本信息

批准号：
117404101
负责人：
Professor Dr. Jens Bange
金额：
--
依托单位：
Institut für Meteorologie und Klimatologie
依托单位国家：
德国
项目类别：
Research Grants
财政年份：
2009
资助国家：
德国
起止时间：
2008-12-31 至 2013-12-31
项目状态：
已结题

来源：
https://gepris.dfg.de/gepris/projekt/117404101?language=en
关键词：
Effect Land Surface Heterogeneity Atmospheric

项目摘要

An comprehensive experimental data set on the structure of the atmospheric boundary layer (ABL) over a heterogeneous land surface has been collected during the LITFASS-2003 experiment. This campaign was realised within the EVA GRIPS (Evaporation at Grid and Pixel Scale) project of the German Climate Research Program (DEKLIM). Measurements included the operation of 14 surface flux stations, two eddy-covariance systems at a 99 m tower, three large-aperture scintillometers (LAS) and the performance of 35 low-level flights using the Helipod, a turbulence probe carried by a Helicopter. Within EVA GRIPS (which expired in 2004), the experimental data have been analysed with respect to the determination of area-averaged values of evaporation.With the present proposal we aim at a further analysis of the LITFASS-2003 data set in order to remove existing deficits concerning our understanding of the turbulent ABL structure and processes over a heterogeneous land surface. The following issues shall be investigated:1. What is the relative importance of terrain heterogeneity, heterogeneous land use and heterogeneous atmospheric forcing on the ABL structure?2. On which conditions and at which levels does horizontal mixing occur in the ABL over a heterogeneous land surface?3. Can heterogeneity effects at different spatial scales explain the non-closed surface energy balance?4. How do different time scales, scalar similarity and thermally-induced secondary circulations influence turbulent flux measurements, and what are the implications for the parameterisation of turbulent fluxes in atmospheric models?Analysis of experimental data will be supported by a further interpretation of data from Large-Eddy Simulation (LES) runs already completed and by the performance of new LES runs set up specifically in light of our previous findings and specific research aims. Finally, implications for measurement, data analysis and modelling strategies shall be derived, including recommendations for a suitable set-up and siting of surface layer and profile measurement systems in a heterogeneous landscape. The experiment strategy shall be supplemented by a methodology to appropriately correct local turbulent surface fluxes in order to achieve closure of the surface energy balance.

在LITFASS-2003实验期间，收集了一组关于非均匀陆面大气边界层结构的综合实验数据。这一运动是在德国气候研究计划（DEKLIM）的伊娃GRIPS（网格和像素尺度蒸发）项目中实现的。测量工作包括14个地面通量站的运行、99米高的塔上的两个涡度协方差系统、三个大孔径风速仪和使用直升机携带的湍流探测器Helipod进行的35次低空飞行。在伊娃GRIPS（已于2004年到期），实验数据进行了分析方面的面积平均值的evaporation.With目前的建议，我们的目标是进一步分析的LITFASS-2003数据集，以消除现有的赤字，我们了解的湍流ABL结构和过程在一个异质的陆地表面。应调查以下问题：1。地形异质性、土地利用异质性和大气强迫异质性对大气边界层结构的相对重要性是什么？2.在非均匀陆面的大气边界层中，水平混合在什么条件和什么水平上发生？3.不同空间尺度的异质性效应能否解释非闭合的地表能量平衡？4.不同的时间尺度、标量相似性和热诱导二次环流如何影响湍流通量测量，以及大气模式中湍流通量参数化的含义是什么？实验数据的分析将得到支持的进一步解释的数据从大涡模拟（LES）运行已经完成，并通过新的LES运行的性能，特别是根据我们以前的研究结果和具体的研究目标。最后，测量，数据分析和建模策略的影响，应得出，包括建议一个合适的设置和选址的表层和剖面测量系统在一个异质景观。实验策略应辅以适当纠正局部湍流表面通量的方法，以实现表面能量平衡的闭合。