Investigation of the impacts of vegetation distribution and evaporative cooling on synthetic urban daytime climate using a coupled LES—LSM model
Investigation of the impacts of vegetation distribution and evaporative cooling on synthetic urban daytime climate using a coupled LES—LSM model
复制标题
使用 LES-LSM 耦合模型研究植被分布和蒸发冷却对合成城市白天气候的影响
DOI：
10.1002/hyp.7919
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发表时间：
2011
影响因子：
3.2
通讯作者：
Hsiao
中科院分区：
文献类型：
--
作者：
Hsin‐Yuan Huang;S. Margulis;C. R. Chu;Hsiao
白天对流边界层（CBL）内的动量和标量的陆-气相互作用强烈影响着当地的流动特性和区域天气或气候。在这项研究中，我们调查的影响，绿色空间尺度上的白天大气边界层（ABL）的合成城市域使用最近开发的大涡模拟陆面模式（LES-LSM）框架。利用真实的水深作为初始条件，对不同植被覆盖面积的人工城市地表进行了一系列数值试验。分析了模拟的微气象特征、地面通量、CBL基本特征和云分布。结果表明，参考层空气位温和比湿以及绿色空间的地表通量受城市域绿色空间尺度的显著影响。由于植被面积尺度的表面组织水平平均标量和动量剖面也有影响，但是，在这项研究中的幅度小于以前的研究使用一组离线的表面通量作为LES的下边界条件的结果。此外，即使本研究只进行白天的昼夜循环，绿色空间尺度对模拟中云分布的影响是显着的。具有更有组织的绿色空间的情况产生较低的升高积云和较大的云量，这影响了边界层顶部的能量收支，反过来，可能导致相对于长期天气和气候的额外表面冷却。版权所有© 2010约翰威利父子有限公司.
Local flow properties and regional weather or climate are strongly affected by land‐atmosphere interactions of momentum and scalars within the daytime convective boundary layer (CBL). In this study, we investigate the impact of green space scale on the daytime atmospheric boundary layer (ABL) over a synthetic urban domain using a recently developed large‐eddy simulation‐land surface model (LES–LSM) framework. With the use of realistic soundings as initial conditions, a series of numerical experiments over synthetic urban surfaces with varied scale of vegetated area is performed. Simulated micrometeorological properties, surface fluxes, basic CBL characteristics, and cloud distribution are analysed. The results show reference‐level air potential temperature and specific humidity as well as surface fluxes over green space are significantly affected by the scale of green space in the urban domain. The surface organization due to vegetated area scale also has impacts on horizontally averaged scalar and momentum profiles; however, the magnitude in this study is smaller than the results of a previous study using a set of offline surface fluxes as the lower boundary condition for LES. In addition, even though this study only performs a daytime diurnal cycle, the impact of green space scale on cloud distribution in simulations is significant. The cases with more organized green space yield lower‐elevated cumulus cloud and larger‐cloud cover fraction, which impacts the energy budget at the top of boundary layer and, in turn, could lead to additional surface cooling with respect to longer‐term weather and climate. Copyright © 2010 John Wiley & Sons, Ltd.