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DOI	10.1016/j.agrformet.2020.108288
	Tree model with drag, transpiration, shading and deposition: Identification of cooling regimes and large-eddy simulation
	Grylls, Tom; van Reeuwijk, Maarten
通讯作者	Grylls, T (corresponding author), Imperial Coll London, Dept Civil & Environm Engn, London SW7 2AZ, England.
来源期刊	AGRICULTURAL AND FOREST METEOROLOGY
ISSN	0168-1923
EISSN	1873-2240
出版年	2021
卷号	298
英文摘要	Trees play an important role in the urban heat island effect and urban air quality due to their impact on the transfer of radiation, momentum, heat, moisture and pollution. However, the effects of trees are hard to quantify due to their complex interactions with urban surfaces and the turbulent atmosphere overhead. We present a complete tree model for large-eddy simulations (LES) that represents the effects of trees on drag, transpiration, shading and deposition at resolutions of O(1 m, 0.1 s) whilst minimising the number of model parameters. The tree model avoids the necessity to resolve the leaf temperature via a derivation of the Penman-Monteith equation and distinguishes between cooling via transpiration and shading. The latent heat flux is further broken down into radiative and advective components in order to better understand the mechanism behind transpirational cooling (e.g. the 'oasis' effect). The new tree model is investigated analytically to provide insight into tree cooling regimes, and is applied to field studies to contextualise the analysis. The combined cooling effect of trees due to transpiration and shading processes can be reduced to a four-dimensional parameter space. The net tree cooling (NTC) and tree cooling ratio (TCR) parameters are defined to enable a systematic categorisation of the thermal effect of a tree into five regimes: net heating, net reduction (shading dominated), net reduction (transpiration dominated), net cooling (shading dominated) and net cooling (transpiration dominated). Existing parameterisations for tree cooling are reviewed, illustrating their limitations and highlighting the need for complete models to determine tree cooling. The tree model is implemented into the LES model uDALES. The drag and canopy energy balance models are validated, and results are presented for domains that are 1) fully covered by trees; 2) partially covered by trees; and 3) have a single line of trees. These simulations provide physical insight into the effect of trees on the microclimate and provide evaluation data for future studies.
英文关键词	Trees Urban Pollution Shading Transpiration Deposition Cooling regimes Large-eddy simulation
类型	Article
语种	英语
收录类别	SCI-E
WOS记录号	WOS:000610797100010
WOS关键词	URBAN STREET CANYON ; POLLUTANT DISPERSION ; TURBULENT-FLOW ; GREEN INFRASTRUCTURE ; BOUNDARY-LAYER ; AIR-POLLUTION ; HEAT-STORAGE ; LEAF ; CANOPY ; VEGETATION
WOS类目	Agronomy ; Forestry ; Meteorology & Atmospheric Sciences
WOS研究方向	Agriculture ; Forestry ; Meteorology & Atmospheric Sciences
资源类型	期刊论文
条目标识符	http://119.78.100.177/qdio/handle/2XILL650/347620
作者单位	[Grylls, Tom; van Reeuwijk, Maarten] Imperial Coll London, Dept Civil & Environm Engn, London SW7 2AZ, England
推荐引用方式 GB/T 7714	Grylls, Tom,van Reeuwijk, Maarten. Tree model with drag, transpiration, shading and deposition: Identification of cooling regimes and large-eddy simulation[J],2021,298.
APA	Grylls, Tom,&van Reeuwijk, Maarten.(2021).Tree model with drag, transpiration, shading and deposition: Identification of cooling regimes and large-eddy simulation.AGRICULTURAL AND FOREST METEOROLOGY,298.
MLA	Grylls, Tom,et al."Tree model with drag, transpiration, shading and deposition: Identification of cooling regimes and large-eddy simulation".AGRICULTURAL AND FOREST METEOROLOGY 298(2021).