| 人为热对城市边界层结构影响研究 |
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| 引用本文： | 蒋维楣,陈燕.人为热对城市边界层结构影响研究[J].大气科学,2007,31(1):37-47. |
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| 作者姓名： | 蒋维楣 陈燕 |
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| 作者单位： | 南京大学大气科学系,南京,210093 |
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| 摘 要： | 为研究不同人为热源引入方案对城市边界层结构模拟性能的影响，以杭州地区为例，在区域边界层模式（RBLM）中引入一种新人为热源处理方案，即对城市中的人为热排放分层考虑，将低层的人为热源加入地表能量平衡方程，将高层人为热源分布与建筑物高度和密度联系起来，加入热量方程中，同时考虑了人为热源强度的日变化。数值试验结果表明，这是一种比较合理的处理方案。人为热源引入方案对城市边界层结构的影响表现在:气温、湍流动能增加，并通过湍流交换输送到较高层大气；大气不稳定度增加，混合层高度最高抬升了400 m；城市地区上升速度增加，热岛环流加强；白天人为热源一般为太阳辐射的10%～20%，对地气交换的影响较小。夜间没有了太阳辐射能量，对地气交换的影响比日间更明显；冬季低层湍流活动加强，湍能约增加40%，大气层结稳定度降低。
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| 关 键 词： | 人为热 地气交换 城市边界层结构 数值模拟 城市化 |
| 文章编号： | 1006-9895（2007）01-0037-11 |
| 修稿时间： | 2005-06-292005-09-14 |
The Impact of Anthropogenic Heat on Urban Boundary Layer Structure |
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| JIANG Wei-Mei and CHEN Yan.The Impact of Anthropogenic Heat on Urban Boundary Layer Structure[J].Chinese Journal of Atmospheric Sciences,2007,31(1):37-47. |
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| Authors: | JIANG Wei-Mei and CHEN Yan |
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| Institution: | Department of Atmospheric Sciences, Nanjing University, Nanjing 210093 |
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| Abstract: | The urbanization is a process that the human being changes the local natural surface characteristics widely and dramatically.This process will impact local atmospheric environment greatly.To understand the urbanization's effect on local urban boundary layer will show its great value in urban weather/climate study,urban environmental protection,urban design and construction,urban disaster-prevention,and will help us improve the residential environment and residential quality in urban area.A numerical simulation model is used in this paper to investigate the effect of the inhomogeneity of urban anthropogenic heat source on the exchanges of energy and material between surface and atmospheric system,and its impacts on urban boundary layer structures.To study the anthropogenic heat affecting the urban boundary layer structures,Hangzhou is taken as an example.A new anthropogenic heat source scheme is developed in the regional boundary layer numerical model(RBLM).In this new scheme,the urban anthropogenic heat source is distributed into different model layers.The lower layer heat release is added into the surface energy budget and the upper layer anthropogenic heat release is coupled into the atmosphere energy equations and its vertical distribution is related with the urban building distribution feature,including building height and density and the diurnal change of anthropogenic heat release is included in this scheme.The numerical simulation results show that this scheme can describe the anthropogenic heat release process better than former schemes and the simulated temperatures,wind directions,wind speeds are closer to the observation data.In the former anthropogenic heat release scheme all of the heat is added into the surface,this leads to the increasing of temperature and turbulence energy,and in the daytime this impact will be transported to upper atmosphere due to the strong turbulence and the increase of atmospheric temperature and turbulence is not obvious in lower air layer.The atmospheric instability increases and the boundary layer height increases by 400 m,the vertical speed over urban area is increased and urban heat island density is strengthened.In the nighttime the impact of anthropogenic heat is more obvious than in the daytime without the solar radiation heating.In the cases of the new scheme turbulence energy in lower layers increases by 40% and the atmospheric stability decreases.In general,the simulation results with the new anthropogenic heat release scheme show that the anthropogenic heat affects the urban boundary layer structure more greatly in the nighttime than in the daytime.And this impact is largest in winter,less in spring and autumn and weakest in summer.The reason may depend on that,in the surface energy budget the solar radiation is the main energy source,while anthropogenic heat is an important but not primary source.Compared with the diurnal and seasonal change of solar radiation,the anthropogenic heat release is assumed stable,so the fraction of urban anthropogenic heat in total energy that heats the surface skin and surface atmosphere is also diurnally and seasonally changeable,this causes the impact of the anthropogenic heat diurnally and seasonally. |
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| Keywords: | anthropogenic heat exchange between surface and atmosphere urban boundary layer structure numerical simulation urbanization |
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