摘要
地表/冠层城市热岛(SUHI/CUHI)效应与大气/近地表城市污岛(AUPI/NSUPI)效应相互作用、相互影响,对城市生态环境安全造成了极大的威胁。利用地温、气温、气溶胶光学厚度、PM_(2.5)数据,基于空间耦合性分析和归因量化估算方法,对2003—2020年西安市辐射效应下AUPI对SUHI、湍流混合下CUHI对NSUPI的作用关系进行研究。结果表明:(1)由于冬季气溶胶辐射效应存在昼夜差异,冬季白天SUHI强度小于-0.2 K,气溶胶辐射冷却效应强导致城市地温低,城市比乡村冷;而夜晚SUHI强度大于2.2 K,气溶胶长波辐射效应增强,悬浮在城市空间的污染物颗粒成为城市的“保温层”;(2)春、夏季CUHI持续增强时,湍流混合作用加强导致近地表污染物颗粒扩散,城市PM_(2.5)浓度与NSUPI强度均降低;秋、冬季由于大气逆温层的影响,阻碍了由CUHI效应驱动的空气上升湍流运动,在近地表区域PM_(2.5)颗粒聚集、堆积,NSUPI随之增强。(3)归因分析雾霾对地表热岛的贡献值表明,夜晚气溶胶光学厚度(AOD)均与SUHI呈显著负相关,相关系数分别为-0.431、-0.386,雾霾对夜晚地表热环境主要为辐射降温效应,而对城市热岛局地气候的减弱或增强作用主要归因于城乡AOD的正负差值。城市热岛效应与污岛效应的变化密不可分,因此推进城市气候和城市污染的综合性研究对绿色城市生态环境建设具有十分重要的意义。
Surface/Canopy Urban Heat Island(SUHI/CUHI)effect and Atmospheric/Near-surface Urban Pollution Island(AUPI/NSUPI)effect interact and influence each other,significantly threatening the urban ecological environment.Based on the spatial coupling analysis and attribution method,the impact of AUPI on SUHI under radiation effect and CUHI on NSUPI under turbulence mixing in Xi’an city from 2003 to 2020 were explored using land surface temperature,air temperature,Aerosol Optical Depth(AOD),and PM_(2.5)data.The results indicated that:(1)Due to the difference in aerosol radiation effect between day and night in winter,SUHI intensity in winter is<0.2 K.The strong aerosol radiation cooling effect causes low ground temperature in urban areas and cooler in urban areas than in rural areas.When the SUHI intensity is greater than 2.2 K at night,the long-wave radiation effect of aerosol is enhanced,and the pollutant particles suspended in the urban space become the“insulation layer”of the city.(2)Significant CUHI in spring and summer enhanced atmosphere turbulent mixing,causing the diffusion of pollutant particles near the surface in urban regions.PM_(2.5)concentration and NSUPI intensity decreased correspondingly on urban surfaces.In autumn and winter,the atmospheric inversion layer obstructed air ascending movement driven by the CUHI effect.PM_(2.5)particles aggregated and accumulated in near-surface urban areas,and NSUPI was enhanced accordingly.Additionally,the contribution of haze to surface heat island by attribution quantitative analysis suggested that AOD in rural or urban areas was significantly negatively correlated with SUHI at night and correlation coefficients were-0.431 and-0.386,respectively.This suggested that the main radiation effect of haze on the surface heat environment at night was the cooling effect,while the weakening or strengthening effect of haze on the local climate of urban heat islands was mainly attributed to the positive or negative difference in AOD in urban and rural areas.The UHI and UPI effects are inseparable.It is very important to promote the comprehensive study of urban climate and pollution for constructing a green urban ecological environment.
作者
蒋子琪
王旭红
冯子豪
崔思颖
杨霞
JIANG Ziqi;WANG Xuhong;FENG Zihao;CUI Siying;YANG Xia(College of Urban and Environmental Sciences,Northwest University,Xi’an 710127,Shaanxi,China;Shaanxi Provincial Key Laboratory of Surface System and Environmental Carrying Capacity,Xi’an 710127,Shaanxi,China;Xi’an Urban Ecosystem Positioning Observation and Research Station,Xi’an 710127,Shaanxi,China)
出处
《干旱区研究》
CSCD
北大核心
2022年第6期1768-1781,共14页
Arid Zone Research
基金
国家自然科学基金(41971387)
陕西省自然科学基础研究计划(2020JM-430)。
关键词
西安市
地表/冠层城市热岛
大气/近地表城市污岛
空间耦合性分析
归因方法
Xi’an
surface/canopy urban heat island
atmospheric/near-surface pollution island
spatial coupling analysis
attribution method
