基于1980-2017年京津冀地区定时观测资料、欧亚陆面积雪资料、欧洲中期天气预报中心(European Centre for Medium-range Weather Forecasts,ECMWF)再分析资料,美国国家环境预报中心/大气研究中心(NCEP/NCAR)再分析资料以及英国哈德莱中...基于1980-2017年京津冀地区定时观测资料、欧亚陆面积雪资料、欧洲中期天气预报中心(European Centre for Medium-range Weather Forecasts,ECMWF)再分析资料,美国国家环境预报中心/大气研究中心(NCEP/NCAR)再分析资料以及英国哈德莱中心提供的海冰密集度资料,分析了秋季10-11月京津冀霾日频数年际变率与同期欧亚积雪的物理联系,并通过气候统计诊断和敏感性试验探讨了积雪异常影响京津冀10-11月霾日频数年际变率的可能机理。结果表明,10-11月京津冀霾日频数年际变率与同期东欧-西伯利亚平原地区(记为R Eu;50°~60°N,40°~80°E)积雪厚度和积雪覆盖度均呈现显著的正相关关系。R Eu积雪正异常与其西北侧的挪威海-巴伦支海海域以及北欧到东欧地区上空大气冷源密切联系,该冷源可激发一个自上述区域途经R Eu一直到东北亚的准正压大尺度纬向Rossby波列来调制影响京津冀霾日频数年际变率的关键环流系统,即东北亚异常反气旋。上述异常环流背景下,京津冀地区对流层低层为偏南风异常所控制,稳定大气层结易于建立,边界层高度偏低、地面风速偏弱且相对湿度偏高。该环境条件有利于霾天气发生发展,使得同期霾日偏多。作为预测信号,当前期9月楚科奇海-西波弗特海海冰偏少(多)时,10-11月京津冀霾日可能偏多(少)。展开更多
In the context of accelerated globalization,intercity factor flows are becoming in-creasingly dependent on a reasonable and orderly spatial structure.Therefore,an indepth study of the optimization and adjustment of sp...In the context of accelerated globalization,intercity factor flows are becoming in-creasingly dependent on a reasonable and orderly spatial structure.Therefore,an indepth study of the optimization and adjustment of spatial structure is essential for coordinated development.This study quantitatively evaluated urban development levels and introduced network analysis methods to analyse the spatial structure and robustness of development.The results indicated the following:(1)The urban development level in the Beijing-Tianjin-Hebei(BTH)region increased in all dimensions,and the transmission efficiency significantly improved.(2)The spatial structure of the BTH region has been relatively stable,as illustrated by the main pattern of the spatial distribution of central cities,with a trend towards contiguous development.(3)The ranking of network robustness is environment>society>economy,and the core network and key nodes are primarily located within the radiation of the three central cities of Beijing,Tianjin,and Shijiazhuang.(4)The coordinated development of the BTH region is effective but still needs to be optimized and adjusted,and the strategic significance of edge cities has not been completely exploited.This study aims to provide an emerging ana-lytical perspective for optimizing regional spatial structure and promoting regional coordinated development.展开更多
In China, volatile organic compound（VOC） control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were base...In China, volatile organic compound（VOC） control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts（EA）, but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore,this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing–Tianjin–Hebei region（BTH）, by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential（OFP） per ton VOC emission for these sources by using the maximum incremental reactivity（MIR） index as the characteristic of source reactivity（SR）. Then, we applied the data normalization method to respectively convert EA and SR to normalized EA（NEA） and normalized SR（NSR） for various sources in the BTH region.Finally, the control index（CI） was calculated, and these sources were further classified into four grades based on the normalized CI（NCI）. The study results showed that in the BTH region,furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI.展开更多
文摘基于1980-2017年京津冀地区定时观测资料、欧亚陆面积雪资料、欧洲中期天气预报中心(European Centre for Medium-range Weather Forecasts,ECMWF)再分析资料,美国国家环境预报中心/大气研究中心(NCEP/NCAR)再分析资料以及英国哈德莱中心提供的海冰密集度资料,分析了秋季10-11月京津冀霾日频数年际变率与同期欧亚积雪的物理联系,并通过气候统计诊断和敏感性试验探讨了积雪异常影响京津冀10-11月霾日频数年际变率的可能机理。结果表明,10-11月京津冀霾日频数年际变率与同期东欧-西伯利亚平原地区(记为R Eu;50°~60°N,40°~80°E)积雪厚度和积雪覆盖度均呈现显著的正相关关系。R Eu积雪正异常与其西北侧的挪威海-巴伦支海海域以及北欧到东欧地区上空大气冷源密切联系,该冷源可激发一个自上述区域途经R Eu一直到东北亚的准正压大尺度纬向Rossby波列来调制影响京津冀霾日频数年际变率的关键环流系统,即东北亚异常反气旋。上述异常环流背景下,京津冀地区对流层低层为偏南风异常所控制,稳定大气层结易于建立,边界层高度偏低、地面风速偏弱且相对湿度偏高。该环境条件有利于霾天气发生发展,使得同期霾日偏多。作为预测信号,当前期9月楚科奇海-西波弗特海海冰偏少(多)时,10-11月京津冀霾日可能偏多(少)。
基金National Key Research and Development Program,No.2023YFC3804001Natural Resources Planning and Management Project,No.A2417,No.A2418。
文摘In the context of accelerated globalization,intercity factor flows are becoming in-creasingly dependent on a reasonable and orderly spatial structure.Therefore,an indepth study of the optimization and adjustment of spatial structure is essential for coordinated development.This study quantitatively evaluated urban development levels and introduced network analysis methods to analyse the spatial structure and robustness of development.The results indicated the following:(1)The urban development level in the Beijing-Tianjin-Hebei(BTH)region increased in all dimensions,and the transmission efficiency significantly improved.(2)The spatial structure of the BTH region has been relatively stable,as illustrated by the main pattern of the spatial distribution of central cities,with a trend towards contiguous development.(3)The ranking of network robustness is environment>society>economy,and the core network and key nodes are primarily located within the radiation of the three central cities of Beijing,Tianjin,and Shijiazhuang.(4)The coordinated development of the BTH region is effective but still needs to be optimized and adjusted,and the strategic significance of edge cities has not been completely exploited.This study aims to provide an emerging ana-lytical perspective for optimizing regional spatial structure and promoting regional coordinated development.
基金supported by the National Key Technology Support Program of China(Nos.2014BAC23B05&2014BAC23B02)the Natural Sciences Foundation of China(No.51478017)+1 种基金the Youth Individual Project of Beijing Talents Training Fund(No.2015000021733G170)the Ministry of Environmental Protection Special Funds for Scientific Research on Public Causes(No.201409016)
文摘In China, volatile organic compound（VOC） control directives have been continuously released and implemented for important sources and regions to tackle air pollution. The corresponding control requirements were based on VOC emission amounts（EA）, but never considered the significant differentiation of VOC species in terms of atmospheric chemical reactivity. This will adversely influence the effect of VOC reduction on air quality improvement. Therefore,this study attempted to develop a comprehensive classification method for typical VOC sources in the Beijing–Tianjin–Hebei region（BTH）, by combining the VOC emission amounts with the chemical reactivities of VOC species. Firstly, we obtained the VOC chemical profiles by measuring 5 key sources in the BTH region and referencing another 10 key sources, and estimated the ozone formation potential（OFP） per ton VOC emission for these sources by using the maximum incremental reactivity（MIR） index as the characteristic of source reactivity（SR）. Then, we applied the data normalization method to respectively convert EA and SR to normalized EA（NEA） and normalized SR（NSR） for various sources in the BTH region.Finally, the control index（CI） was calculated, and these sources were further classified into four grades based on the normalized CI（NCI）. The study results showed that in the BTH region,furniture coating, automobile coating, and road vehicles are characterized by high NCI and need to be given more attention; however, the petro-chemical industry, which was designated as an important control source by air quality managers, has a lower NCI.
