基于腔衰荡光谱技术的气溶胶消光仪的研制与应用
发布时间：2018-10-17 22:23
【摘要】：气溶胶作为大气污染的主要成分,不仅可通过散射和吸收辐射直接影响地球大气辐射平衡,还可通过影响云的光学特性和云的寿命间接影响地球辐射平衡。近年来,气溶胶引起的直接辐射强迫成为全球研究的热点。因此,准确了解不同区域气溶胶的光学特性,对于减少气溶胶辐射强迫的不确定性具有重要意义。腔衰荡光谱(Cavity Ring-Down Spectroscopy,CRDS)技术因其具有长达数千米甚至数十千米的等效光程,具有超高灵敏度和低检测限的优点,被认为是进行气溶胶消光特性研究的有效手段。本文基于已有的CRDS技术理论的气溶胶消光仪的技术方案,完成了可用于测量大气气溶胶消光系数的气溶胶消光仪的研制及性能表征,并以昆山阳澄湖畔的实际大气气溶胶为研究对象,分析研究了测点的大气气溶胶的消光特性及相对湿度对消光特性的影响。本论文的主要研究成果主要集中在以下几个方面:(1)国内率先研制了基于CRDS技术的用于测量气溶胶消光特性的气溶胶消光仪,测量了实验室条件下产生的聚苯乙烯标准颗粒物的消光截面,得到了实验室条件下标准颗粒物的不确定性小于3%,验证了系统的可靠性。(2)对气溶胶消光仪的性能指标进行了表征:仪器的背景衰荡时间为51.26μs,消光系数的最低检测限可达到10-7m-1量级,响应时间小于2min。气溶胶消光仪的性能优异,能够实现对大气气溶胶消光系数的高灵敏度、快速、自动在线检测,可用于环境大气监测领域的大气气溶胶消光系数的实时在线监测。(3)以昆山阳澄湖畔的实际大气气溶胶为研究对象,通过长时间连续测量,结合气象因子的统计结果,详细分析了监测点的气溶胶消光特性及其日变化规律。观测结果表明,气象条件及周边的强污染源对测点的大气气溶胶消光系数影响较大。(4)为了研究相对湿度对气溶胶消光系数的影响,利用两台仪器同时测量了不同相对湿度下实际大气中的气溶胶的消光系数,通过使用亲水参数γ值对测点环境相对湿度对气溶胶消光系数的影响进行了初步研究。
[Abstract]:Aerosol, as the main component of atmospheric pollution, can not only directly affect the earth's atmospheric radiation balance by scattering and absorbing radiation, but also indirectly affect the earth's radiation balance through the influence of cloud optical properties and cloud lifetime. In recent years, aerosol induced direct radiative forcing has become a global research hotspot. Therefore, it is important to understand the optical properties of aerosols in different regions to reduce the uncertainty of aerosol radiative forcing. Cavity ring-down spectroscopy (Cavity Ring-Down Spectroscopy,CRDS) is considered to be an effective method for the study of aerosol extinction due to its high sensitivity and low detection limit due to its equivalent optical path of several kilometers or even tens of kilometers. Based on the technical scheme of aerosol extinction instrument based on CRDS theory, the development and performance characterization of aerosol extinction instrument which can be used to measure atmospheric aerosol extinction coefficient have been completed in this paper. Taking the actual atmospheric aerosol in Yangcheng Lake in Kunshan as the research object, the extinction characteristics of atmospheric aerosol and the effect of relative humidity on the extinction characteristics were analyzed and studied. The main research results of this thesis are as follows: (1) the aerosol extinction instrument based on CRDS technology is developed firstly in China, which is used to measure the extinction characteristics of aerosol. The extinction cross sections of standard polystyrene particles produced under laboratory conditions were measured. The uncertainty of standard particulate matter in laboratory is less than 3, which verifies the reliability of the system. (2) the performance index of aerosol extinction instrument is characterized: the background decay time is 51.26 渭 s, and the lowest detection of extinction coefficient is obtained. The limit can be as high as 10-7m-1, The response time is less than 2 min. The aerosol extinction instrument has excellent performance and can achieve high sensitivity, fast and automatic on-line detection of atmospheric aerosol extinction coefficient. It can be used for real-time on-line monitoring of atmospheric aerosol extinction coefficient in the field of environmental atmospheric monitoring. (3) taking the actual atmospheric aerosol near Yangcheng Lake in Kunshan as the research object, the atmospheric aerosol is measured continuously for a long time and combined with the statistical results of meteorological factors. The characteristics of aerosol extinction and its diurnal variation are analyzed in detail. The results show that the atmospheric aerosol extinction coefficient is greatly affected by meteorological conditions and the surrounding strong pollution sources. (4) in order to study the effect of relative humidity on aerosol extinction coefficient, The extinction coefficient of aerosol at different relative humidity was measured simultaneously by two instruments. The effect of environmental relative humidity on extinction coefficient of aerosol was studied by using hydrophilic parameter 纬 value.
【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X851
本文编号：2278212
[Abstract]:Aerosol, as the main component of atmospheric pollution, can not only directly affect the earth's atmospheric radiation balance by scattering and absorbing radiation, but also indirectly affect the earth's radiation balance through the influence of cloud optical properties and cloud lifetime. In recent years, aerosol induced direct radiative forcing has become a global research hotspot. Therefore, it is important to understand the optical properties of aerosols in different regions to reduce the uncertainty of aerosol radiative forcing. Cavity ring-down spectroscopy (Cavity Ring-Down Spectroscopy,CRDS) is considered to be an effective method for the study of aerosol extinction due to its high sensitivity and low detection limit due to its equivalent optical path of several kilometers or even tens of kilometers. Based on the technical scheme of aerosol extinction instrument based on CRDS theory, the development and performance characterization of aerosol extinction instrument which can be used to measure atmospheric aerosol extinction coefficient have been completed in this paper. Taking the actual atmospheric aerosol in Yangcheng Lake in Kunshan as the research object, the extinction characteristics of atmospheric aerosol and the effect of relative humidity on the extinction characteristics were analyzed and studied. The main research results of this thesis are as follows: (1) the aerosol extinction instrument based on CRDS technology is developed firstly in China, which is used to measure the extinction characteristics of aerosol. The extinction cross sections of standard polystyrene particles produced under laboratory conditions were measured. The uncertainty of standard particulate matter in laboratory is less than 3, which verifies the reliability of the system. (2) the performance index of aerosol extinction instrument is characterized: the background decay time is 51.26 渭 s, and the lowest detection of extinction coefficient is obtained. The limit can be as high as 10-7m-1, The response time is less than 2 min. The aerosol extinction instrument has excellent performance and can achieve high sensitivity, fast and automatic on-line detection of atmospheric aerosol extinction coefficient. It can be used for real-time on-line monitoring of atmospheric aerosol extinction coefficient in the field of environmental atmospheric monitoring. (3) taking the actual atmospheric aerosol near Yangcheng Lake in Kunshan as the research object, the atmospheric aerosol is measured continuously for a long time and combined with the statistical results of meteorological factors. The characteristics of aerosol extinction and its diurnal variation are analyzed in detail. The results show that the atmospheric aerosol extinction coefficient is greatly affected by meteorological conditions and the surrounding strong pollution sources. (4) in order to study the effect of relative humidity on aerosol extinction coefficient, The extinction coefficient of aerosol at different relative humidity was measured simultaneously by two instruments. The effect of environmental relative humidity on extinction coefficient of aerosol was studied by using hydrophilic parameter 纬 value.
【学位授予单位】：上海大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X851
【引证文献】
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1 李学彬;徐青山;魏合理;胡欢陵;;相对湿度与能见度的相关性研究[A];中国气象学会2007年年会气象综合探测技术分会场论文集[C];2007年
，本文编号：2278212
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