南京与黄山两地气溶胶吸湿性研究
发布时间：2018-11-04 19:20
【摘要】：大气气溶胶的吸湿性对气溶胶粒子的谱分布、云凝结核形成、气候强迫、人体健康等均有重要的影响。南京和黄山作为两种不同的区域背景,具有明显不同的大气污染特征。本文利用2014年4、5月,2014年7月分别在南京和黄山对大气气溶胶吸湿性进行观测的结果,统计分析了南京黄山两地的气溶胶吸湿特性,同时结合黄山地区的水溶性离子采样信息,分析了化学组分信息对气溶胶吸湿性的影响,通过将HTDMA观测结果和分级采样化学组分信息相结合,计算了较宽粒径范围上的吸湿性参数κ。全文的主要结论如下：1)春季南京不同粒径气溶胶粒子的吸湿增长因子平均概率分布函数(GF-PDF)为双峰分布,由一个占主导地位的强吸湿模态和一个相对较小但仍很明显的弱吸湿模态组成,说明气溶胶粒子中同时含有较多的强吸湿颗粒和少部分弱吸湿颗粒。在90%相对湿度下,30-230nm各粒径段粒子平均吸湿增长因子分别为：1.26、1.32、1.29、1.30、1.29、1.28,随着气溶胶粒子的粒径增大,气溶胶吸湿性变化不大。黄山夏季不同粒径气溶胶粒子的吸湿增长因子平均概率分布函数(GF-PDF)主要呈现单峰和双峰分布,相比城市的多双峰分布,黄山地区的气溶胶粒子弱吸湿比例较低,表明黄山地区较城市背景空气更为清洁。85%相对湿度下,黄山地区70-230nm的气溶胶粒子平均吸湿增长因子分别为1.30、1.30、1.32、1.30、1.36,随着粒径增大,气溶胶粒子吸湿性有略微增大的趋势。对单双峰出现的时间统计发现,单峰情况多出现在下午,而双峰情况多出现在上午,说明环境气溶胶吸湿性受强弱吸湿比例的日变化影响,上午的气溶胶粒子外混合程度更高。南京与黄山两地不同粒径的气溶胶吸湿性对比发现,黄山地区气溶胶吸湿性大于南京,显示出清洁地区粒子吸湿性强于污染地区。黄山地区气溶胶粒子更趋向于内混合状态,化学组分更为单一,而南京的气溶胶粒子则外混合程度较高,化学组分信息会更为复杂。2)南京观测点对气溶胶吸湿性的日夜对比分析发现,整体上白天的气溶胶粒子吸湿性大于夜间气溶胶粒子吸湿性,白天强吸湿模态的粒子数目比例高于夜间,夜间气溶胶粒子的外混合程度更高,且粒径越大的粒子更趋向于外混合状态。对不同天气条件下的气溶胶粒子吸湿性统计发现,晴好天气可能由于光化学反应加速气溶胶老化导致气溶胶吸湿性更强,且更趋向于外混合状态。污染天气可能由于本地一次排放的弱吸湿性有机物较多而导致气溶胶吸湿性较低。不同气团来源的气溶胶吸湿性分析结果表明,来自西北大陆气团背景下爱根核模态粒子在经过大陆的长距离输送过程后,老化程度较高,吸湿性也更强。而对于积聚模态粒子,则为来自东方气团的粒子吸湿性更强。3)黄山地区高环境相对湿度(90%)下的气溶胶粒子吸湿性明显大于较低环境相对湿度(90%)的气溶胶粒子,说明高相对湿度可能加快气溶胶粒子的非均相化学反应速率和程度,导致气溶胶粒子吸湿性增强。不同气团来源的气溶胶吸湿性分析结果表明,局地气团下的气溶胶粒子吸湿性较高,来自东方气团的气溶胶粒子吸湿性最低,不同气团来源的气溶胶粒子吸湿性与硫酸盐含量有很大相关性。4)使用化学组分信息计算得到的平均吸湿性参数κ chem和HTDMA观测计算的κ HTDMA较为一致,硫酸铵是环境气溶胶粒子中最主要的吸湿性成分。利用分级化学采样数据,计算了全粒径范围(0.07～7.28μm)的气溶胶吸湿性参数κ与90%相对湿度下GF值,计算结果显示环境气溶胶的吸湿性分别在0.41μm和5.54μ m处各有一个峰值。
[Abstract]:The moisture absorption of atmospheric aerosols has an important influence on the distribution of aerosol particles, formation of cloud coagulum, climate forcing, human health and so on. As two different regional backgrounds, Nanjing and Huangshan have distinct characteristics of atmospheric pollution. Using April, May 2014 and July 2014, the aerosol moisture absorption characteristics of aerosol in Nanjing and Huangshan were analyzed statistically, and the water-soluble ion sampling information in Huangshan area was combined. The influence of chemical composition information on aerosol hygroscopicity was analyzed. The moisture absorption parameters were calculated by combining the results of HTDMA and the information of graded sampling chemistry. The main conclusions are as follows: 1) The average probability distribution function (GF-PDF) of different particle size aerosol particles in Nanjing in spring is bimodal distribution, which consists of a dominant strong moisture absorption mode and a relatively small but still very obvious weak moisture absorption mode. It is shown that the aerosol particles contain more strongly hygroscopic particles and a small proportion of weakly hygroscopic particles at the same time. At 90% relative humidity, the average moisture absorption and growth factors of each particle size section of 30-230nm were: 1. 26, 1. 32, 1. 29, 1. 30, 1. 29, 1. 28. With the increase of particle size of aerosol particles, aerosol hygroscopicity was not great. The average probability distribution function (GF-PDF) of different particle size aerosol particles in Huangshan in summer mainly presents single peak and double peak distribution. Compared with the urban multi-peak distribution, the weak moisture absorption ratio of aerosol particles in Huangshan area is lower. The average moisture absorption and growth factors of aerosol particles at 70-230nm in Huangshan area were 1. 30, 1. 30, 1. 32, 1. 30, 1. 36 respectively under 85% relative humidity. With the increase of particle size, the moisture absorption of aerosol particles increased slightly. It was found that the single peak appeared in the afternoon, and the double peak appeared in the morning, which showed that the moisture absorption of the environment was influenced by the diurnal variation of the moisture absorption ratio of the strong and weak, and the external mixing degree of the aerosol particles in the morning was higher. Compared with the aerosol hygroscopicity of different grain sizes in the two places of Nanjing and Huangshan, the moisture absorption of aerosol in Huangshan area is more than that of Nanjing, which shows that the moisture absorption in the cleaning area is stronger than that of the polluted area. aerosol particles in huangshan area tend to be in mixed state more, chemical components are more single, and aerosol particles in nanjing are more mixed and chemical component information is more complex. when the moisture absorption of the aerosol particles in the daytime is larger than that of the aerosol particles at night, the proportion of the particles in the daytime strong moisture absorption mode is higher than that of the night aerosol particles, the external mixing degree of the night aerosol particles is higher, and the particles with larger particle diameters tend to be mixed in an out-mixed state. It is found that fine weather may accelerate aerosol aging due to photochemical reaction, which results in stronger aerosol moisture absorption and more tendency to be mixed in an out-mixed state. The pollution weather may result in lower aerosol hygroscopicity due to the fact that the locally drained weak hygroscopic organic matter is much higher. The results of aerosol hydroscopic analysis of different air masses show that, from the background of the air masses in the Northwest China, the modal particles of the root nuclei have a higher degree of aging and stronger hygroscopicity after long-distance transportation through the continent. and for accumulating modal particles, the moisture absorption of aerosol particles in the high environmental relative humidity (90%) in the Huangshan area is obviously higher than that of the aerosol particles with relatively low ambient relative humidity (90%), It is suggested that high relative humidity may accelerate the rate and extent of heterogeneous chemical reactions of aerosol particles, which results in enhanced moisture absorption of aerosol particles. The results show that the moisture absorption of aerosol particles under local air mass is high, and the moisture absorption of aerosol particles from Oriental air mass is the lowest. The moisture absorption and sulfate content of aerosol particles derived from different gas masses have a great correlation. 4) The average moisture absorption parameters obtained by using the chemical composition information are consistent with that of HTDMA, which is the most important hygroscopic component in the environment aerosol particles. The results show that the moisture absorption of the environmental aerosol has a peak at 0. 41 & mu; m and 5.54 & mu; m, respectively.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X513
本文编号：2310901
[Abstract]:The moisture absorption of atmospheric aerosols has an important influence on the distribution of aerosol particles, formation of cloud coagulum, climate forcing, human health and so on. As two different regional backgrounds, Nanjing and Huangshan have distinct characteristics of atmospheric pollution. Using April, May 2014 and July 2014, the aerosol moisture absorption characteristics of aerosol in Nanjing and Huangshan were analyzed statistically, and the water-soluble ion sampling information in Huangshan area was combined. The influence of chemical composition information on aerosol hygroscopicity was analyzed. The moisture absorption parameters were calculated by combining the results of HTDMA and the information of graded sampling chemistry. The main conclusions are as follows: 1) The average probability distribution function (GF-PDF) of different particle size aerosol particles in Nanjing in spring is bimodal distribution, which consists of a dominant strong moisture absorption mode and a relatively small but still very obvious weak moisture absorption mode. It is shown that the aerosol particles contain more strongly hygroscopic particles and a small proportion of weakly hygroscopic particles at the same time. At 90% relative humidity, the average moisture absorption and growth factors of each particle size section of 30-230nm were: 1. 26, 1. 32, 1. 29, 1. 30, 1. 29, 1. 28. With the increase of particle size of aerosol particles, aerosol hygroscopicity was not great. The average probability distribution function (GF-PDF) of different particle size aerosol particles in Huangshan in summer mainly presents single peak and double peak distribution. Compared with the urban multi-peak distribution, the weak moisture absorption ratio of aerosol particles in Huangshan area is lower. The average moisture absorption and growth factors of aerosol particles at 70-230nm in Huangshan area were 1. 30, 1. 30, 1. 32, 1. 30, 1. 36 respectively under 85% relative humidity. With the increase of particle size, the moisture absorption of aerosol particles increased slightly. It was found that the single peak appeared in the afternoon, and the double peak appeared in the morning, which showed that the moisture absorption of the environment was influenced by the diurnal variation of the moisture absorption ratio of the strong and weak, and the external mixing degree of the aerosol particles in the morning was higher. Compared with the aerosol hygroscopicity of different grain sizes in the two places of Nanjing and Huangshan, the moisture absorption of aerosol in Huangshan area is more than that of Nanjing, which shows that the moisture absorption in the cleaning area is stronger than that of the polluted area. aerosol particles in huangshan area tend to be in mixed state more, chemical components are more single, and aerosol particles in nanjing are more mixed and chemical component information is more complex. when the moisture absorption of the aerosol particles in the daytime is larger than that of the aerosol particles at night, the proportion of the particles in the daytime strong moisture absorption mode is higher than that of the night aerosol particles, the external mixing degree of the night aerosol particles is higher, and the particles with larger particle diameters tend to be mixed in an out-mixed state. It is found that fine weather may accelerate aerosol aging due to photochemical reaction, which results in stronger aerosol moisture absorption and more tendency to be mixed in an out-mixed state. The pollution weather may result in lower aerosol hygroscopicity due to the fact that the locally drained weak hygroscopic organic matter is much higher. The results of aerosol hydroscopic analysis of different air masses show that, from the background of the air masses in the Northwest China, the modal particles of the root nuclei have a higher degree of aging and stronger hygroscopicity after long-distance transportation through the continent. and for accumulating modal particles, the moisture absorption of aerosol particles in the high environmental relative humidity (90%) in the Huangshan area is obviously higher than that of the aerosol particles with relatively low ambient relative humidity (90%), It is suggested that high relative humidity may accelerate the rate and extent of heterogeneous chemical reactions of aerosol particles, which results in enhanced moisture absorption of aerosol particles. The results show that the moisture absorption of aerosol particles under local air mass is high, and the moisture absorption of aerosol particles from Oriental air mass is the lowest. The moisture absorption and sulfate content of aerosol particles derived from different gas masses have a great correlation. 4) The average moisture absorption parameters obtained by using the chemical composition information are consistent with that of HTDMA, which is the most important hygroscopic component in the environment aerosol particles. The results show that the moisture absorption of the environmental aerosol has a peak at 0. 41 & mu; m and 5.54 & mu; m, respectively.
【学位授予单位】：南京信息工程大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：X513
【参考文献】
相关期刊论文 前3条
1 康汉青;朱彬;樊曙先;;南京北郊冬季大气气溶胶及其湿清除特征研究[J];气候与环境研究;2009年05期
2 黄鹂鸣,王格慧,王荟,高士祥,王连生;南京市空气中颗粒物PM10、PM2.5污染水平[J];中国环境科学;2002年04期
3 吴奕霄;银燕;顾雪松;谭浩波;汪亚;;南京北郊大气气溶胶的吸湿性观测研究[J];中国环境科学;2014年08期
，本文编号：2310901
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