【摘要】：隨著經(jīng)濟規(guī)模不斷擴大,城市化節(jié)奏越來越快,汽車數(shù)量大規(guī)模增加,人類生產(chǎn)活動造成細(xì)粒子氣溶膠污染現(xiàn)象不斷加重,灰霾天氣日益增加,在國內(nèi)存在四個灰霾現(xiàn)象較為嚴(yán)重的地域:京津唐地區(qū)、四川盆地、珠三角以及長江三角洲地域,表現(xiàn)出產(chǎn)生頻率逐漸增加、成霾面積不斷擴大的特征。像北上廣等地,全年不止1/3天數(shù)都是灰霾天氣,更有甚者超過一半。而面對細(xì)粒子本身體積小、質(zhì)量輕、較難沉降和濾除的特點,沙塵、灰霾等大氣渾濁現(xiàn)象很難得到有效控制。因此,人類的生存生活和地球氣候環(huán)境嚴(yán)重受到影響,為此對灰霾、沙塵等高濃度氣溶膠的研究成為目前討論的熱點,引起了科學(xué)界高度重視。本文主要從以下幾個方面討論了灰霾等高濃度氣溶膠條件下的有關(guān)散射傳輸問題的研究進展;(1)大氣氣溶膠粒子的物理光學(xué)特性;(2)粒子吸濕變化對粒子散射傳輸?shù)挠绊?(3)氣溶膠偏振反射特性;(4)地氣間多次散射問題,高濃度氣溶膠條背景下矢量輻射傳輸建模的研究。同時,由于大氣氣溶膠對光線有散射和吸收作用,其消光效應(yīng)直接影響大氣的能見度,相關(guān)的散射理論有:瑞利散射,米散射,以及非球形粒子的T矩陣方法和DDA理論等等�；姻舶l(fā)生時微粒(D2.5μm)中水溶性離子NH4+、NO3-和SO42-的濃度遠(yuǎn)大于正常天氣,它們是PM2.5的主要化學(xué)成分,主要以銨鹽的形式存在。這些高濃度的銨鹽有利于生成二次顆粒物,造成能見度低下,促使灰霾形成,因此,灰霾期間顆粒物較非灰霾日偏酸性,除此之外,元素碳和有機碳也會促成灰霾的形成。而PM2.5化學(xué)成分受地域和污染源的影響會產(chǎn)生很大差異,目前含量較多的成分是硫酸銨,硫酸,硝酸銨和碳質(zhì)氣溶膠粒子等。因此,本文主要以上述氣溶膠粒子為研究對象,分別以Mie理論和T矩陣方法研究了對應(yīng)組分的單個球形粒子和非球形粒子的散射特性,非球形微粒形狀主要包括橢球形(長短軸比為1/2,1/3,2/1),圓柱形(直徑與長度比為1/2,1/3,2/1)和切比雪夫形(其多項式n=2,形變參數(shù)為-0.1和0.1)三種。重點分析了對應(yīng)粒子的消光、散射和吸收效率因子隨尺度參數(shù)的變化,以及散射相函數(shù)隨散射角的變化特性。研究表明,硫酸銨、硫酸和硝酸銨粒子主要以散射作用為主,而碳質(zhì)氣溶膠則呈現(xiàn)很強的吸收效應(yīng),而且非球形微粒的各效率因子和球形的差異變化呈現(xiàn)先增后減,最后又增大的規(guī)律。最后通過對比不同半徑不同粒子的散射相函數(shù),表明散射相函數(shù)對粒子大小和復(fù)折射率極其敏感。該研究結(jié)果可用于大氣環(huán)境污染的光學(xué)遙感監(jiān)測。
[Abstract]:With the continuous expansion of economic scale, the pace of urbanization and the large-scale increase of the number of cars, the phenomenon of fine particle aerosol pollution caused by human production activities is increasing, and the haze weather is increasing day by day. There are four serious haze areas in China: Beijing-Tianjin-Tang region, Sichuan Basin, Pearl River Delta and Yangtze River Delta, showing the characteristics of increasing frequency and increasing haze area. In places such as Beishangguang, more than 1 / 3 days of the year are haze, and more than half of them are haze. In the face of the characteristics of small size, light mass, difficult to settle and filter, it is difficult to effectively control the atmospheric turbidity such as sand, haze and so on. Therefore, the survival and life of human beings and the climate and environment of the earth are seriously affected. Therefore, the study of haze, dust and other high concentration aerosols has become the focus of discussion at present, which has attracted great attention of the scientific community. In this paper, the research progress of scattering transport under the condition of haze and other high concentration aerosols is discussed from the following aspects: (1) the physical and optical properties of atmospheric aerosol particles; (2) the influence of particle moisture absorption on particle scattering transmission; (3) the polarized reflection characteristics of aerosols; and (4) the modeling of vector radiation transport under the background of multiple scattering between ground gases and high concentration aerosol strips. At the same time, due to the scattering and absorption of light by atmospheric aerosols, the extinction effect directly affects the visibility of the atmosphere. The related scattering theories are: Rayleigh scattering, meter scattering, T matrix method and DDA theory of non-spherical particles, and so on. When haze occurs, the concentrations of water-soluble ions NH4, NO3- and SO42- in particles (D2.5 渭 m) are much higher than those in normal weather. They are the main chemical components of PM2.5, mainly in the form of ammonium salt. These high concentrations of ammonium salt are beneficial to the formation of secondary particles, resulting in poor visibility and the formation of haze. Therefore, the particles are more acidic than non-haze during haze. In addition, elemental carbon and organic carbon also contribute to the formation of haze. However, the chemical composition of PM2.5 is very different by the influence of region and pollution sources. At present, ammonium sulfate, sulfuric acid, ammonium nitrate and carbonaceous aerosol particles are the most important components. Therefore, in this paper, the scattering characteristics of single spherical particles and non-spherical particles corresponding to the corresponding components are studied by Mie theory and T matrix method, respectively. the shape of non-spherical particles mainly includes ellipsoid shape (the ratio of length to short axis is 1: 2, 1: 3, 2: 1), cylinder (diameter to length ratio is 1: 2, 1: 3, 2: 1) and Chebyshev shape (its multinomial n 鈮，

本文編號：2506881