【摘要】：氣溶膠作為大氣污染的主要成分,不僅可通過散射和吸收輻射直接影響地球大氣輻射平衡,還可通過影響云的光學(xué)特性和云的壽命間接影響地球輻射平衡。近年來,氣溶膠引起的直接輻射強(qiáng)迫成為全球研究的熱點(diǎn)。因此,準(zhǔn)確了解不同區(qū)域氣溶膠的光學(xué)特性,對(duì)于減少氣溶膠輻射強(qiáng)迫的不確定性具有重要意義。腔衰蕩光譜(Cavity Ring-Down Spectroscopy,CRDS)技術(shù)因其具有長(zhǎng)達(dá)數(shù)千米甚至數(shù)十千米的等效光程,具有超高靈敏度和低檢測(cè)限的優(yōu)點(diǎn),被認(rèn)為是進(jìn)行氣溶膠消光特性研究的有效手段。本文基于已有的CRDS技術(shù)理論的氣溶膠消光儀的技術(shù)方案,完成了可用于測(cè)量大氣氣溶膠消光系數(shù)的氣溶膠消光儀的研制及性能表征,并以昆山陽澄湖畔的實(shí)際大氣氣溶膠為研究對(duì)象,分析研究了測(cè)點(diǎn)的大氣氣溶膠的消光特性及相對(duì)濕度對(duì)消光特性的影響。本論文的主要研究成果主要集中在以下幾個(gè)方面:(1)國(guó)內(nèi)率先研制了基于CRDS技術(shù)的用于測(cè)量氣溶膠消光特性的氣溶膠消光儀,測(cè)量了實(shí)驗(yàn)室條件下產(chǎn)生的聚苯乙烯標(biāo)準(zhǔn)顆粒物的消光截面,得到了實(shí)驗(yàn)室條件下標(biāo)準(zhǔn)顆粒物的不確定性小于3%,驗(yàn)證了系統(tǒng)的可靠性。(2)對(duì)氣溶膠消光儀的性能指標(biāo)進(jìn)行了表征:儀器的背景衰蕩時(shí)間為51.26μs,消光系數(shù)的最低檢測(cè)限可達(dá)到10-7m-1量級(jí),響應(yīng)時(shí)間小于2min。氣溶膠消光儀的性能優(yōu)異,能夠?qū)崿F(xiàn)對(duì)大氣氣溶膠消光系數(shù)的高靈敏度、快速、自動(dòng)在線檢測(cè),可用于環(huán)境大氣監(jiān)測(cè)領(lǐng)域的大氣氣溶膠消光系數(shù)的實(shí)時(shí)在線監(jiān)測(cè)。(3)以昆山陽澄湖畔的實(shí)際大氣氣溶膠為研究對(duì)象,通過長(zhǎng)時(shí)間連續(xù)測(cè)量,結(jié)合氣象因子的統(tǒng)計(jì)結(jié)果,詳細(xì)分析了監(jiān)測(cè)點(diǎn)的氣溶膠消光特性及其日變化規(guī)律。觀測(cè)結(jié)果表明,氣象條件及周邊的強(qiáng)污染源對(duì)測(cè)點(diǎn)的大氣氣溶膠消光系數(shù)影響較大。(4)為了研究相對(duì)濕度對(duì)氣溶膠消光系數(shù)的影響,利用兩臺(tái)儀器同時(shí)測(cè)量了不同相對(duì)濕度下實(shí)際大氣中的氣溶膠的消光系數(shù),通過使用親水參數(shù)γ值對(duì)測(cè)點(diǎn)環(huán)境相對(duì)濕度對(duì)氣溶膠消光系數(shù)的影響進(jìn)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 緯 value.
【學(xué)位授予單位】：上海大學(xué)
【學(xué)位級(jí)別】：碩士
【學(xué)位授予年份】：2015
【分類號(hào)】：X851

【引證文獻(xiàn)】

相關(guān)會(huì)議論文 前1條

1 李學(xué)彬;徐青山;魏合理;胡歡陵;;相對(duì)濕度與能見度的相關(guān)性研究[A];中國(guó)氣象學(xué)會(huì)2007年年會(huì)氣象綜合探測(cè)技術(shù)分會(huì)場(chǎng)論文集[C];2007年

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本文編號(hào)：2278212