• 제목/요약/키워드: Atmospheric aerosols

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구름과 에어로솔의 혼재시 에어로솔의 광학특성이 상향 단파 복사에 미치는 영향 (Effects of Aerosol Optical Properties on Upward Shortwave Flux in the Presence of Aerosol and Cloud layers)

  • 이권호
    • 대한원격탐사학회지
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    • 제33권3호
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    • pp.301-311
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    • 2017
  • 에어로솔의 광학특성과 연직고도는 태양 복사의 반사와 흡수과정을 통하여 지구복사수지에 영향을 미치게 된다. 본 연구에서는 복사전달모델과 위성관측자료를 이용하여 동북아시아 지역에서 구름의 존재 시 에어로솔 층에 의한 복사특성을 분석하였다. 복사전달 모의 결과는 구름이 하부에 존재하는 경우에 에어로솔 층의 고도가 높아짐에 따라 대기 온난화 효과가 증가하였다. 이러한 관계는 에어로솔의 광 흡수성이 커질수록, 지표 반사도가 증가할수록 비례하는 경향을 나타내었다. 그리고 연구대상지역 ($20-50^{\circ}N$, $110-140^{\circ}E$)에서 주요 에어로솔 이벤트 사례에 대하여, UV Absorbing Aerosol Index (AAI) derived from Total Ozone Mapping Spectrometer (TOMS), cloud parameters derived from the Moderate Resolution Imaging Spectro-radiometer (MODIS), with Upward Shortwave Flux (USF) Clouds and the Earth's Radiant Energy System (CERES) 위성관측자료를 이용하여 광 흡수성 에어로솔에 의한 영향을 정량적으로 분석하였다. 각 사례에 대한 평균적인 복사효과는 약 6 - 26 %에 해당하는 상향 단파 복사량의 감쇄효과가 나타났다. 이러한 결과는 에어로솔에 의한 직접효과와 간접효과를 정량화 하기 위한 중요성을 설명해 준다.

Parameterization Model for Damaging Ultraviolet-B Irradiance

  • Kim, Yoo-Keun;Lee, Hwa-Woon;Moon, Yun-Seob
    • Environmental Sciences Bulletin of The Korean Environmental Sciences Society
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    • 제3권1호
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    • pp.41-56
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    • 1999
  • Since UV-B radiation measuring networks have not been established, numerical models which calculate the flux from other readily available meteorological measurements may play an important role. That is, such a problem can be solved by using parameterization models such as two stream approximation, the delta-Eddington method, doubling method, and discrete ordinate method. However, most UV-B radiative transfer models have not been validated with measurements, because such models are not intended as practical computational schemes for providing surface estimates of UV-B radiation. The main concern so far has been to demonstrate model sensitivity for cloudless skies. In particular, few have been concerned with real cloud information. Clouds and aerosols have generally been incorporated as constituents of particular atmospheric layers with specified optical depths and scattering properties. The parameterization model presented here is a combination of a detailed radiative transfer algorithm for a coludless sky radiative process and a more approximate scheme to handle cloud effects. The model input data requires a daily measurement of the total ozone amount plus a daily record of the amount and type of cloud in the atmosphere. Measurements for an examination of the models at the Department of Atmospheric Sciences, Pusan National University have been takenfrom February, 1995. These models can be used to calculate present and future fluxes where measurements have not been taken, and construct climatologies for the period before ozone depletion began.

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Affecting Factors on the Variation of Atmospheric Concentration of Polycyclic Aromatic Hydrocarbons in Central London

  • Baek, Sung-Ok;Roger Perry
    • Journal of Korean Society for Atmospheric Environment
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    • 제10권E호
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    • pp.343-356
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    • 1994
  • In this study, a statistical investigation was carried out for the evaluation of any relationship between polycyclic aromatic hydrocarbons (PAHss) associated with ambient aerosols and other air quality parameters under varying meteorological conditions. Daily measurements for PAHs and air quality/meteorological parameters were selected from a data-base constructed by a comprehensive air monitoring in London during 1985-1987. Correlation coefficients were calculated to examine any significant relationship between the PAHs and other individual variables. Statistical analysis was further Performed for the air quality/meteorological data set using a principal component analysis to derive important factors inherent in the interactions among the variables. A total of six components were identified, representing vehicle emission, photochemical activity/volatilization, space heating, atmospheric humidity, atmospheric stability, and wet deposition. It was found from a stepwise multiple regression analysis that the vehicle emission component is overall the most important factor contributing to the variability of PAHs concentrations at the monitoring site. The photochemical activity/volatilzation component appeared to be also an important factor particularly for the lower molecular weight PAHs. In general, the space heating component was found to be next important factor, while the contributions of other three components to the variance of each PAHs did not appear to be as much important as the first three components in most cases. However, a consistency for these components in their negative correlations with PAHs data was found, indicating their roles in the depletion of PAHs concentrations in the urban atmosphere.

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2013년 고산지역 연무, 황사, 연무-황사혼재 대기 에어로졸의 화학조성 특성 (Chemical Composition Characteristics of Atmospheric Aerosols in Relation to Haze, Asian Dust and Mixed Haze-Asian Dust Episodes at Gosan Site in 2013)

  • 고희정;송정민;차주완;김정은;류상범;강창희
    • 한국대기환경학회지
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    • 제32권3호
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    • pp.289-304
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    • 2016
  • The $PM_{10}$ and $PM_{2.5}$ aerosols were collected at the Gosan site of Jeju Island in 2013 and analyzed, in order to examine the variation characteristics of the chemical compositions in relation to the haze, Asian dust, and mixed haze-Asian dust episodes. Volume concentrations obtained from the Aerodynamic Particle Sizer (APS) were high in the range of $0.6{\sim}1.0{\mu}m$ particles for haze event, and in the range of $2.0{\sim}10.0{\mu}m$ particles for Asian dust event. For the haze event, nitrate concentrations increased highly as 8.8 and 25.1 times for $PM_{10}$ and $PM_{2.5}$, respectively, possibly caused by the inflow of air mass stagnated in eastern parts of China into Jeju area. For the Asian dust event, the concentrations of nss-$Ca^{2+}$, $NO_3{^-}$ and nss-$SO_4{^{2-}}$ increased 6.0, 1.5, 1.8 times for $PM_{10}$, and 2.3, 1.3, 1.6 times for $PM_{2.5}$, respectively. Meanwhile, for the mixed haze-Asian dust event, the concentrations of nss-$Ca^{2+}$ and $NO_3{^-}$ increased 13.4 and 3.2 times for $PM_{10}$, and 1.8 and 3.4 times for $PM_{2.5}$, respectively. The $NH_4NO_3$ content was higher than that of $(NH_4)_2SO_4$ during the haze event, however it was relatively low during the mixed haze-Asian dust event. The aerosols were acidified mostly by inorganic acids, and especially the nitric acid contributed highly to the acidification during both the haze and the mixed haze-Asian dust events. Meanwhile, the neutralization by ammonia was noticeably high during haze event when the stagnated air mass moved from China.

Comparison of Chemical Compositions of Size-segregated Atmospheric Aerosols between Asian Dust and Non-Asian Dust Periods at Background Area of Korea

  • Kim, Won-Hyung;Song, Jung-Min;Ko, Hee-Jung;Kim, Jin Seog;Lee, Joung Hae;Kang, Chang-Hee
    • Bulletin of the Korean Chemical Society
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    • 제33권11호
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    • pp.3651-3656
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    • 2012
  • The size-segregated atmospheric aerosols have been collected at 1100 m site of Mt. Halla in Jeju, a background area in Korea, using 8-stage cascade impact air sampler during Asian dust and non-Asian dust storm periods. Their ionic and elemental species were analyzed, in order to examine the pollution characteristics and composition change between Asian dust and non-Asian dust periods. The major ionic species such as nss-$SO_4{^{2-}}$, $NH_4{^+}$, and $K^+$ were predominantly distributed in the fine particles (below $2.1{\mu}m$ diameter), and besides the $NO_3{^-}$ was distributed more in coarse particle fraction than fine particle. On the other hand, the typical soil and marine species i.e., nss-$Ca^{2+}$, $Na^+$, $Cl^-$, and $Mg^{2+}$, were mostly existed in the coarse particles (over $2.1{\mu}m$ diameter). As well in the elemental analysis of aerosols, the major soil-originated Al, Fe, Ca, and others showed prominently high concentrations in the coarse particle fraction, whereas the anthropogenic S and Pb were relatively high in the fine particle fraction. From the comparison of aerosol compositions between Asian dust and non-Asian dust periods, the concentrations of the soil-originated species such as nss-$Ca^{2+}$, Al, Ca, Fe, Ti, Mn, Ba, Sr have increased as 2.7-4.2 times during the Asian dust periods. Meanwhile the concentrations of nss-$SO_4{^{2-}}$ and $NO_3{^-}$ have increased as 1.4 and 2.0 times, and on the contrary $NH_4{^+}$ concentrations have a little bit decreased during the Asian dust periods. Especially the concentrations of both soil-originated ionic and elemental species increased noticeably in the coarse particle mode during the dust storm periods.

나노/서브마이크론 에어로졸의 집진성능평가를 위한 이중모드 입자의 발생 (Generation of Bi-modal Particles for Performance Evaluation of Air Cleaning Devices for Submicron Aerosols)

  • 지준호;황정호
    • 한국대기환경학회:학술대회논문집
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    • 한국대기환경학회 2003년도 춘계학술대회 논문집
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    • pp.97-98
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    • 2003
  • 나노/서브마이크론 크기의 입자는 최근 유해 입자상 물질 제거 및 오염 제어나 물질 제조 등의 분야에서 관심이 높아지고 있다. 보통 환경 입자상 물질로 불리는 0.1~l $\mu\textrm{m}$ 범위의 서브마이크론 입자는 자동차, 공장, 발전소, 소각로 등의 연소 과정에서 발생되어 상당량이 대기로 배출되는데, 인체에 유입되면 호흡기 장애나 암을 유발하는 등의 나쁜 영향을 미친다. 특히, 관성력과 확산력에 의한 영향이 적고 하전 입자의 전기적인 이동도도 낮기 때문에 집진장치나 공기청정장치에서 집진효율이 가장 낮은 크기 범위이다. (중략)

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