• Title/Summary/Keyword: Sunphotometer

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Visibility Estimated from the Multi-wavelength Sunphotometer during the Winter 2011 Intensive Observation Period at Seoul, Korea (2011년 겨울철 서울시 대기 집중 관측 기간 동안 다파장 복사계로 분석된 에어러솔 연직분포와 시정 거리)

  • Lee, Kwon-Ho;Kim, Kyung-Won;Kim, Gwanchul;Jung, Kweon;Lee, Soon-Hee
    • Journal of Korean Society for Atmospheric Environment
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    • v.29 no.5
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    • pp.682-691
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    • 2013
  • The aerosol extinction vertical profile and surface visibility have been derived from the Microtops-II sunphotometer observation during the winter 2011 intensive observation period (IOP) at Seoul, Korea. Using models of degradation of aerosol optical thickness (AOT) and aerosol scale height, we have performed extinction-visibility modulation to determine the height dependent aerosol extinction and visibility. It is shown that the aerosol loading is relatively low during IOP (mean $AOT_{550}=0.22{\pm}0.08$, ${\AA}$ngstr$\ddot{o}$m exponent=$1.14{\pm}0.26$). Modeled extinction by use of Microtops II sunphotometer data shows good agreement with measurements by the Multi-wavelenth Polarization Lidar (MPoLAR), and the derived surface visibility are consistent with data from the transmissometer. These results emphasize the use of a vertically resolved extinction from AOT to predict visibility conditions at ground level.

Aerosol Optical Properties retrieved Sunphotometer Measurements at Kosan during ACE-Asia IOP (ACE-Asia 기간동안 제주 고산의 Sunphotometer 관측을 통한 에어로졸 광학특성 분석)

  • 민희경;김지영;최병철;이상삼;오성남
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2001.11a
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    • pp.277-278
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    • 2001
  • 대기 중 에어로졸은 지구표면에 도달하는 태양복사에너지를 흡수 또는 산란시키는 직접 효과 및 대기물리작용에 의한 구름의 형성 및 구름 수명에 영향을 미치는 간접 효과를 통해 지구복사 평형에 불균형을 초래함으로써 전지구적인 기후변화에 영향을 미친다. 이들 에어로졸은 온실기체와는 달리 -0.4~-3.0 W/$m^2$의 지구 평균 복사강제력을 나타내면서(IPCC, 1995) 대기 중에 냉각 효과(white- house effort)를 일으킨다(Schwartz, 1996). (중략)

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Aerosol Optical Thickness of the Yellow Sand from Direct Solar Radiation at Anmyon Island during the Spring of 1998 (안면도에서1998년 봄철에 관측된 황사의 광학적 특징)

  • Shin, Do-Shick;Kim, San;Kim, Jeong-Sik;Cha, Ju-Wan
    • Journal of Korean Society for Atmospheric Environment
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    • v.15 no.6
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    • pp.739-746
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    • 1999
  • The spectral aerosol optical thickness of vertical air columns were measured by a ground-based multi-channel sunphotometer at the BAPMoN station(36$^{\circ}$31'N, 126$^{\circ}$19'E) in Anmyon Island, Korea, from 1 March 1998 to 31 May 1998. We used the data of three yellow sand and two clear sky days in order to analyze the temporal variations in aerosol optical thickness at the station. The basic aerosol optical thickness generally represented smaller than 0.3 in a clear sky and the range 0.5 to 1.1 in yellow sand. Especially the aerosol optical thickness represented larger than 0.9 in a heavy yellow sand. It was found that the aerosol optical thickness of yellow sand was highly increased in comparison with the case of a clear sky andparticles larger than 0.5$mu extrm{m}$ were also increased in the spectral distribution of aerosol volume during yellow sand. Consequently the spectral variations in tropospheric aerosol caused by yellow sand were determined by the number concentration of particles larger than 0.5${\mu}{\textrm}{m}$ and the magnitude of yellow sand.

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Estimation of surface-level PM2.5 concentration based on MODIS aerosol optical depth over Jeju, Korea (MODIS 자료의 에어로졸의 광학적 두께를 이용한 제주지역의 지표면 PM2.5 농도 추정)

  • Kim, Kwanchul;Lee, Dasom;Lee, Kwang-yul;Lee, Kwonho;Noh, Youngmin
    • Korean Journal of Remote Sensing
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    • v.32 no.5
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    • pp.413-421
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    • 2016
  • In this study, correlations between Moderate Resolution Imaging Spectroradiometer (MODIS) derived Aerosol Optical Depth (AOD) values and surface-level $PM_{2.5}$ concentrations at Gosan, Korea have been investigated. For this purpose, data from various instruments, such as satellite, sunphotometer, Optical Particle Counter (OPC), and Micro Pulse Lidar (MPL) on 14-24 October 2009 were used. Direct comparison between sunphotometer measured AOD and surface-level $PM_{2.5}$ concentrations showed a $R^2=0.48$. Since the AERONET L2.0 data has significant number of observations with high AOD values paired to low surface-level $PM_{2.5}$ values, which were believed to be the effect of thin cloud or Asian dust. Correlations between MODIS AOD and $PM_{2.5}$ concentration were increased by screening thin clouds and Asian dust cases by use of aerosol profile data on Micro-Pulse Lidar Network (MPLNet) as $R^2$ > 0.60. Our study clearly demonstrates that satellite derived AOD is a good surrogate for monitoring atmospheric PM concentration.

Study on the vertical profiles and optical property of aerosol measured at Gosan, Jeju (제주 고산에서 관측된 에어러솔의 수직분포 및 광학적 특성에 대한 연구)

  • 이병일;원재광;윤순창;봉선화;신승숙
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.05b
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    • pp.81-82
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    • 2003
  • 제주도 서단의 고산 상층기상대는 한반도와 중국대륙, 그리고 대양으로부터의 물질이동의 중간 경로에 위치한 지리적인 요인에 의하여, 동아시아 지역의 대기오염물질의 특성을 파악하기 유리한 장소라 할 수 있다. 2001년부터 계절에 따라 이 지역에서 Micro Pulse Lidar(MPL)를 이용한 에어러솔 관측이 수행되었고, sunphotometer 관측도 병행되어 에어러솔의 공간분포 및 광학적 특성을 파악할 수 있었다. (중략)

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Comparison Study of Numerical Simulations Associated with Emission Conditions during Asian Dust Events

  • Kim, Yoo-Keun;Song, Sang-Keun;Jeong, Ju-Hee
    • Proceedings of the Korea Air Pollution Research Association Conference
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    • 2003.11a
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    • pp.518-519
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    • 2003
  • Many studies of Asian dust have been undertaken to investigate dust sources, their transport and deposition mechanisms, their optical and chemical properties, and their physical characteristics. These studies have used meteorological parameters, optical thickness, and mineral compositions derived from satellite images, lidar, sunphotometer, and other ground-based instruments in East Asia (Chun et al., 2001; Murayama et al., 2001). (omitted)

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A Study on the Characteristic and AOD Variation according to Aerosol Types Using AERONET Sunphotometer Data in Korea (AERONET 선포토미터 자료를 이용한 국내 에어로졸 유형별 특성과 광학적 두께 변화 연구)

  • Joo, Sohee;Dehkhoda, Naghmeh;Noh, Youngmin
    • Korean Journal of Remote Sensing
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    • v.36 no.2_1
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    • pp.93-101
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    • 2020
  • For the first time in Korea, aerosol type was separated as PD (Pure dust), DDM (Dust Dominant Mixed), PDM (Pollution Dominant Mixed), NA (Non-Absorbing), WA (Weakly Absorbing), MA (Moderately Absorbing), and SA (Strongly Absorbing) using depolarization ratio and single-scattering albedo based on AERONET sunphotometer data. Then, seasonal and annual occurrence frequency and AOD variation are analyzed. The proportion of pollution aerosols (NA, WA, MA, SA combined) was 58.9, 46.2, 59.5, and 67.1% at Anmyeon, Gosan, Gwangju, Seoul, respectively, with Seoul being the highest and the lowest at Gosan. Annual rate changestended to increase NA and decrease PD and DDM. The AOD by type showed the highest NA at all sites. In addition, the ratio of NA and AOD continued to increase.

A case study of aerosol features of Asian dust, fog, clear sky, and cloud at Anmyeon Island in April 2006 (2006년 4월 안면도에서 발생한 황사, 안개, 청명, 구름 사례에 대한 에어러솔 특성 분석)

  • Goo, Tae-Young;Hong, Gi-Man;Kim, Sang-Beak;Gong, Jong-Ung;Kim, Myoung-Soo
    • Atmosphere
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    • v.18 no.2
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    • pp.97-109
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    • 2008
  • The aerosol characteristics in terms of 4 different cases (Asian dust, fog, clear sky and cloud) which had happened at Anmyeon Island in April 2006 were studied using various measurements such as the Micro Pulse Lidar (MPL), sunphotometer, $\beta$-ray $PM_{10}$ Analyzer, anemoscope and anemometer. In addition, synoptic charts, back trajectory analyses and satellite images were also used to help characterize the aerosol events. The aerosol optical properties were featured by the Aerosol Optical Depth (AOD) and ${\AA}ngstr\ddot{o}m$ exponent which were estimated by the sunphotometer. When Anmyeon Island was dominated by the Asian dust, the AOD was sharply increased as seven times as a yearly average of it (0.35). As compared with a yearly average of the ${\AA}ngstr\ddot{o}m$ exponent of 0.97, the ${\AA}ngstr\ddot{o}m$ exponent of a dust day was significantly low (0.099). In addition, $PM_{10}$ mass concentration showed an extremely high record. The maximum concentration reached $1790.5{\mu}gm^{-3}$ on 8 April 2006. The maximum mass concentration was shown with delay when the wind speed of $0ms^{-1}$ was observed. It was also found that a satellite image of the MODIS-RGB had a good agreement with the results of those measurements. It was shown that the MPL was able to describe effectively the vertical distribution of aerosol for all the cases. In particular, the MPL evidently captured the aerosol layer before the cloud observation. The aerosol layer was similarly described by the AOD. On a clear sky day, the AOD had not only a very low value (0.054) but also a feature of homogeneity.