• Title/Summary/Keyword: linear particle depolarization ratio

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Aerosol Optical Properties Retrieval and Separation of Asian Dust using AERONET Sun/Sky Radiometer Measurement at the Asian Dust Source Region (황사 발원지에서 선포토미터를 활용한 에어로졸의 광학적 특성 산출과 미세먼지속 황사구분)

  • Shin, Dongho;Noh, Youngmin
    • Korean Journal of Remote Sensing
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    • v.32 no.3
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    • pp.245-251
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    • 2016
  • We present linear particle depolarization ratio at 440, 675, 870, and 1020 nm retrieved from measurements with an AERONET sun/sky radiometer at the source region of Asian dust, Dunhuang. The linear particle depolarization ratios are retrieved at the two receptor sites (Gosan and Osaka). The highest linear particle depolarization ratio of 0.34 at 1020 nm is retrieved from nearly pure Asian dust. The linear particle depolarization ratio decreased as the volume concentration of fine-mode particle increased. We can confirm that the ratio of Asian dust is changed by the value of the linear particle depolarization ratio retrieved by AERONET data.

Retrieval of Depolarization ratio using Sunphotometer data and Comparison with LIDAR Depolarization ratio (선포토미터 데이터를 이용한 편광소멸도 산출과 라이다 편광소멸도와의 비교)

  • Kim, Kwanchul;Choi, Sungchul;Noh, Youngmin
    • Korean Journal of Remote Sensing
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    • v.32 no.2
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    • pp.97-104
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    • 2016
  • We present linear particle depolarization ratio at 440, 675, 870, and 1020 nm retrieved from measurements with an AERONET sun/sky radiometer at Osaka, Japan. The retrieved data were compared with lidar derived linear particle depolarization ratio at 532 nm at the same site. We find good agreement between linear particle depolarization ratios derived with Sun photometer and measured by lidar except for those at 440 nm. The coefficients of determination between lidar derived data and sun/sky radiometer derived data were 0.28, 0.81, 0.88, and 0.89 at 440, 675, 870, and 1020 nm, respectively. We find that the linear particle depolarization ratio derived with sun/sky radiometer varies by the mixing between Asian dust and pollution particles. As the mixing ratio of Asian dust and pollution particles is increased, the linear particle depolarization ratio values are lower than the values of pure Asian dust. It was confirmed by the value of single-scattering albedo and particle size distribution.

Depolarization Ratio Retrievals Using AERONET Sun Photometer Data

  • Lee, Kyung-Hwa;Muller, Detlef;Noh, Young-Min;Shin, Sung-Kyun;Shin, Dong-Ho
    • Journal of the Optical Society of Korea
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    • v.14 no.3
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    • pp.178-184
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    • 2010
  • We present linear particle depolarization ratios (LPDRs) retrieved from measurements with an AERONET Sun photometer at the Gwangju Institute of Science and Technology (GIST), Korea ($35.10^{/circ}N$, $126.53^{\circ}E$) between 19 October and 3 November 2009. The Sun photometer data were classified into three categories according to ${\AA}$ngstr$\ddot{o}$ exponent and size distribution: 1) pure Asian dust (19 October 2009), 2) Asian dust mixed with urban pollution observed in the period from 20-26 October 2009, and 3) clean conditions (3 November). We show that the LPDRs can be used to distinguish among Asian dust, mixed aerosol, and non-Asian dust in the atmosphere. The mean LPDR of the pure Asian dust case is 23 %. Mean LPDRs are 13 % for the mixed case. The lowest mean LPDR is 6 % in the clean case. We compare our results to vertically resolved LPDRs (at 532 nm) measured by a Raman LIDAR system at the same site. In most cases, we find good agreement between LPDRs derived with Sun photometer and measured by LIDAR.