Remote sensing of lunar aureole with a sky camera: Adding information in the nocturnal retrieval of aerosol properties with GRASP code

REMOTE SENSING OF ENVIRONMENT

卷:196

Article

Roman, R.^1,2,3  Torres, B.^4,5  Fuertes, D.⁵  Cachorro, V. E.¹  Dubovik, O.⁴  Toledano, C.¹  Cazorla, A.^2,3  Barreto, A.^1,6,9  Bosch, J. L.^2,3,7  Lapyonok, T.⁴  Gonzalez, R.¹  Goloub, P.⁴  Perrone, M. R.⁸  Olmo, F. J.^2,3  de Frutos, A.¹  Alados-Arboledas, L.^2,3 

[1] Univ Valladolid, Atmospher Opt Grp GOA, Valladolid, Spain

[2] Univ Granada, Dept Appl Phys, E-18071 Granada, Spain

[3] Univ Granada, Autonoemous Govt Andalusia, Andalusian Inst Earth Syst Res IISTA CEAMA, Granada 18006, Spain

[4] Lille 1 Univ, CNRS, Lab Opt Atmospher, Lille, France

[5] SAS, Generalized Retrieval Atmosphere & Surface Proper, Paris, France

[6] Cimel Elect, Paris, France

[7] Univ Huelva, Dept Ingn Elect & Term, Huelva, Spain

[8] Univ Salento, Dipartimento Matemat & Fis, Lecce, Italy

[9] Meteorol State Agcy Spain AEMET, Izana Atmospher Res Ctr, Madrid, Spain

关键词: Sky camera;    Moon;    GRASP;    Aerosol;    High dynamic range;   

DOI  :  10.1016/j.rse.2017.05.013

来源: Elsevier

【 摘 要 】

The use of sky cameras for nocturnal aerosol characterization is discussed in this study. Two sky cameras are con-figured to take High Dynamic Range (HDR) images at Granada and Valladolid (Spain). Some properties of the cameras, like effective wavelengths, sky coordinates of each pixel and pixel sensitivity, are characterized. After that, normalized camera radiances at lunar almucantar points (up to 20 degrees in azimuth from the Moon) are obtained at three effective wavelengths from the HDR images. These normalized radiances are compared in different case studies to simulations fed with AERONET aerosol information, giving satisfactory results. The obtained uncertainty of normalized camera radiances is around 10% at 533 nm and 608 nm and 14% for 469 nm. Normalized camera radiances and six spectral aerosol optical depth values (obtained from lunar photometry) are used as input in GRASP code (Generalized Retrieval of Aerosol and Surface Properties) to retrieve aerosol properties for a dust episode over Valladolid. The retrieved aerosol properties (refractive indices, fraction of spherical particles and size distribution parameters) are in agreement with the nearest diurnal AERONET products. The calculated GRASP retrieval at night time shows an increase in coarse mode concentration along the night, while fine mode properties remained constant. (C) 2017 Elsevier Inc. All rights reserved.

【 授权许可】

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