The two-stream δ-Eddington approximation to simulate the far infrared Earth spectrum for the simultaneous atmospheric and cloud retrieval

被引:13
作者
Di Natale, Gianluca [1 ]
Palchetti, Luca [1 ]
Bianchini, Giovanni [1 ]
Ridolfi, Marco [1 ,2 ]
机构
[1] INO CNR, Via Madonna Piano 10, Florence, Italy
[2] Univ Bologna, Dipartimento Fis & Astron, Via Irnerio 46, Bologna, Italy
关键词
Two-streams delta-Eddington approximation; Cloud retrieval; Cirrus clouds; Far-infrared spectral radiance; RADIATIVE PROPERTIES; MULTIPLE-SCATTERING; CIRRUS CLOUDS; WATER-VAPOR; ALGORITHM; SIGNATURES; IMPACT; MODEL;
D O I
10.1016/j.jqsrt.2020.106927
中图分类号
O43 [光学];
学科分类号
070207 ; 0803 ;
摘要
Far- to mid- infrared spectral radiances measured either from high altitude platforms or from ground can be processed to retrieve atmospheric vertical profiles and cloud parameters, variables particularly relevant in climate change studies. The retrieval requires a forward model with the capability of simulating the multiple scattering from cloud particles. The Discrete Ordinate Radiative Transfer (DISORT) offers this possibility, however, accurate simulations can be obtained only with a huge computational load. We developed a forward / retrieval model based on the two-streams delta-Eddington approximation, allowing much faster computations, while retaining good accuracy. The code, named SACR (Simultaneous Atmospheric and Clouds Retrieval), allows to retrieve simultaneously temperature and gas profiles, cloud micro-physical and geometrical parameters and surface temperature from vertical sounding observations. We illustrate the equations implemented in the SACR code, prove the self-consistency of the inversion and assess its forward model accuracy with a focus on the range from 200 to 1000 cm(-1). The assessment is made by comparing the simulated spectral radiances to those computed by LBLDIS, a very accurate model integrating LBLRTM (Line By Line Radiative Transfer Model) and DISORT. For cloud particle sizes between 20 and 100 pm and optical depths between 0.1 and 10, our model shows biases smaller than 0.4 mW/(m(2) sr cm(-1)) in upwelling radiance simulations, and biases smaller than 0.3 mW/(m(2) sr cm(-1)) in downwelling radiance simulations. Depending on the spectral grid and on the number of atmospheric layers used, the SACR code is from 5 to 8 times faster than LBLDIS. (C) 2020 Elsevier Ltd. All rights reserved.
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页数:11
相关论文
共 65 条
[41]   The Modified Gamma Size Distribution Applied to Inhomogeneous and Nonspherical Particles: Key Relationships and Conversions [J].
Petty, Grant W. ;
Huang, Wei .
JOURNAL OF THE ATMOSPHERIC SCIENCES, 2011, 68 (07) :1460-1473
[42]  
Rathke C, 2000, J ATMOS OCEAN TECH, V17, P1509, DOI 10.1175/1520-0426(2000)017<1509:ROCMPF>2.0.CO
[43]  
2
[44]   Detection of organic compound signatures in infra-red, limb emission spectra observed by the MIPAS-B2 balloon instrument [J].
Remedios, J. J. ;
Allen, G. ;
Waterfall, A. M. ;
Oelhaf, H. ;
Kleinert, A. ;
Moore, D. P. .
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2007, 7 (06) :1599-1613
[45]  
Rodgers C.D., 2004, Inverse methods for atmospheric sounding: theory and practice, DOI DOI 10.1142/3171
[46]   A variational approach for retrieving ice cloud properties from infrared measurements: application in the context of two IIR validation campaigns [J].
Sourdeval, O. ;
C-Labonnote, L. ;
Brogniez, G. ;
Jourdan, O. ;
Pelon, J. ;
Garnier, A. .
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2013, 13 (16) :8229-8244
[47]   Fast cloud parameter retrievals of MIPAS/Envisat [J].
Spang, R. ;
Arndt, K. ;
Dudhia, A. ;
Hoepfner, M. ;
Hoffmann, L. ;
Hurley, J. ;
Grainger, R. G. ;
Griessbach, S. ;
Poulsen, C. ;
Remedios, J. J. ;
Riese, M. ;
Sembhi, H. ;
Siddans, R. ;
Waterfall, A. ;
Zehner, C. .
ATMOSPHERIC CHEMISTRY AND PHYSICS, 2012, 12 (15) :7135-7164
[48]   NUMERICALLY STABLE ALGORITHM FOR DISCRETE-ORDINATE-METHOD RADIATIVE-TRANSFER IN MULTIPLE-SCATTERING AND EMITTING LAYERED MEDIA [J].
STAMNES, K ;
TSAY, SC ;
WISCOMBE, W ;
JAYAWEERA, K .
APPLIED OPTICS, 1988, 27 (12) :2502-2509
[49]  
Stamnes K., 2000, GEN PURPOSE FORTRAN
[50]   The cloudsat mission and the a-train - A new dimension of space-based observations of clouds and precipitation [J].
Stephens, GL ;
Vane, DG ;
Boain, RJ ;
Mace, GG ;
Sassen, K ;
Wang, ZE ;
Illingworth, AJ ;
O'Connor, EJ ;
Rossow, WB ;
Durden, SL ;
Miller, SD ;
Austin, RT ;
Benedetti, A ;
Mitrescu, C .
BULLETIN OF THE AMERICAN METEOROLOGICAL SOCIETY, 2002, 83 (12) :1771-1790