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本研究通过对金星大气中云和霾进行详细的分层建模和辐射传输模拟，并结合金星快车SPICAV IR仪器的近红外观测数据，探讨了云和霾粒子的微物理性质及其对金星（盘）线偏振度的影响。结果表明，不同模式粒子的单次散射和线偏振特性在相位角和波长上呈现显著变化，上层霾和云粒子（Mode1和Mode 2）的微物理性质对金星的线偏振度影响尤为显著。Mode 1粒子的柱密度减小或模态半径增大均会使线偏振峰值增加，而线偏振度对Mode 2粒子柱密度的变化与Mode 1趋势相反。复折射率实部的变化对偏振特性影响显著，而虚部影响较小。此外，线偏振度在金星盘上随波长、相位角及位置（中心与边缘）变化明显，盘积分的线偏振特性对粒子微物理性质和大气水平不均匀性（如云量分布）高度敏感，且光环现象清晰可见。多层模型的模拟结果与SPICAV IR中低纬数据拟合较好，这种详细分层建模为揭示金星大气中云和霾的微物理特性及其辐射传输特性提供了重要依据。This study uses the PyMieDAP radiative transfer model to simulate the radiative properties of Venus' clouds and haze, investigating how their microphysical characteristics affect linear polarization, in comparison with near-infrared polarization data from the SPICAV IR instrument aboard Venus Express. The results show that single-scattered fluxes of the four particle modes decrease in the phase angle range of 0° to 120°, but increase near 160°. Mode 1 particles (upper haze) exhibit Rayleigh scattering characteristics, with polarization transitioning from positive to negative as the wavelength increases. Mode 2 and Mode 2' particles display two positive polarization peaks near 15° and 160°, with polarization reversing in the near-infrared. Mode 3 particles show oscillations in polarization near 105°, flipping from positive to negative between 155° and 165°. The primary polarization peak occurs near 15°, corresponding to the main rainbow, while a secondary peak between 150° and 160° is attributed to anomalous diffraction.
The microphysical properties of upper clouds and haze (Mode 1 and Mode 2) significantly affect Venus' linear polarization, while those of lower clouds (Mode 2' and Mode 3) have a minimal impact. A reduction in Mode 1 column density increases the polarization peak at the main rainbow, while an increase in Mode 2 column density has the opposite effect. Changes in modal radius enhance polarization peaks for Mode 1 and Mode 2, while increasing geometric standard deviation reduces polarization peaks and shifts their phase angles. The real part of the complex refractive index has a greater impact on polarization than the imaginary part. Simulations using the multilayer model show better agreement with SPICAV IR data, consistent with the larger particle sizes in Venus' haze.The integrated linear polarization across the Venus disk varies with wavelength and phase angle, with higher polarization at the disk's edge. Variations in cloud coverage also influence polarization, with less cloudy regions exhibiting higher values. Future studies should explore the effects of cloud and haze parameters on line polarization, as inversion of these parameters is beyond the scope of this work.-
Keywords:
- Venusian clouds and haze /
- linear polarization /
- sensitivity analysis /
- microphysical properties
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[1] Lyot B 1929(Tessier)
[2] Coffeen D L 1969 Astronomical Journal 74 446
[3] Dyck H, Forbes F, Shawl S 1971 Astronomical Journal 901-915 76 901
[4] Hansen J E, Hovenier J 1974 J. atmos. Sci 31 1137
[5] Esposito L, Knollenberg R, Marov M, Toon O, Turco R 1983 Venus 484
[6] Pollack J B, Dalton J B, Grinspoon D, Wattson R B, Freedman R, Crisp D, Allen D A, Bezard B, DeBergh C, Giver L P 1993 Icarus 103 1
[7] Rossi L, Marcq E, Montmessin F, Fedorova A, Stam D, Bertaux J-L, Korablev O 2015 Planetary and Space Science 113 159
[8] Li Y Q, Sun X B, Huang H L, Liu X, Ti R F, Zheng X B, Fan Y Z, Yu H X, Wei Y C, Wang Y X, Wang Y Y 2024 Journal of Infrared and Millimeter Waves 43 657(in Chinese) [李宜奇, 孙晓兵, 黄红莲, 刘晓, 提汝芳, 郑小兵, 樊依哲, 余海啸, 韦祎晨, 王宇轩王宇瑶2024 红外与毫米波学报43 657]
[9] Hansen J E, Travis L D 1974 Space science reviews 16 527
[10] Stam D 2008 Astronomy & Astrophysics 482 989
[11] Stam D, Hovenier J, Waters L 2004 Astronomy & Astrophysics 428 663
[12] Bertaux J-L, Nevejans D, Korablev O, Villard E, Quémerais E, Neefs E, Montmessin F, Leblanc F, Dubois J-P, Dimarellis E 2007 Planetary and Space Science 55 1673
[13] Svedhem H, Titov D, McCoy D, Lebreton J-P, Barabash S, Bertaux J-L, Drossart P, Formisano V, Häusler B, Korablev O 2007 Planetary and Space Science 55 1636
[14] Korablev O, Fedorova A, Bertaux J-L, Stepanov A, Kiselev A, Kalinnikov Y K, Titov A Y, Montmessin F, Dubois J-P, Villard E 2012 Planetary and Space Science 65 38
[15] Rossi L, Berzosa-Molina J, Stam D M 2018 Astronomy & Astrophysics 616 A147
[16] de Haan J F, Bosma P, Hovenier J 1987 Astronomy & Astrophysics 183 371
[17] Peterson P 2009 International Journal of Computational Science and Engineering 4 296
[18] Zasova L, Moroz V, Linkin V, Khatuntsev I, Maiorov B 2006 Cosmic Research 44 364
[19] Braak C, De Haan J, Hovenier J, Travis L 2002 Journal of Geophysical Research: Planets 107 5
[20] Knibbe W J J, de Haan J F, Hovenier J W, Travis L D 1998 Journal of Geophysical Research: Planets 103 8557
[21] Palmer K F, Williams D 1975 Applied Optics 14 208
[22] Haus R, Kappel D, Arnold G 2015 Planetary and Space Science 117 262
[23] Mie G 1908 Annalen der physik 330 377
[24] Hulst H C, van de Hulst H C 1981Light scattering by small particles (Courier Corporation)
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