光散射学报, 2017, 29 (4): 297, 网络出版: 2018-01-10  

取向数对非球形沙尘气溶胶光学特性的影响

Effect of Orientation Numbers on Optical Properties of Nonspherical Dust Aerosols
作者单位
中国气象局气溶胶与云降水重点开放实验室,南京信息工程大学大气物理学院,南京 210044
摘要
利用离散偶极子近似法研究了旋转椭球体沙尘气溶胶粒子在尺度参数变化范围为0.1~23时(波长0.55 μm对应有效半径为0.01~2 μm)的光学特性,并通过分析比较不同取向数下光学特性的差别,研究取向数对非球形沙尘粒子光学特性的影响。对单分散系,较少的取向数使旋转椭球体沙尘气溶胶粒子的各光学参量对于取向的选取敏感,但随着取向数的增多,沙尘粒子的各光学量逐步趋于一致。对多分散系,受粒子谱分布积分效果的影响,旋转椭球体沙尘气溶胶粒子对取向的敏感度,相比单分散系要稍低一些。粒子的非球形程度对获得随机取向光学特性取向数的选取也有影响,粒子非球形特征越明显,获得随机取向光学特性所需要的取向数越多。以多分散的旋转椭球体沙尘粒子为例,要获得随机取向沙尘粒子的消光效率因子、单次散射反照率和不对称因子(相对偏差在1%以内),轴半径比为16的非球形程度所需的取向数超过500,而轴半径比为2的非球形程度所需的取向数则仅超过100。
Abstract
Orientation-averaged optical properties of spheroid dust aerosol particles are carried out based on discrete dipole approximation for size parameters from 0.1 to 23(corresponding to effective radius from 0.01 to 2 μm at wavelength of 550 nm).The effects of orientation numbers on optical properties of nonspherical dust aerosols are carried out by using different orientation numbers.For monodisperse particles,optical properties of dust spheroid are sensitive to the orientation when using few orientation numbers.However,for polydisperse particles,they are less sensitive to the orientation with the effect of size distribution.For the effect of asphericity degree,the larger it is,the more orientation numbers should be utilized for orientation-averaged optical properties.Take the polydisperse spheroid dust particle as an example,to obtain the orientation-averaged extinction efficiency factor,single scattering albedo and asymmetry parameter(differences less than 1%),the orientation number should be larger than 500 for the aspect ratio of 16,but it is larger than 100 for the aspect ratio of 2.
参考文献

[1] KRIEGER U K,BRAUN C.Light-scattering intensity fluctuations in single aerosol particles during deliquescence [J].J Quant Spectrosc Radiat Transfer,2001,70: 545-554.

[2] BREWER R,BELZER W.Assessment of metal concentrations in atmospheric particles from Burnaby Lake,British Columbia,Canada [J].Atmos Environ,2001,35: 5223-5233.

[3] 饶瑞中.激光大气传输湍流与热晕综合效应[J].红外与激光工程,2006,35(2): 130-134(RAO Ruizhong.Combined effect of turbulence and thermal blooming of laser propagation in atmosphere [J].Infrared and Laser Engineering,2006,35(2): 130-134)

[4] 黄印博,王英俭.激光传输大气参量测量精度要求的数值分析[J].强激光与粒子束,2006,18(5): 720-724(HUANG Yinbo,WANG Yingjian.Effect of the measurement errors of atmospheric parameters on the laser propagation effects [J].High Power Laser and Particle Beams,2006,18(5): 720-724)

[5] HAYWOOD J M,SHINE K P.Multi-spectral calculations of the direct radiative forcing of tropospheric sulphate and soot aerosols using a column model [J].Q J Roy Meteor Soc,1997,123(543): 1907-1930.

[6] KAUFMAN Y J,KOREN I,REMER L A,et al.The effect of smoke,dust,and pollution aerosol on shallow cloud development over the Atlantic Ocean [J].PNAS,2005,102(32): 11207-11212.

[7] DUBOVIK O,SINYUK A,LAPYONOK T,et al.Application of spheroid models to account for aerosol particle nonsphericity in remote sensing of desert dust [J].J Geophys Res,2006,111: D11208.

[8] DRAINE B T,FLATAU P J.Discrete-dipole approximation for scattering calculations [J].J Opt Soc Am,1994,11: 1491-1499.

[9] DRAINE B T,FLATAU P J.Discrete dipole approximation for periodic targets: I.Theory and tests [J].J Opt Soc Am,2008,25: 2693-2703.

[10] DRAINE B T,FLATAU P J.Fast near-field calculations in the discrete dipole approximation for regular rectilinear grids [J].Opt Express,2012,20(2): 1247-1252.

[11] DRAINE B T,FLATAU P J.User guide for the discrete dipole approximation code DDSCAT 7.2 [EB/OL].arXiv,http: //arXiv.org/abs/1202.3424,2012.

[12] 张小林,黄印博,饶瑞中.复杂成分内混合体光散射等效性分析的判据选取[J].光散射学报,2012,24(2): 125-132(ZHANG Xiaolin,HUANG Yinbo,RAO Ruizhong.Parameter selection of light-scattering equivalence for complex internal-mixed particles [J].The Journal of Light Scattering,2012,24(2): 125-132)

[13] 张小林,毛毛,银燕.随机取向非球形沙尘气溶胶粒子的光学特性[J].光散射学报,2017,29(1): 16-22(ZHANG Xiaolin,MAO Mao,YIN Yan.Orientation-averaged optical properties of nonspherical dust aerosols [J].The Journal of Light Scattering,2017,29(1): 16-22)

[14] FENN R W,CLOUGH S A,GALLERY W O,et al.Optical and infrared properties of the atmosphere,Chapter 18 in Handbook of Geophysics and the Space Environment [R].Jursa A S,Air Force Geophysics Laboratory,Hanscom AFB,MA,1985.

[15] MANN G W,CARSLAW K S,SPRACKLEN D V,et al.Description and evaluation of GLOMAP-mode: a modal global aerosol microphysics model for the UKCA composition-climate model [J].Geoscientific Model Development,2010,3: 519-551.

张小林, 毛毛, 银燕. 取向数对非球形沙尘气溶胶光学特性的影响[J]. 光散射学报, 2017, 29(4): 297. ZHANG Xiaolin, MAO Mao, YIN Yan. Effect of Orientation Numbers on Optical Properties of Nonspherical Dust Aerosols[J]. The Journal of Light Scattering, 2017, 29(4): 297.

关于本站 Cookie 的使用提示

中国光学期刊网使用基于 cookie 的技术来更好地为您提供各项服务,点击此处了解我们的隐私策略。 如您需继续使用本网站,请您授权我们使用本地 cookie 来保存部分信息。
全站搜索
您最值得信赖的光电行业旗舰网络服务平台!