气候变化领域集成服务门户(CCPortal): Reflective properties of melt ponds on sea ice

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DOI	10.5194/tc-12-1921-2018
	Reflective properties of melt ponds on sea ice
	Malinka A.; Zege E.; Istomina L.; Heygster G.; Spreen G.; Perovich D.; Polashenski C.
发表日期	2018
ISSN	19940416
卷号	12 期号:6
英文摘要	Melt ponds occupy a large part of the Arctic sea ice in summer and strongly affect the radiative budget of the atmosphere-ice-ocean system. In this study, the melt pond reflectance is considered in the framework of radiative transfer theory. The melt pond is modeled as a plane-parallel layer of pure water upon a layer of sea ice (the pond bottom). We consider pond reflection as comprising Fresnel reflection by the water surface and multiple reflections between the pond surface and its bottom, which is assumed to be Lambertian. In order to give a description of how to find the pond bottom albedo, we investigate the inherent optical properties of sea ice. Using the Wentzel-Kramers-Brillouin approximation approach to light scattering by non-spherical particles (brine inclusions) and Mie solution for spherical particles (air bubbles), we conclude that the transport scattering coefficient in sea ice is a spectrally independent value. Then, within the two-stream approximation of the radiative transfer theory, we show that the under-pond ice spectral albedo is determined by two independent scalar values: the transport scattering coefficient and ice layer thickness. Given the pond depth and bottom albedo values, the bidirectional reflectance factor (BRF) and albedo of a pond can be calculated with analytical formulas. Thus, the main reflective properties of the melt pond, including their spectral dependence, are determined by only three independent parameters: pond depth z, ice layer thickness H, and transport scattering coefficient of ice σt. The effects of the incident conditions and the atmosphere state are examined. It is clearly shown that atmospheric correction is necessary even for in situ measurements. The atmospheric correction procedure has been used in the model verification. The optical model developed is verified with data from in situ measurements made during three field campaigns performed on landfast and pack ice in the Arctic. The measured pond albedo spectra were fitted with the modeled spectra by varying the pond parameters (z, H, and σt). The coincidence of the measured and fitted spectra demonstrates good performance of the model: it is able to reproduce the albedo spectrum in the visible range with RMSD that does not exceed 1.5% for a wide variety of melt pond types observed in the Arctic. © Author(s) 2018.
学科领域	albedo; atmosphere-ocean coupling; atmospheric correction; bidirectional reflectance; ice thickness; pack ice; radiative transfer; sea ice; Arctic Ocean; Lambertia
语种	英语
scopus关键词	albedo; atmosphere-ocean coupling; atmospheric correction; bidirectional reflectance; ice thickness; pack ice; radiative transfer; sea ice; Arctic Ocean; Lambertia
来源期刊	Cryosphere
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/119135
作者单位	Institute of Physics, National Academy of Sciences of Belarus, pr. Nezavisimosti 68-2, Minsk, 220072, Belarus; Institute of Environmental Physics, University of Bremen, Otto-Hahn-Allee 1, Bremen, 28359, Germany; Thayer School of Engineering, Dartmouth College, Hanover, NH, United States; Cold Regions Research and Engineering Laboratory, Engineer Research and Development Center, Hanover, NH, United States
推荐引用方式 GB/T 7714	Malinka A.,Zege E.,Istomina L.,et al. Reflective properties of melt ponds on sea ice[J],2018,12(6).
APA	Malinka A..,Zege E..,Istomina L..,Heygster G..,Spreen G..,...&Polashenski C..(2018).Reflective properties of melt ponds on sea ice.Cryosphere,12(6).
MLA	Malinka A.,et al."Reflective properties of melt ponds on sea ice".Cryosphere 12.6(2018).