气候变化领域集成服务门户(CCPortal): Refinement of the ice absorption spectrum in the visible using radiance profile measurements in Antarctic snow

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DOI	10.5194/tc-10-2655-2016
	Refinement of the ice absorption spectrum in the visible using radiance profile measurements in Antarctic snow
	Picard G.; Libois Q.; Arnaud L.
发表日期	2016
ISSN	19940416
卷号	10 期号:6
英文摘要	Ice is a highly transparent material in the visible. According to the most widely used database (IA2008; Warren and Brandt, 2008), the ice absorption coefficient reaches values lower than 10-3 m-1 around 400 nm. These values were obtained from a vertical profile of spectral radiance measured in a single snow layer at Dome C in Antarctica.We reproduced this experiment using an optical fiber inserted in the snow to record 56 profiles from which 70 homogeneous layers were identified. Applying the same estimation method on every layer yields 70 ice absorption spectra. They present a significant variability but absorption coefficients are overall larger than IA2008 by 1 order of magnitude at 400-450 nm. We devised another estimation method based on Bayesian inference that treats all the profiles simultaneously. It reduces the statistical variability and confirms the higher absorption, around 2×10-2 m-1 near the minimum at 440 nm. We explore potential instrumental artifacts by developing a 3-D radiative transfer model able to explicitly account for the presence of the fiber in the snow. The simulation shows that the radiance profile is indeed perturbed by the fiber intrusion, but the error on the ice absorption estimate is not larger than a factor of 2. This is insufficient to explain the difference between our new estimate and IA2008. The same conclusion applies regarding the plausible contamination by black carbon or dust, concentrations reported in the literature are insufficient. Considering the large number of profiles acquired for this study and other estimates from the Antarctic Muon and Neutrino Detector Array (AMANDA), we nevertheless estimate that ice absorption values around 10-2 m-1 at the minimum are more likely than under 10-3 m-1. A new estimate in the range 400-600 nm is provided for future modeling of snow, cloud, and sea-ice optical properties. Most importantly, we recommend that modeling studies take into account the large uncertainty of the ice absorption coefficient in the visible and that future estimations of the ice absorption coefficient should also thoroughly account for the impact of the measurement method. © Author(s) 2016.
学科领域	absorption coefficient; absorption spectrum; array; black carbon; cloud; database; estimation method; ice; measurement method; optical property; radiance; radiative transfer; sea ice; snow; three-dimensional modeling; visible spectrum; Antarctica; Dome Concordia; East Antarctica
语种	英语
scopus关键词	absorption coefficient; absorption spectrum; array; black carbon; cloud; database; estimation method; ice; measurement method; optical property; radiance; radiative transfer; sea ice; snow; three-dimensional modeling; visible spectrum; Antarctica; Dome Concordia; East Antarctica
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/119550
作者单位	UGA/CNRS, Laboratoire de Glaciologie et Géophysique de l'Environnement (LGGE), UMR5183, Grenoble, 38041, France; ACE CRC, University of Tasmania, Private Bag 80, Hobart, TAS 7001, Australia; Department of Earth and Atmospheric Sciences, Université du Québec À Montréal (UQAM), Montréal, Canada
推荐引用方式 GB/T 7714	Picard G.,Libois Q.,Arnaud L.. Refinement of the ice absorption spectrum in the visible using radiance profile measurements in Antarctic snow[J],2016,10(6).
APA	Picard G.,Libois Q.,&Arnaud L..(2016).Refinement of the ice absorption spectrum in the visible using radiance profile measurements in Antarctic snow.Cryosphere,10(6).
MLA	Picard G.,et al."Refinement of the ice absorption spectrum in the visible using radiance profile measurements in Antarctic snow".Cryosphere 10.6(2016).