气候变化领域集成服务门户(CCPortal): Methanesulfonic acid (MSA) migration in polar ice: Data synthesis and theory

CCPortal

DOI	10.5194/tc-11-2439-2017
	Methanesulfonic acid (MSA) migration in polar ice: Data synthesis and theory
	Osman M.; Das S.B.; Marchal O.; Evans M.J.
发表日期	2017
ISSN	19940416
卷号	11 期号:6
英文摘要	Methanesulfonic acid (MSA; CH3SO3H) in polar ice is a unique proxy of marine primary productivity, synoptic atmospheric transport, and regional sea-ice behavior. However, MSA can be mobile within the firn and ice matrix, a post-depositional process that is well known but poorly understood and documented, leading to uncertainties in the integrity of the MSA paleoclimatic signal. Here, we use a compilation of 22 ice core MSA records from Greenland and Antarctica and a model of soluble impurity transport in order to comprehensively investigate the vertical migration of MSA from summer layers, where MSA is originally deposited, to adjacent winter layers in polar ice. We find that the shallowest depth of MSA migration in our compilation varies over a wide range (∼2 to 400 m) and is positively correlated with snow accumulation rate and negatively correlated with ice concentration of NaC (typically the most abundant marine cation). Although the considered soluble impurity transport model provides a useful mechanistic framework for studying MSA migration, it remains limited by inadequate constraints on key physicochemical parameters-most notably, the diffusion coefficient of MSA in cold ice (DMS). We derive a simplified version of the model, which includes DMS as the sole parameter, in order to illuminate aspects of the migration process. Using this model, we show that the progressive phase alignment of MSA and NaC concentration peaks observed along a high-resolution West Antarctic core is most consistent with 10-12 m2 s-1 DMS 10-11 m-2 s-1, which is 1 order of magnitude greater than the DMS values previously estimated from laboratory studies. More generally, our data synthesis and model results suggest that (i) MSA migration may be fairly ubiquitous, particularly at coastal and (or) highaccumulation regions across Greenland and Antarctica; and (ii) can significantly change annual and multiyear MSA concentration averages. Thus, in most cases, caution should be exercised when interpreting polar ice core MSA records, although records that have undergone severe migration could still be useful for inferring decadal and lower-frequency climate variability. © 2017 Author(s).
学科领域	atmospheric transport; climate signal; ice core; paleoclimate; primary production; sea ice; snow accumulation; Antarctica; Arctic; Greenland
语种	英语
scopus关键词	atmospheric transport; climate signal; ice core; paleoclimate; primary production; sea ice; snow accumulation; Antarctica; Arctic; Greenland
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/119316
作者单位	Massachusetts Institute of Technology, Woods Hole Oceanographic Institution Joint Program in Oceanography, Applied Ocean Sciences and Engineering, Woods Hole, MA 02543, United States; Dept. of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; Dept. of Chemistry, Wheaton College, Wheaton, MA, United States
推荐引用方式 GB/T 7714	Osman M.,Das S.B.,Marchal O.,et al. Methanesulfonic acid (MSA) migration in polar ice: Data synthesis and theory[J],2017,11(6).
APA	Osman M.,Das S.B.,Marchal O.,&Evans M.J..(2017).Methanesulfonic acid (MSA) migration in polar ice: Data synthesis and theory.Cryosphere,11(6).
MLA	Osman M.,et al."Methanesulfonic acid (MSA) migration in polar ice: Data synthesis and theory".Cryosphere 11.6(2017).