气候变化领域集成服务门户(CCPortal): Photolytic modification of seasonal nitrate isotope cycles in East Antarctica

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DOI	10.5194/acp-22-15637-2022
	Photolytic modification of seasonal nitrate isotope cycles in East Antarctica
	Akers, Pete D.; Savarino, Joel; Caillon, Nicolas; Magand, Olivier; Le Meur, Emmanuel
发表日期	2022
ISSN	1680-7316
EISSN	1680-7324
起始页码	15637
结束页码	15657
卷号	22 期号:24 页码:21
英文摘要	Nitrate in Antarctic snow has seasonal cycles in nitrogen and oxygen isotopic ratios that reflect its sources and atmospheric formation processes, and as a result, nitrate archived in Antarctic ice should have great potential to record atmospheric chemistry changes over thousands of years. However, sunlight that strikes the snow surface results in photolytic nitrate loss and isotopic fractionation that can completely obscure the nitrate's original isotopic values. To gain insight into how photolysis overwrites the seasonal atmospheric cycles, we collected 244 snow samples along an 850 km transect of East Antarctica during the 2013-2014 CHICTABA traverse. The CHICTABA route's limited elevation change, consistent distance between the coast and the high interior plateau, and intermediate accumulation rates offered a gentle environmental gradient ideal for studying the competing pre- and post-depositional influences on archived nitrate isotopes. We find that nitrate isotopes in snow along the transect are indeed notably modified by photolysis after deposition, and drier sites have more intense photolytic impacts. Still, an imprint of the original seasonal cycles of atmospheric nitrate isotopes is present in the top 1-2 m of the snowpack and likely preserved through archiving in glacial ice at these sites. Despite this preservation, reconstructing past atmospheric values from archived nitrate in similar transitional regions will remain a difficult challenge without having an independent proxy for photolytic loss to correct for post-depositional isotopic changes. Nevertheless, nitrate isotopes should function as a proxy for snow accumulation rate in such regions if multiple years of deposition are aggregated to remove the seasonal cycles, and this application can prove highly valuable in its own right.
学科领域	Environmental Sciences; Meteorology & Atmospheric Sciences
语种	英语
WOS研究方向	Environmental Sciences & Ecology ; Meteorology & Atmospheric Sciences
WOS记录号	WOS:000898904500001
来源期刊	ATMOSPHERIC CHEMISTRY AND PHYSICS
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/273138
作者单位	Trinity College Dublin; Centre National de la Recherche Scientifique (CNRS); Communaute Universite Grenoble Alpes; Institut National Polytechnique de Grenoble; UDICE-French Research Universities; Universite Grenoble Alpes (UGA); Institut de Recherche pour le Developpement (IRD)
推荐引用方式 GB/T 7714	Akers, Pete D.,Savarino, Joel,Caillon, Nicolas,et al. Photolytic modification of seasonal nitrate isotope cycles in East Antarctica[J],2022,22(24):21.
APA	Akers, Pete D.,Savarino, Joel,Caillon, Nicolas,Magand, Olivier,&Le Meur, Emmanuel.(2022).Photolytic modification of seasonal nitrate isotope cycles in East Antarctica.ATMOSPHERIC CHEMISTRY AND PHYSICS,22(24),21.
MLA	Akers, Pete D.,et al."Photolytic modification of seasonal nitrate isotope cycles in East Antarctica".ATMOSPHERIC CHEMISTRY AND PHYSICS 22.24(2022):21.