气候变化领域集成服务门户(CCPortal): Non-climatic signal in ice core records: Lessons from Antarctic megadunes

CCPortal

DOI	10.5194/tc-10-1217-2016
	Non-climatic signal in ice core records: Lessons from Antarctic megadunes
	Ekaykin A.; Eberlein L.; Lipenkov V.; Popov S.; Scheinert M.; Schroder L.; Turkeev A.
发表日期	2016
ISSN	19940416
卷号	10 期号:3
英文摘要	We present the results of glaciological investigations in the megadune area located 30 km to the east of Vostok Station (central East Antarctica) implemented during the 58th, 59th and 60th Russian Antarctic Expedition (January 2013-2015). Snow accumulation rate and isotope content (δD, δ18O and δ17O) were measured along the 2 km profile across the megadune ridge accompanied by precise GPS altitude measurements and ground penetrating radar (GPR) survey. It is shown that the spatial variability of snow accumulation and isotope content covaries with the surface slope. The accumulation rate regularly changes by 1 order of magnitude within the distance < 1 km, with the reduced accumulation at the leeward slope of the dune and increased accumulation in the hollow between the dunes. At the same time, the accumulation rate averaged over the length of a dune wave (22mmw.e.) corresponds well with the value obtained at Vostok Station, which suggests no additional wind-driven snow sublimation in the megadunes compared to the surrounding plateau. The snow isotopic composition is in negative correlation with the snow accumulation. Analysing dxs/δD and 17O-excess/δD slopes (where dxs =δD-8· δ18O and 17O-excessDln(δ17O/1000 + 1)-0.528 · In(δ18O/1000+1)), we conclude that the spatial variability of the snow isotopic composition in the megadune area could be explained by post-depositional snow modifications. Using the GPR data, we estimated the apparent dune drift velocity (4.6 ± 1.1myr-1). The full cycle of the dune drift is thus about 410 years. Since the spatial anomalies of snow accumulation and isotopic composition are supposed to drift with the dune, a core drilled in the megadune area would exhibit the non-climatic 410-year cycle of these two parameters. We simulated a vertical profile of snow isotopic composition with such a non-climatic variability, using the data on the dune size and velocity. This artificial profile is then compared with the real vertical profile of snow isotopic composition obtained from a core drilled in the megadune area. We note that the two profiles are very similar. The obtained results are discussed in terms of interpretation of data obtained from ice cores drilled beyond the megadune areas. © 2016 Author(s).
学科领域	accumulation rate; climate signal; dune; GPS; ground penetrating radar; ice core; isotopic composition; sublimation; vertical profile; Antarctica; East Antarctica; Vostok Station
语种	英语
scopus关键词	accumulation rate; climate signal; dune; GPS; ground penetrating radar; ice core; isotopic composition; sublimation; vertical profile; Antarctica; East Antarctica; Vostok Station
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/119635
作者单位	Climate and Environmental Research Laboratory, Arctic and Antarctic Research Institute, 38 Beringa st., St.-Petersburg, 199397, Russian Federation; St. Petersburg State University, St.-Petersburg, 199178, Russian Federation; Technische Universitat Dresden, Institut fur Planetare Geodasie, Dresden, 01062, Germany; Polar Marine Geological Research Expedition, 24 Pobedy st., Lomonosov, 198412, Russian Federation
推荐引用方式 GB/T 7714	Ekaykin A.,Eberlein L.,Lipenkov V.,et al. Non-climatic signal in ice core records: Lessons from Antarctic megadunes[J],2016,10(3).
APA	Ekaykin A..,Eberlein L..,Lipenkov V..,Popov S..,Scheinert M..,...&Turkeev A..(2016).Non-climatic signal in ice core records: Lessons from Antarctic megadunes.Cryosphere,10(3).
MLA	Ekaykin A.,et al."Non-climatic signal in ice core records: Lessons from Antarctic megadunes".Cryosphere 10.3(2016).