气候变化领域集成服务门户(CCPortal): Varying regional δ18O-temperature relationship in high-resolution stable water isotopes from east Greenland

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DOI	10.5194/cp-15-893-2019
	Varying regional δ18O-temperature relationship in high-resolution stable water isotopes from east Greenland
	Holme C.; Gkinis V.; Lanzky M.; Morris V.; Olesen M.; Thayer A.; Vaughn B.H.; Vinther B.M.
发表日期	2019
ISSN	18149324
起始页码	893
结束页码	912
卷号	15 期号:3
英文摘要	This study examines the stable water isotope signal (δ18O) of three ice cores drilled on the Renland peninsula (east Greenland coast). While ice core δ18O measurements qualitatively are a measure of the local temperature history, the δ18O variability in precipitation actually reflects the integrated hydrological activity that the deposited ice experienced from the evaporation source to the condensation site. Thus, as Renland is located next to fluctuating sea ice cover, the transfer function used to infer past temperatures from the δ18O variability is potentially influenced by variations in the local moisture conditions. The objective of this study is therefore to evaluate the δ18O variability of ice cores drilled on Renland and examine the amount of the signal that can be attributed to regional temperature variations. In the analysis, three ice cores are utilized to create stacked summer, winter and annually averaged δ18O signals (1801-2014 CE). The imprint of temperature on δ18O is first examined by correlating the δ18O stacks with instrumental temperature records from east Greenland (1895-2014 CE) and Iceland (1830-2014 CE) and with the regional climate model HIRHAM5 (1980-2014 CE). The results show that the δ18O variability correlates with regional temperatures on both a seasonal and an annual scale between 1910 and 2014, while δ18O is uncorrelated with Iceland temperatures between 1830 and 1909. Our analysis indicates that the unstable regional δ18O-temperature correlation does not result from changes in weather patterns through strengthening and weakening of the North Atlantic Oscillation. Instead, the results imply that the varying δ18O-temperature relation is connected with the volume flux of sea ice exported through Fram Strait (and south along the coast of east Greenland). Notably, the δ18O variability only reflects the variations in regional temperature when the temperature anomaly is positive and the sea ice export anomaly is negative. It is hypothesized that this could be caused by a larger sea ice volume flux during cold years which suppresses the Iceland temperature signature in the Renland δ18O signal. However, more isotope-enabled modeling studies with emphasis on coastal ice caps are needed in order to quantify the mechanisms behind this observation. As the amount of Renland δ18O variability that reflects regional temperature varies with time, the results have implications for studies performing regression-based δ18O-temperature reconstructions based on ice cores drilled in the vicinity of a fluctuating sea ice cover. © Author(s) 2019.
语种	英语
scopus关键词	climate modeling; hydrogen isotope; ice cap; ice core; ice cover; North Atlantic Oscillation; oxygen isotope; paleotemperature; precipitation (climatology); regional climate; sea ice; temperature anomaly; temperature gradient; Arctic; East Greenland; Fram Strait; Greenland; Iceland
来源期刊	Climate of the Past
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/146819
作者单位	Centre for Ice and Climate, Niels Bohr Institute, University of Copenhagen, Copenhagen, Denmark; Department of Geosciences, University of Oslo, Oslo, Norway; Institute of Arctic and Alpine Research, University of Colorado Boulder, Boulder, CO, United States; Danish Climate Centre, Danish Meteorological Institute, Copenhagen, Denmark
推荐引用方式 GB/T 7714	Holme C.,Gkinis V.,Lanzky M.,et al. Varying regional δ18O-temperature relationship in high-resolution stable water isotopes from east Greenland[J],2019,15(3).
APA	Holme C..,Gkinis V..,Lanzky M..,Morris V..,Olesen M..,...&Vinther B.M..(2019).Varying regional δ18O-temperature relationship in high-resolution stable water isotopes from east Greenland.Climate of the Past,15(3).
MLA	Holme C.,et al."Varying regional δ18O-temperature relationship in high-resolution stable water isotopes from east Greenland".Climate of the Past 15.3(2019).