气候变化领域集成服务门户(CCPortal): Baffin Bay sea ice extent and synoptic moisture transport drive water vapor isotope (δ18O; δ2H; and deuterium excess) variability in coastal northwest Greenland

CCPortal

DOI	10.5194/acp-20-13929-2020
	Baffin Bay sea ice extent and synoptic moisture transport drive water vapor isotope (δ18O; δ2H; and deuterium excess) variability in coastal northwest Greenland
	Akers P.D.; Kopec B.G.; Mattingly K.S.; Klein E.S.; Causey D.; Welker J.M.
发表日期	2020
ISSN	1680-7316
起始页码	13929
结束页码	13955
卷号	20 期号:22
英文摘要	At Thule Air Base on the coast of Baffin Bay (76.51◦ N, 68.74◦ W), we continuously measured water vapor isotopes (δ18O, δ2H) at a high frequency (1 s−1) from August 2017 through August 2019. Our resulting record, including derived deuterium excess (dxs) values, allows an analysis of isotopic–meteorological relationships at an unprecedented level of detail and duration for high Arctic Greenland. We examine isotopic variability across multiple temporal scales from daily to interannual, revealing that isotopic values at Thule are predominantly controlled by the sea ice extent in northern Baffin Bay and the synoptic flow pattern. This relationship can be identified through its expression in the following five interacting factors: (a) local air temperature, (b) local marine moisture availability, (c) the North Atlantic Oscillation (NAO), (d) surface wind regime, and (e) land-based evaporation and sublimation. Each factor’s relative importance changes based on the temporal scale and in response to seasonal shifts in Thule’s environment. Winter sea ice coverage forces distant sourcing of vapor that is isotopically light from fractionation during transport, while preventing isotopic exchange with local waters. Sea ice breakup in late spring triggers a rapid isotopic change at Thule as the newly open ocean supplies warmth and moisture that has ∼ 10 and ∼ 70 higher δ18O and δ2H values, respectively, and ∼ 10 lower dxs values. Sea ice retreat also leads to other environmental changes, such as sea breeze development, that radically alter the nature of relationships between isotopes and many meteorological variables in summer. On synoptic timescales, enhanced southerly flow promoted by negative NAO conditions produces higher δ18O and δ2H values and lower dxs values. Diel isotopic cycles are generally very small as a result of a moderated coastal climate and the counteracting isotopic effects of the sea breeze, local evaporation, and convection. Future losses in Baffin Bay’s sea ice extent will likely shift mean annual isotopic compositions toward more summer-like values, and local glacial ice could potentially preserve isotopic evidence of past reductions. These findings highlight the influence that the local environment can have on isotope dynamics and the need for dedicated, multiseason monitoring to fully understand the controls on water vapor isotope variability. © Author(s) 2020. This work is distributed under
英文关键词	atmospheric chemistry; atmospheric transport; coastal zone; flow pattern; isotopic analysis; North Atlantic Oscillation; sea ice; synoptic meteorology; water vapor; Arctic; Arctic Ocean; Baffin Bay [Arctic Ocean]; Greenland; Thule Air Base
语种	英语
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/168953
作者单位	Institut des Géosciences et l’Environnement, CNRS, Saint Martin d’Hères, 38400, France; Department of Biological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, United States; Institute of Earth, Ocean, and Atmospheric Sciences, Rutgers University, Piscataway, NJ 08854, United States; Department of Geological Sciences, University of Alaska Anchorage, Anchorage, AK 99508, United States; Ecology and Genetics Research Unit, University of Oulu, Oulu, 90014, Finland; University of the Arctic (UArctic), C/o University of Lapland, Rovaniemi, 96101, Finland
推荐引用方式 GB/T 7714	Akers P.D.,Kopec B.G.,Mattingly K.S.,et al. Baffin Bay sea ice extent and synoptic moisture transport drive water vapor isotope (δ18O; δ2H; and deuterium excess) variability in coastal northwest Greenland[J],2020,20(22).
APA	Akers P.D.,Kopec B.G.,Mattingly K.S.,Klein E.S.,Causey D.,&Welker J.M..(2020).Baffin Bay sea ice extent and synoptic moisture transport drive water vapor isotope (δ18O; δ2H; and deuterium excess) variability in coastal northwest Greenland.Atmospheric Chemistry and Physics,20(22).
MLA	Akers P.D.,et al."Baffin Bay sea ice extent and synoptic moisture transport drive water vapor isotope (δ18O; δ2H; and deuterium excess) variability in coastal northwest Greenland".Atmospheric Chemistry and Physics 20.22(2020).