USAP-DC

0538657
Severinghaus
This award supports a project to develop high-resolution (20-yr) nitrogen and oxygen isotope records on trapped gases in the WAIS Divide ice core (Antarctica), with a comparison record for chronological purposes in the GISP2 (Greenland) ice core. The main scientific objective is to provide an independent temperature-change record for the past 100,000 years in West Antarctica that is not subject to the uncertainty inherent in ice isotopes (18O and deuterium), the classical paleothermometer. Nitrogen isotopes (Delta 15N) in air bubbles in glacial ice record rapid surface temperature change because of thermal fractionation of air in the porous firn layer, and this isotopic anomaly is recorded in bubbles as the firn becomes ice. Using this gas-based temperature-change record, in combination with methane data as interpolar stratigraphic markers, the proposed work will define the precise relative timing of abrupt warming in Greenland and abrupt cooling at the WAIS Divide site during the millennial-scale climatic oscillations of Marine Isotopic Stage 3 (30-70 kyr BP) and the last glacial termination. The nitrogen isotope record also provides constraints on past firn thickness, which inform temperature and accumulation rate histories from the ice core. A search for possible solar-related cycles will be conducted with the WAIS Divide Holocene (Delta 15N.) Oxygen isotopes of O2 (Delta 18Oatm) are obtained as a byproduct of the (Delta 15N) measurement. The gas-isotopic records will enhance the value of other atmospheric gas measurements in WAIS Divide, which are expected to be of unprecedented quality. The high-resolution (Delta 18Oatm) records will provide chronological control for use by the international ice coring community and for surface glacier ice dating. Education of a graduate student, and training of a staff member in the laboratory, will contribute to the nation's human resource base. Outreach activities in the context of the International Polar Year will be enhanced. International collaboration is planned with the laboratory of LSCE, University of Paris.

Person	Role
Haines, Skylar	Investigator
Mayewski, Paul A.	Co-Investigator
Orsi, Anais J.	Co-Investigator
Kurbatov, Andrei V.	Co-Investigator
Severinghaus, Jeffrey P.	Investigator

Antarctic Glaciology

Award # 0538657

NSIDC-0637_1
NSIDC-0635_1
NSIDC-0660_1
severinghaus_0538657

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	WAIS Divide d18Oatm and Siple Dome/WAIS Divide composite and individual delta epsilon LAND	Excel	exist
USAP-DC	d15N and d18O of air in the WAIS Divide ice core	Excel	exists
USAP-DC	Ultra-High Resolution LA-ICP-MS Results: DO-21 Rapid Warming Event	Excel	exist
USAP-DC	Borehole Temperature Measurement in WDC05A in January 2008 and January 2009	ASCII	exist
USAP-DC	Low-res d15N and d18O of O2 in the WAIS Divide 06A Deep Core	Excel	exist

1. Buizert, C., K.M. Cuffey, J.P. Severinghaus, D. Baggenstos, T.J. Fudge, E.J. Steig, T.A. Sowers, E.J. Brook, R.H. Rhodes, H. Cheng, L.R. Edwards, M. Sigl, J.R. McConnell, and K.C. Taylor (2015). The WAIS Divide deep ice core WD2014 chronology - Part 1: Methane synchronization (68-31 ka BP) and the gas age-ice age difference, Clim. Past, 11, 153-173, doi:10.5194/cp-11-153-2015. (doi:10.5194/cp-11-153-2015)
2. Cuffey, K.M., Clow, G.D., Steig, E.J., Buizert, C., Fudge, T.J., Koutnik, M., Waddington, E.D., Alley, R.A. and Severinghaus, J.P. 2016. Deglacial temperature history of West Antarctica, Proceedings of the National Academy of Sciences, 113(50), p. 14249-1425. doi: 10.1073/pnas.1609132113. (doi:10.1073/pnas.1609132113)
3. McConnell, J. R., Burke, A., Dunbar, N. W., Köhler, P., Thomas, J. L., Arienzo, M. M., … Winckler, G. (2017). Synchronous volcanic eruptions and abrupt climate change ∼17.7 ka plausibly linked by stratospheric ozone depletion. Proceedings of the National Academy of Sciences, 114(38), 10035–10040. (doi:10.1073/pnas.1705595114)
4. Buizert, C., Cuffey, K. M., Severinghaus, J. P., Baggenstos, D., Fudge, T. J., Steig, E. J., … Taylor, K. C. (2014). The WAIS-Divide deep ice core WD2014 chronology – Part 2: Methane synchronization (68–31 ka BP) and the gas age-ice age difference. Climate of the Past Discussions, 10(4), 3537–3584. (doi:10.5194/cpd-10-3537-2014)
5. Orsi, A. J., Cornuelle, B. D., & Severinghaus, J. P. (2012). Little Ice Age cold interval in West Antarctica: Evidence from borehole temperature at the West Antarctic Ice Sheet (WAIS) Divide. Geophysical Research Letters, 39(9), n/a–n/a. (doi:10.1029/2012gl051260)