USAP-DC

This project will develop a record of the stable-isotope ratios of water from an ice core at the South Pole, Antarctica. Water-isotope ratio measurements provide a means to determine variability in temperature through time. South Pole is distinct from most other locations in Antarctica in showing no warming in recent decades, but little is known about temperature variability in this location prior to the installation of weather stations in 1957. The measurements made as part of this project will result in a much longer temperature record, extending at least 40,000 years, aiding our ability to understand what controls Antarctic climate, and improving projections of future Antarctic climate change. Data from this project will be critical to other investigators working on the South Pole ice core, and of general interest to other scientists and the public. Data will be provided rapidly to other investigators and made public as soon as possible.

This project will obtain records of the stable-isotope ratios of water on the ice core currently being obtained at South Pole. The core will reach a depth of 1500 m and an age of 40,000 years. The project will use laser spectroscopy to obtain both an ultra-high-resolution record of oxygen 18/16 and deuterium-hydrogen ratios, and a lower-resolution record of oxygen 17/16 ratios. The high-resolution measurements will be used to aid in dating the core, and to provide estimates of isotope diffusion that constrain the process of firn densification. The novel 17/16 measurement provides additional constraints on the isotope fractionation due to the temperature-dependent supersaturation ratio, which affects the fractionation of water during the liquid-solid condensate transition. Together, these techniques will allow for improved accuracy in the use of the water isotope ratios as proxies for ice-sheet temperature, sea-surface temperature, and atmospheric circulation. The result will be a record of decadal through centennial and millennial scale climate change in a climatically distinct region in East Antarctica that has not been previously sampled by deep ice coring. The project will support a graduate student who will be co-advised by faculty at the University of Washington and the University of Colorado, and will be involved in all aspects of the work.

Person	Role
Steig, Eric J.	Investigator and contact
White, James	Co-Investigator
Schauer, Andrew	Technical Contact
Vaughn, Bruce	Technical Contact

Antarctic Glaciology

Award # 1443105

USAP-1443105_1

None in the Database

Repository	Title (link)	Format(s)	Status
USAP-DC	SP19 Gas Chronology	Excel	exists
USAP-DC	Temperature, accumulation rate, and layer thinning from the South Pole ice core (SPC14)	Excel	exists
USAP-DC	South Pole Ice Core Holocene Major Ion Dataset	CSV; Excel	exists
USAP-DC	South Pole high resolution ice core water stable isotope record for dD, d18O	ASCII	deprecated
USAP-DC	South Pole high resolution ice core water stable isotope record for dD, d18O	ASCII	exists
USAP-DC	Continuous-flow measurements of the complete water isotope ratios (D/H, 17O/16O, 18O/16) from the South Pole ice core	ASCII	exists
USAP-DC	South Pole Ice Core Sea Salt Sodium	CSV; Excel	deprecated

1. Winski, D. A., Fudge, T. J., Ferris, D. G., Osterberg, E. C., Fegyveresi, J. M., Cole-Dai, J., Thundercloud, Z., Cox, T. S., Kreutz, K. J., Ortman, N., Buizert, C., Epifanio, J., Brook, E. J., Beaudette, R., Severinghaus, J., Sowers, T., Steig, E. J., Kahle, E. C., Jones, T. R., Morris, V., Aydin, M., Nicewonger, M. R., Casey, K. A., Alley, R. B., Waddington, E. D., Iverson, N. A., Dunbar, N. W., Bay, R. C., Souney, J. M., Sigl, M., and McConnell, J. R. (2019) The SP19 chronology for the South Pole Ice Core – Part 1: volcanic matching and annual layer counting, Clim. Past, 15, 1793–1808 (doi:10.5194/cp-15-1793-2019)
2. Kahle EC, Holme C, Jones TR, Gkinis V, and Steig EJ (2018) A Generalized Approach to Estimating Diffusion Length of Stable Water Isotopes from Ice-Core Data. Journal of Geophysical Research: Earth Surface, 123, 2377– 2391. (doi:10.1029/2018JF004764)
3. Dütsch M, Blossey PN, Steig EJ, Nusbaumer JM, 2019, Non-equilibrium fractionation during ice cloud formation in iCAM5: evaluating the common parameterization of supersaturation as a linear function of temperature. Journal of Advances in Modeling Earth Systems. (doi:10.1029/2019MS001764)
4. Kahle, E. C., Holme, C., Jones, T. R., Gkinis, V., & Steig, E. J. (2018). A Generalized Approach to Estimating Diffusion Length of Stable Water Isotopes From Ice-Core Data. Journal of Geophysical Research: Earth Surface, 123(10), 2377–2391. (doi:10.1029/2018jf004764)
5. Steig, E.J., Jones, T.R., Schauer, A.J., Kahle, E.C., Morris, V.A., Vaughn, B.H., Davidge, L., White, J.W.C. (2021) Continuous-flow analysis of δ17O, δ18O, and δD of H2O on an ice core from the South Pole. Frontiers in Earth Sciences. (doi:10.3389/feart.2021.640292)
6. Markle, B. R., & Steig, E. J. (2021). Improving temperature reconstructions from ice-core water-isotope records. (doi:10.5194/cp-2021-37)
7. Winski, D. A., Osterberg, E. C., Kreutz, K. J., Ferris, D. G., Cole‐Dai, J., Thundercloud, Z., … Jones, T. R. (2021). Seasonally Resolved Holocene Sea Ice Variability Inferred From South Pole Ice Core Chemistry. Geophysical Research Letters, 48(8). (doi:10.1029/2020gl091602)
8. Buizert, Christo; Fudge, T.J.; Roberts, William H. G.; Steig, Eric J.; Sherriff-Tadano, Sam; Ritz, Catherine; Lefebvre, Eric; Edwards, Jon; Kawamura, Kenji; Oyabu, Ikumi; Motoyama, Hideaki; Kahle, Emma C.; Jones, Tyler R.; Abe-Ouchi, Ayako; Obase, Takashi; Martin, Carlos; Corr, Hugh; Severinghaus, Jeffrey P.; Beaudette, Ross; Epifanio, Jenna; Brook, Edward J.; Martin, Kaden; Chappellaz, Jérôme; Aoki, Shuji; Nakazawa, Takakiyo; Sowers, Todd A.; Alley, Richard; Ahn, Jinho; Sigl, Michael; Severi, Mirko; Dunbar, Nelia W.; Svensson, Anders; Fegyveresi, John; He, Chengfei; Liu, Zhengyu; Zhu, Jiang; Otto-Bliesner, Bette; Lipenkov, Vladimir Y.; Kameda, Takao; Schwander, Jakob. 2021 in press. Antarctic surface temperature and elevation during the Last Glacial Maximum. Science, 372(6546), 1097–1101 (doi:10.1126/science.abd2897)
9. Kahle, E. C., Steig, E. J., Jones, T. R., Fudge, T. J., Koutnik, M. R., Morris, V. A., … White, J. W. C. (2021). Reconstruction of Temperature, Accumulation Rate, and Layer Thinning From an Ice Core at South Pole, Using a Statistical Inverse Method. Journal of Geophysical Research: Atmospheres, 126(13). (doi:10.1029/2020jd033300)
10. Markle, B. R., & Steig, E. J. (2022). Improving temperature reconstructions from ice-core water-isotope records. Climate of the Past, 18(6), 1321–1368. (doi:10.5194/cp-18-1321-2022)