Late-Holocene climate evolution at the WAIS Divide site, West Antarctica: Bubble number-density estimates

J. M. Fegyveresi, R. B. Alley, M. K. Spencer, J. J. Fitzpatrick, E. J. Steig, J. W.C. White, J. R. McConnell, K. C. Taylor

Research output: Contribution to journalArticlepeer-review

15 Scopus citations

Abstract

A surface cooling of ∼1.7°C occurred over the ∼two millennia prior to ∼1700 CE at the West Antarctic ice sheet (WAIS) Divide site, based on trends in observed bubble number-density of samples from the WDC06A ice core, and on an independently constructed accumulation-rate history using annual-layer dating corrected for density variations and thinning from ice flow. Density increase and grain growth in polar firn are both controlled by temperature and accumulation rate, and the integrated effects are recorded in the number-density of bubbles as the firn changes to ice. Numberdensity is conserved in bubbly ice following pore close-off, allowing reconstruction of either paleotemperature or paleo-accumulation rate if the other is known. A quantitative late-Holocene paleoclimate reconstruction is presented for West Antarctica using data obtained from the WAIS Divide WDC06A ice core and a steady-state bubble number-density model. The resultant temperature history agrees closely with independent reconstructions based on stable-isotopic ratios of ice. The ∼1.7°C cooling trend observed is consistent with a decrease in Antarctic summer duration from changing orbital obliquity, although it remains possible that elevation change at the site contributed part of the signal. Accumulation rate and temperature dropped together, broadly consistent with control by saturation vapor pressure.

Original languageEnglish (US)
Pages (from-to)629-638
Number of pages10
JournalJournal of Glaciology
Volume57
Issue number204
DOIs
StatePublished - Sep 2011

All Science Journal Classification (ASJC) codes

  • Earth-Surface Processes

Fingerprint Dive into the research topics of 'Late-Holocene climate evolution at the WAIS Divide site, West Antarctica: Bubble number-density estimates'. Together they form a unique fingerprint.

Cite this