Variability of Arctic climate and sea ice over the past millennium: implications for ice cap mass balance

The core site is on the northern summit plateau of the previously uncored Prince of Wales Icefield (PoW), Ellesmere Island, which lies immediately adjacent to the North Open Water polynya. The accumulation rate in this region is one of the highest measured in the Canadian high Arctic (~0.38 m w.e., Koerner, 2002), and the high elevation of the site (1720 m) means that, while the core provides a record of summer melting, the degree of melting is insufficient to obliterate annually resolved signals in ice core parameters. This site therefore offers a unique opportunity to retrieve cores that can be dated exactly and analyzed at annual or subannual resolution. The site is between the Devon and Agassiz icecaps, that have been cored previously, and so the PoW core will complete a roughly N-S transect of this region.

Core drilling is conducted in the shelter of a longhouse tent, which is also used for core handling and on-site measurements of cores. The drill brings up ice chips on each run. Pollen analysis of this ice will contribute to our understanding of patterns of atmospheric transport to the coring site. For this project, two cores are required as measurements of sulfate isotope composition consumes the whole of one core, so the second core will be used for measurements of core density, melt layers, oxygen isotopes and ion chemistry.