2010 Arctic

This project will obtain new ice core accumulation records from Combatant Col, Mt. Waddington, in southwestern British Columbia (BC), Canada. Combatant Col is located significantly farther south than other existing ice core sites along the west coast of North America and variations in precipitation tend to be out of phase with those in Alaska and the Yukon. It is anticipated that an annually-resolved record of layer thickness will be recovered at the site to allow for a record of snow accumulation covering the last 200-1000 years. The Combatant Col record, in combination with other existing records of precipitation variability along the western margin of North America, will be used to develop an updated and improved reconstruction of precipitation variability in this region over the last 200-1000 years to address fundamental questions about Pacific decadal scale variability.

The goal of this project is to investigate snow accumulation in the south-eastern sector of the Greenland ice sheet. Snow accumulation rates on the Greenland ice sheet have been significantly underestimated and the missing mass prevents accurate estimates of the overall ice sheet mass balance. The south-eastern sector of the ice sheet contains the largest proportion of the missing mass. Consequently, this study will measure snow accumulation using new and existing firn cores along two transects in the south-east Greenland data void and, by combining the firn core records with ground-penetrating radar surveys, develop continuous accumulation transects between 2500 m and 500 m elevation.

Several 30-meter ice cores will be drilled at the Humboldt and Tunu coring sites in Greenland to update the records obtained from cores taken at these locations in the mid-1990s.

This award will support an investigation of the physical properties and state of snow and firn along a traverse from Thule to Summit Greenland. The scientists will accompany the resupply traverse from Thule to Summit, and make detailed observations of grain size, density and stratigraphy in 1 m deep snow pits and 10 m deep boreholes in firn along a route that crosses all the facies (ablation facies, soaked facies, percolation facies, dry snow facies) of the ice sheet. Techniques to be applied in the field include near infra-red photography, borehole optical stratigraphy and a neutron-scattering probe. A ground-penetrating radar operated along the traverse will provide stratigraphic data that links the stratigraphic information obtained in the snow pits and boreholes. Two shallow ice cores obtained at the beginning and end of the traverse, and snow samples, will be returned to the laboratory for examination of microstructure using micro-computed tomography and brightness temperature using optical and near-infra-red photography.

This project will study the feasibility of cooling air using the firn at Summit Camp in Greenland.

This project, known as NEEM, is being undertaken by 14 nations and is led by the University of Copenhagen. The University of Colorado at Boulder is the lead U.S. institution. The goal is to retrieve ice from the last interglacial episode known as the Eemian Period that ended about 120,000 years ago. The period was warmer than today, with less ice in Greenland that led 5 meter (15-foot) higher sea levels than present--conditions similar to those Earth faces as it warms in the coming century and beyond.