2012 Arctic

The goal of this project is to analyze firn cores from McCall Glacier in the eastern Brooks Range of Alaska to better understand the processes of internal accumulation of ice within firn. The study will involve extracting firn cores from McCall Glacier to study their change over time to better understand the processes of internal accumulation of ice within firn and the effects of this process on the paleoclimate proxies they are using to interpret a previously drilled deep ice core. The plan is to take about 30 meters of core per year, as a series of about 5 m deep triplicate cores from 2 nearby locations.

The stable isotopic records from the Greenland Ice Sheet are the gold standard for understanding climate variations in the Arctic on decadal to millennial scales. While the basic tenets that underlie interpretation of isotopic information appear robust in a mean sense, meteorological and glaciological processes can confound simple interpretations. Processes of concern are variations in moisture sources, cloud processes, surface ablation, blowing snow and vapor diffusion in the firn. Continuous measurements of the isotopic composition of water vapor and daily measurements of the isotopic composition of freshly-fallen and blowing snow will be made at Summit (Greenland), Eureka (Ellesmere Island) and Reykjavik (Iceland). These will be combined with measurements of the amount, size distribution, and approximate habit of falling and blowing snow, turbulence measurements to evaluate snow lofting, surface latent heat flux (ablation and frost) and energy balance, and remote sensing of polar clouds and atmospheric structure. High-resolution firn cores will be drilled to reconcile the detailed isotopic measurements and modeling with glaciological records.

This project will drill several shallow ice cores in Glacier National Park using the PICO Hand Auger. The goal of the project is to use the recovered ice cores to obtain organic lag deposits. The target lag material the investigators hope to recover will be submitted for radiocarbon dating, environmental DNA analysis, macrofloral analysis, and pollen analysis.