Greenland Glaciochemical Study

The recent development of a new method for continuous, high-resolution ice-core analyses called Continuous Flow Analysis with Trace Elements (CFA-TE) makes possible for the first time continuous, high-resolution and exactly co-registered glaciochemical measurements of a broad spectrum of chemical species, trace elements, and isotopes. Under NASA and NSF funding, Joe McConnell at the Desert Research Institute (DRI), Nevada System of Higher Education, collected a number of shallow (< 30 m) and intermediate (80 to 150 m) ice cores in Greenland during the 2003 and 2004 field seasons that will be analyzed with CFA-TE.

The primary objective of NSF funded coring is to develop spatially distributed, continuous, multi-century glaciochemical records of over 20 chemical species, trace elements, and isotopes with unprecedented temporal resolution (50 - 100 samples per year) using two ~150-m cores collected in west central Greenland in 2003 and a new ~80 m core collected at Summit. These unique records will significantly expand possible applications of glaciochemical data to the study of a range of environmental and global change issues.

Also, as part of ongoing research on the mass balance of the Greenland ice sheet and its impact on sea level, McConnell collected 8 shallow ice cores in southern Greenland in 2003. The cores were located in regions of the ice sheet with little or no previous ice core measurements in order to improve net accumulation measurements for specific drainage basins. Two additional ~80 m cores were collected by Sarah Das and colleagues in 2003 for melt frequency studies and analyzed by McConnell using CFA-TE to provide exact dating at annual and sub-annual time scales.

Regional scale changes in atmospheric and oceanic circulation result in changes in net snow accumulation in different parts of the Greenland ice sheet, leading to changes in the local mass balance. As part of a new NASA project, McConnell and colleagues collected two intermediate and two shallow cores in 2004 along a 220 km east-west snowmobile traverse of the southern ice sheet called ACT (Arctic Circle Traverse). Ground penetrating radar was used to connect the core records. The ACT ice cores will be analyzed with CFA-TE and temporal and spatial changes in elemental concentrations and isotopes will be used as tracers, together with air mass back-trajectories, to characterize changes in atmospheric circulation that drive different accumulation patterns in southern Greenland.

All intermediate cores drilled in 2003 and 2004 were collected using the ICDS 4-inch drill. ICDS also supplied the drillers: Louise Albershardt and Sue Root in 2003 and Jay Kyne and Beth Bergeron in 2004. The ICDS sidewinder 4-inch portable drill was used to collect all but two of the shallow cores in 2003 and 2004.