2023 Arctic

This project will establish a network of instrumented sites to observe transformation of the Greenland Ice sheet’s percolation zone firn layer. Using the IDDO Hand Auger and Sidewinder, repeat cores will be collected over five years to track density and ice content changes, and instrumentation installed in core holes will monitor firn temperature evolution and compaction of the firn layer. The data from these efforts will be of high value to scientists focused on changes in storage capacity of the firn layer, process details of meltwater infiltration in cold firn, and the influence of firn compaction and melt on satellite-observed ice sheet elevation.

The goal of this project is to gather new data to test the sensitivity of the northern Greenland Ice Sheet (GrIS) and its potential to contribute to sea level rise in the future. Specifically, data from the GreenDrill project will better constrain the response of the GrIS to past periods of warmth and address the hypothesis that the northern GrIS is more sensitive to Arctic warming than the southern GrIS. Using the Agile Sub-Ice Geological Drill and the Winkie Drill, the team will drill through the ice at sites in northern Greenland, sample bedrock obtained from those cores, and analyze a suite of cosmogenic nuclides (Beryllium-10, Aluminum-26, Chlorine-36, Carbon-14, and Neon-21) that can act as signatures of changes to the GrIS margin. These data will deliver direct observations of periods when the GrIS was substantially smaller than today and ice sheet margins retreated inland. Results will be incorporated into a numerical ice sheet model with a built-in cosmogenic nuclide module to identify plausible ice sheet histories. The modeling experiments will help understand the mechanisms and climate forcing underlying past periods of ice sheet retreat and help inform predictions of the future. A first-order map of sea level rise fingerprints and inundation scenarios for major port cities will be produced based on the melting scenarios.

This project will conduct geophysical site selection activities for the GreenDrill project. Using the Small Hot Water Drill, team members will drill shot holes to 20 meters depth for seismic sources. Approximately 30 shot holes will be drilled each season.

This project will use the Blue Ice Drill to recover a 150 meter-long, large-diameter ice core to measure methane (CH4) and carbon monoxide (CO) trapped in bubbles in the ice. The researchers will set up a fully operational ice core melter and analysis system in the field to better understand the processes that impact the CH4 and CO gas records from ice cores. High-depth-resolution records of CO, and to a lesser extent CH4, in Arctic ice cores show evidence of non-atmospheric anomalies that are poorly understood. One potential source of such anomalies is biological activity within the ice. Microbes can be active at temperatures well below freezing, and ice cores are subjected to relatively warm temperatures after the ice is extracted from glaciers and ice sheets while they are stored or transported prior to measurement. The project aims to assess the rate of in situ production of CO and methane CH4 in Arctic ice and relate in situ gas production to ice storage conditions, chemistry, and microbiology.

This project aims to recover an ice core at Combatant Col, BC, Canada to reconstruct hydroclimate variability over the last 500 years. Previous work at Combatant Col demonstrates the preservation of annual stratigraphy, water-isotope, and geochemical records reflecting important climate and environmental variables, including atmospheric circulation, snow accumulation, fire activity, and trans-Pacific dust transport. Existing North Pacific ice cores are located exclusively in Alaska and the Yukon. Combatant Col significantly expands the spatial coverage of ice core records while providing a unique hydroclimate record in southwestern British Columbia. This project will conduct detailed radar surveys and ice-flow modeling to better understand the glaciological setting and select the optimal drilling site. During the 2022 field season, radar work and shallow coring using the IDDO Hand Auger will be conducted. During the 2023 field season, a core to bedrock will be retrieved using the Electrothermal Drill. Analysis of the ice core will include water isotope ratios and visual stratigraphy. In combination with high-resolution radar imaging, the core from Combatant Col will be used to determine whether the observed firn-aquifer at this site (liquid water is stored perennially above the firn-ice transition) has been a persistent feature at the site or whether it has formed recently, and to determine its impact on glacier energy balance and dynamics. The core will be archived and made available for additional analyses by the ice core research community.

Weathering is an important process that releases nutrients that are essential for life from rocks and minerals in the Earth’s surface. This project seeks to understand the effect of large glaciers on weathering processes beneath the Greenland Ice Sheet and the consequences for life. During summer, nutrients and other products are flushed out of the Greenland Ice Sheet with water from melting ice. While these products have been sampled in spring and summer, it is not known how weathering processes are different during winter. In this project, researchers will sample the seasonal ice that forms in front of two of Greenland’s glacial outlets, Isunnguata Sermia and Leverett Glacier, during the freezing months to assess the chemistry and microbiology processes that reflect wintertime conditions beneath the ice sheet – periods when input of fresh meltwater is minimal. These samples will increase knowledge of winter conditions under the Greenland Ice Sheet and help better understand the interior portions of the ice sheet, which are largely inaccessible. Such information will help assess past conditions when colder atmospheric conditions resulted in minimal meltwater input through the ice sheet and to the glacial bed. These analyses will inform understanding of the role of glaciers on earth’s nutrient cycles presently, under past ice age conditions, and in a future deglaciating world.

This project will use the IDDO Hand Auger and Sidewinder power drive to drill four 20-meter deep firn cores at Summit, Greenland. The firn cores will span the last 30 years of snow accumulation. They will be used to investigate the trends in methanesulfonic acid (MSA), biogenic sulfate, and total biogenic sulfur over this period when anthropogenic NOx emissions from North America and Europe began to decline (after the mid-1990s). In addition, the researchers will measure ion and MSA concentrations and sulfur isotopes of sulfate in the shallow ice cores. This will yield an additional 16 years of data compared to the current record from an ice core drilled in 2007, allowing the researcher to examine whether the increasing trend in MSA since 2000 C.E. continues as NOx emissions have declined.

This project aims to understand carbon cycling by microorganisms in near-surface glacial ice. Using a Kovacs hand auger, several shallow ice cores 1-2 meters depth will be drilled and analyzed for their microbiology. The researchers aim to understand glacial carbon cycling and estimate the export of organic nutrients to subglacial and proglacial systems. This research is a component of a larger effort to investigate how ecosystems develop, sediments react, and stream water compositions change as glacial retreat exposes landscapes.

Climate warming in the Arctic is thawing frozen soils, also known as permafrost. The thawing of permafrost is reshaping surface topography and increasing the release of greenhouse gases to the atmosphere. The objective of this project is to determine the micro-scale mechanisms driving hot-spot and hot-moment carbon dynamics, for improving predictions of macro-scale carbon balance. As part of the project, the researchers seek to describe biogeochemical consequences across scales in response to abrupt permafrost degradation, with a focal area in the northern Alaska Arctic Coastal Plain. As part of the field validation of ice-wedge degradation stage mapping, the researchers will use the Chipmunk Drill to core the surface of ice-wedges (~1 meter) and make observations of the layering of the ice-cores to determine the age of the surface degradation.