2024 Arctic

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. Based on the melting scenarios, a first-order map of sea level rise fingerprints and inundation scenarios for major port cities will be produced.

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.

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 in assessing 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 analyze molecular hydrogen (H2) in an ice core from Summit, Greenland, to reconstruct atmospheric changes in H2 over the past millennium. Using the 700 Drill, the project will drill a new ice core at Summit and extract air from the samples in the field, with subsequent analysis for H2, Ne, and CH4. This will be the first record of past atmospheric H2 prior to the onset of the industrial era. The results will reveal the natural variability in paleo-atmospheric H2 and how it relates to climate change. The resulting data will provide a baseline for assessing how human activities have influenced atmospheric H2 since the preindustrial era. The results of this study will inform global assessments of how the future hydrogen economy will affect atmospheric composition and climate.

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.