This is the project summary published by NSF.
Collaborative Research: Investigating the influence of sea-surface variability on ice sheet mass balance and outlet glacier behavior using records from Disko Bugt, West Greenland
S. B. Das, M. J. Evans, K. E. Frey, B. E. Smith
Intellectual Merit: Recent changes, including the dramatic speedups of several large outlet glaciers, and increased rates of surface melting, have increased Greenland’s contribution to sea-level rise from near zero in the 1990s to a large negative imbalance today. Poor knowledge of the processes driving these changes is one of the main limitations on prediction of future ice sheet contributions to sea level rise. An increasing number of observations point towards the influence of coupled ocean-ice-atmospheric processes in modulating ice sheet mass balance and outlet glacier behavior, but most studies are limited to the past few decades restricting our ability to extrapolate these relationships over longer time periods, given their high inter-annual variability. We are proposing to further our understanding of ocean-ice-atmosphere interaction around the Jakobshavn Isbrae and Disko Bay region of west Greenland, with a particular focus on the role of sea surface temperature and sea ice variability in modulating past outlet glacier behavior and ice sheet/cap mass balance (snowfall and melt) over the past two centuries. We will reconstruct past environmental conditions in the Disko and Baffin Bay region based on new glaciochemical and stratigraphic records from three 100-m deep ice cores, several firn cores, and geophysical studies from three sites surrounding Disko Bay. Our primary field activities in 2013 include: site reconnaissance on ice caps on Disko Island and Nuussuaq Peninsula and collection of shallow cores at both ice cap sites and on the western Greenland margin (to overlap with the last ~10–30 years of the satellite-era.) Our main ice-coring activity will follow in 2014 at all 3 sites where we plan to collect ~100-m deep ice-cores. Our field activities will be followed by extensive lab and computational work to derive climate reconstructions from these cores. These results will complement recent glaciological studies of regional ice dynamic behavior, as well as recent paleoceanographic and glacial geologic reconstructions of conditions from this area and era.
Broader Impacts: The Greenland Ice Sheet contribution to sea level rise over the next century is largely unknown; estimates range from a few centimeters to over one meter. Planning within such a large range of uncertainty has extremely high economic and social costs. Our investigation into the coupled ocean-atmosphere-ice processes governing ice sheet mass balance and outlet glacier behavior is aimed at reducing uncertainties that have severely limited our ability to estimate future ice-sheet contributions to sea level, and are thus of broad societal, as well as scientific, interest. Das and Frey will each supervise a full-time Ph.D. student, and Evans will supervise undergraduate research assistants and senior theses, working on this project. All PIs will also continue their efforts sharing current research results through coursework and seminars. We will also partner with M. Bingham, a high school science teacher at Milton Academy in Milton, MA. Bingham will be involved throughout the multi-year project, including one of the field seasons, giving him a unique professional development opportunity to enhance both his, and Milton Academy’s, inquiry based pedagogy by participating in the scientific process from start to finish. Bingham will disseminate this pedagogy/curriculum to other STEM K-12 teachers. Bingham will also make presentations to multiple age groups outside his typical classes including live phone calls to classrooms from the field. In addition, Milton’s proximity to WHOI, Wheaton, and Clark will allow for interaction between Milton students and all project students and PIs within this project. This effort will build on an existing collaboration between Milton and Wheaton students to design and implement field and lab-based projects.