SGER: High Resolution Radar Mapping of Ice Thickness and Near-Surface Layers in Northeast Greenland

University Of Kansas Center For Research Inc, Lawrence KS

Investigators

Abstract

ABSTRACT Laird OPP-0608181 The Principal Investigators propose to use two compact, wideband radars to map near - surface and deep internal ice layers around an ice core to be drilled on the 540 m thick, coastal Flade Isblink Ice Cap in NE Greenland in May - June, 2006. This work will be part of a collaborative, multi-national effort led by Danish researchers to characterize the relationship between climate change and the evolution of the ice caps and sea ice. The low-power radars, their antennas and a portable generator will be mounted on a Nansen sled and pulled behind a snowmobile in an approximately 9 km x 9 km grid centered on the core drill site to map accumulation rates, accumulation variability, thickness and flow properties across the dome. The two radar systems have already been developed and tested extensively in both Greenland and Antarctica and can be deployed without additional modifications. The proposal leverages additional logistical support provided by the University of Copenhagen team. All collaborators have agreed to share data sets. The costs for this project, such as equipment maintenance, data processing and analysis, and publication of results will be borne by the CReSIS (Center for Remote Sensing of Ice Sheets). Intellectual Merit Little is known about paleoclimatic change in northern Greenland and how it is related to paleoclimatic change in the rest of Greenland. The scientific merit will be the exploration of this remote and little studied region with ground penetrating radar to provide input to, and validation of, high-resolution numerical models of ice sheet dynamics and evolution for predicting climate change and sea - level rise. Ice core and radar studies provide a more complete picture of the evolution of the ice cap and the climate history of that region. Radar measurements are critical for extrapolating the internal structure and history of the ice laterally beyond the core site, which is effectively a point source on the ice cap, for use in ice sheet models. At the same time, ice core temperature and density measurements are necessary to convert the radar profiles from travel time into depth domain for accurate near - surface accumulation profiles and ECM (Electrical Conductivity Measurements) and depth/age profiles are required to provide ground truth for mapping deep isochrones due to volcanic activity. The radar profiles will also: 1) resolve ice sheet thickness and layer deformation, 2) expand on internal layer structure and ice flow properties, and 3) look at topographic effects on accumulation. With the aid of the accumulation profiles, the Principal Investigators hope to learn if the ice cap survived the early Holocene Climatic Optimum and why it is growing at a rate of about 50 cm/y when the mass balance of the ice sheet is slightly negative and thinning predominates in lower, coastal areas. Broader Impacts An electrical engineering graduate student will be directly involved in this project, both in the field and in the lab, assisting with radar operation, data analysis and visualization, linking radar data to glaciological issues addressed by this project. The research group currently has a strong outreach program and will leverage CReSIS resources to: 1) provide a journal and pictures for posting on our website, 2) develop a travelogue and course materials for K -12 students, and 3) present lectures on Flade Isblink activities for students at Haskell Indian Nations University. All ice core and radar data from this project will be submitted to NSIDC within one year after returning from the field.