Dustin Schroeder of Stanford University
Observing Evolving Subglacial Conditions with Multi-Temporal Radar Sounding
Airborne radar sounding is the primary geophysical method for directly observing conditions beneath ice sheets and glaciers at the catchment to continent scale. From single flow-lines to regional surveys to ice-sheet wide gridded topographic datasets, radar sounding profiles provide information-rich constraints on the englacial and subglacial environment. This can include roughness, lithology, hydrology, thermal state, melt, fabric, and structure for both grounded and floating ice. However, the snap-shot view provided by one-time soundings fails to capture subsurface processes across the time-scales over which they evolve and control ice flow. Doing so requires advancing multi-temporal radar sounding instruments, platforms, and data analysis. For example, point-measurements by ground-based or stationary sounder can be used to produce local time-series observations of englacial and subglacial conditions. However, low-cost, low-power active and/or passive radar-sounder networks can dramatically extend the reach and scope of such measurements. Further, repeat surveys by sled-drawn
or airborne sounders can capture seasonal and interannual subsurface variations. However, digitization of archival radar film is extending the temporal baseline for such comparison by decades, making multi-decadal studies of subsurface changes possible. Finally, the development of autonomous rover, drone, and satellite sounding platforms and systems promise to enable pervasive, stable, and frequent monitoring of subglacial conditions. Here, we discuss the advances, challenges, and the path forward to observing subsurface conditions across the full range spatial and temporal scales at which they occur.
Dustin Schroeder is an assistant professor of geophysics and (by courtesy) of electrical engineering at Stanford University. His research focuses on advancing the scientific and technical foundations of geophysical ice penetrating radar and its use in observing and understanding the interaction of ice and water in the solar system. He is primarily interested in the subglacial and englacial conditions of rapidly changing ice sheets and their contribution to global sea level rise. However, a growing secondary focus of his work is the subsurface exploration of icy moons. He is also interested in the development and application of science-optimized geophysical radar systems. His group of instrument scientists strives to approach problems from both an earth systems science and a radar systems engineering perspective and are actively engaged with the flow of information through each step of the observational science process; from instrument and experiment design, through data processing and analysis, to modeling and inference. This allows them to draw from a multidisciplinary set of tools to test system-scale and process-level hypotheses. Prior to joining, he was a radar systems engineer with NASA’s Jet Propulsion Laboratory at the California Institute of Technology. He is also a science team member for the REASON radar sounder on NASA’s Europa Clipper Mission and is the chair of the Earth and Space Sciences Committee for the National Science Olympiad.