Alison Banwell

Greenland Ice Sheet melt and hydrology: Ice dynamics and ice loss to oceans are strongly influenced by surface meltwater accessing the ice-sheet bed, sometimes due to rapid surface lake drainage events. Previously, I developed a physically-based coupled melt/hydrology model to simulate surface melting and the subsequent routing of meltwater under both current and future warming scenarios. Two field campaigns in Greenland provided data to constrain this model. Additionally, I employ remote-sensing techniques, such as satellite optical imagery, synthetic aperture radar (SAR) data, lidar altimetry data, and digital elevation models, to track changes in surface hydrology automatically. For instance, we used statistical analysis to identify geophysical controls on rapid drainage events and applied a convolutional neural network to SAR data for automatic buried lake detection. Most recently we have developed an automated machine learning time series classification method to categorize draining, refreezing, and buried lakes on an ice-sheet-wide scale

Antarctic ice shelf melt, hydrology and dynamics: Ice shelves, which are the floating extensions of grounded glaciers, surround ~75% of Antarctica and have an important role in regulating inland glacier ice loss to the ocean. Surface melting leads to dense networks of surface meltwater lakes, which periodically fill and drain, inducing stress changes that lead to large ice-shelf break-up events. To better understand these processes, my research uses a combination of modeling, in-situ field observations, and satellite remote-sensing techniques. For example, we simulated the rapid break-up of the Larsen B Ice Shelf in 2002 due to the chain-reaction style drainage of ~3000 lakes. Later, two seperate NSF-funded field projects on the McMurdo and George VI ice shelves, respectively, provided the first in-situ field observations of ice-shelf flexure and fracture in response to the filling and drainage of surface meltwater lakes. Recently, we have also developed a new method to quantify Antarctic-wide ice-shelf surface melt volume by combining satellite microwave data and a sophisticated snow model.