Alison Banwell

My research predominantly focuses on the Earth's two largest ice sheets, Greenland and Antarctica, including their ice shelves, which for Antarctica in particular, have a crucial role in buttressing inland ice from flowing more rapidly into the ocean. As the planet warms in response to human-induced climate change, it is imperative that we better understand these dynamics in order to predict future rates of ice loss to the oceans.

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, 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.

Antarctic ice shelf melt, hydrology and dynamics: Ice shelves, which are the floating extensions of glaciers on land, surround ~75% of Antarctica and have an important role in regulating the rate that inland glacier ice is lost 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 ice-shelf 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.