How does meltwater affect the flow of ice off of Greenland and into the ocean?
Sarah Das watching a torrential meltwater stream in western Greenland
We study the Greenland Ice Sheet: how is it melting, how is the ice flowing into the ocean, and what are the interactions between those processes?
Why Greenland?
The Greenland Ice Sheet is currently the fastest-accelerating source of global sea-level rise. Understanding how Greenland discharge is likely to continue or change in the future is crucial as cities plan for high waters. Storm surges, for example from hurricanes, underscore the devastation that higher sea levels can wreak on coastal cities and our connected economy and highlight the importance of research into the ice sheets behind sea-level rise.
Meltwater flows into a nascent moulin near the bottom of a supraglacial lake basin in western Greenland.
Two faces of Greenland
Just as the United States has drastically different weather depending on where you are, so does Greenland: the east coast is blizzard central (roughly triple the annual snowfall in Buffalo), while the west coast is downright balmy (mean annual temperatures are similar to average January temperatures in Buffalo), by Greenland standards. On both coasts, despite the cold climates, temperatures regularly crack 0°C each summer, so the ice melts for a few weeks or months. On the west coast, this meltwater forms rushing blue rivers under the “warm” (5°C) summer sun, while on the east coast, snowstorms quickly bury the meltwater into glacier igloos.
We are currently investigating how these patterns affect the fate of meltwater in each place. So far, we know that the meltwater descends to the base of the ice sheet thousands of feet below, from where it has a clear path to the ocean. But the rate at which the water gets there affects the flow rate of ice sheet itself, and this rate varies quite a bit from eastern to western Greenland. We use numerical models, enhanced by remote-sensing observations, to probe the effects of meltwater on ice flow.
Helheim Glacier (back), which flows into Sermilik Fjord (foreground) in eastern Greenland. Here you can see small icebergs floating within the sea ice mélange in the fjord. Operation IceBridge flight, May 2017
Models informed by observations
We also leverage the extensive observations from the UB Remote Sensing Laboratory into developing numeric models that predict how the ice flows. Glaciologists are continually working to make our ice-sheet models, which are based on physics spanning the most basic level (Newton’s Second Law) to complexities at the microscopic level (rheology of ice), more complete. The ice-sheet models are already quite good, but as we compare them to the wealth of observations provided by NASA and other remote-sensing programs, we are able to add new processes to them that make them even more accurate. Our work is to identify missing processes (e.g. the transit of meltwater to the ice-sheet base) and works to incorporate them into ice-sheet models
Strain rates (colored arrows) measured across a crevasse field (central arc of image), two supraglacial lake basins (dark round features in the right portion of the image), and a zone of crevasse healing (top left).
What will be the fate of the Greenland Ice Sheet, and how quickly will we see it happen?
Early season melt (May 2017) on a tributary to Fenris Glacier, eastern Greenland.
Student research opportunities
I am always looking for motivated students with skills in, or interest and motivation in developing skills in, mathematical glaciology, including numerical modeling and remote sensing. I am particularly interested in working with students from minoritized backgrounds. Members of the Glacier Modeling Lab work together to create an academically supportive and anti-racist community.
My primary goal as a professor is to help my students succeed through growth in thinking capacity, research aptitude, and personal fulfillment in the UB Glacier Modeling Lab. If a certain research topic interests you, send me an email or drop in to my office to tell me why you’d be a good fit!
