2017 Ablation Zone Photos
In July 2017 I spent 1 week at a field location in the ablation zone in the Issunguata Sermia catchment. This field site was where scientists from the University of Montana and University of Wyoming installed inclinometers and temperature sensors throughout the ice column in 9 boreholes. I helped to dismantle the field experiments and map the bed using ground penetrating radar.
2017 Ablation Zone Photos
In July 2017 I spent 1 week at a field location in the ablation zone in the Issunguata Sermia catchment. This field site was where scientists from the University of Montana and University of Wyoming installed inclinometers and temperature sensors throughout the ice column in 9 boreholes. I helped to dismantle the field experiments and map the bed using ground penetrating radar.
2017 Ablation Zone Photos
RESEARCH
Advancing our understanding of firn hydrology requires synthesizing observations and model output from the kilometer scale down to the grain scale, which involves combining laboratory, field-based, and remote-sensing datasets.
I take a multiscale approach to study the feedbacks between water and firn structure, to understand the spatial and temporal evolution of water storage modes across ice sheets and ice shelves.
I eager to continue developing projects that examine firn hydrology through targeted field campaigns, laboratory studies, computational analyses of remotely-sensed data products and climate model ouput, and studies of seasonal snowpack processes as analogues for firn hydrology.
Firn Meltwater Hydrology
As melting expands to higher elevations and thus greater extents across ice sheets, porous firn absorbs much of this meltwater, which then refreezes into ice layers or accumulates in perennial aquifers. These processes decouple surface melt from runoff, complicating direct linkages to sea level rise. Future meltwater behavior will diverge between regions with ice layers and those with firn aquifers: ice layers block infiltration and promote lateral runoff, while firn aquifers store meltwater for years to decades. Predictions of where these features develop often rely on coarse climate models and bulk refreezing estimates, overlooking the layered and variable firn structure that governs permeability and capillarity. As a result, firn models struggle to reproduce observed ice layer thicknesses or aquifer depths. Firn also evolves rapidly in the presence of liquid water: saturation accelerates densification and grain growth, while repeated percolation reshapes the firn matrix seasonally. These dynamic feedbacks that are poorly represented in current models make firn both a challenge and a compelling subject for hydrologic research.
Recent Projects
(The Cryosphere, 2024)
Measuring grain size, which is a key microstructural parameter, can be time-consuming, tedious, and subjective. We adapt hyperspectral imaging techniques to improve our ability to observe and monitor firn evolution in cold laboratory environments at the sub-millimeter scale, which allows for quantifying differences in firn structure across climate gradients. This workflow now allows researchers to document fine-scale firn structure in a firn core in hours when these data previously took weeks to collect.
(Journal of Geophysical Research: Earth Surface, 2023)
Firn structure controls how water is routed through the firn layer, but it is constantly being modified in the presence of liquid water. Here, we combined firn model simulations with observations of firn grain size and ice layer stratigraphy in firn cores to identify signatures of meltwater feedbacks on firn microstructure and highlight the key physics driving wet grain metamorphism that need to be included in large-scale firn models.
(Atmosphere, 2020)
Under steady state climate conditions, sites with similar long-term mean accumulation rates and temperatures should have structurally-similar firn columns. This study shows that controls on firn structure are more complicated in sites with similar long-term mean climate conditions. Our results identify key atmospheric drivers, particularly wind speeds and temperature variability (rather than the mean annual temperature), that produce firn columns with different density profiles. Furthermore, we show that firn permeability, a key proxy for firn microstructure, differs systematically from firn density.