USAP-DC

Melting of snow and ice at the surface of the Antarctic ice sheet can lead to the formation of meltwater lakes, an important precursor to ice-shelf collapse and accelerated ice-sheet mass loss. Understanding the present state of Antarctic surface melt provides a baseline to gauge how quickly melt impacts could evolve in the future and to reduce uncertainties in estimates of future sea-level rise. This project used a suite of complimentary measurements from Earth-observing satellites, ground observations, and numerical climate models to enhance understanding of surface melt and lakes, as well as the processes linking these systems. The project supported the scientific training of a postdoctoral associate, a graduate student, and several undergraduate researchers. In addition, the project aimed to promote public scientific literacy and the broadening of quantitative skills for high-school students through the development and implementation of an educational unit in a partnership with an education and outreach expert and two high school teachers. We identified that surface lake drainages on East Antarctica’s Amery Ice Shelf closely correspond to peaks in the daily amplitude of ocean tides. This research indicates that tidal-induced flexure inherent to the ice shelf grounding zone when combined with sufficient surface meltwater volumes can trigger ice shelf surface lake drainages (Trusel et al., 2022). In addition, we developed new estimates of surface melting across the Antarctic ice sheet using satellite and reanalysis data. First, we developed and implemented a pan-Antarctic ice sheet surface melt detection method applied to C-band Advanced Scatterometer (ASCAT) radar backscatter data. These binary melt presence/absence data were then combined with radar backscatter and ERA5 reanalysis outputs to estimate daily rates of surface meltwater production (in mm of water equivalence) across the Antarctic Peninsula region. These data therefore provide a new, observationally based dataset to investigate the intensity and drivers of surface melting in Antarctica’s highest-melt region, and with which to evaluate climate model simulations. This method and an assessment of the resulting data are the subject of a forthcoming manuscript.

Person	Role
Trusel, Luke	Investigator and contact
Moussavi, Mahsa	Co-Investigator
Pan, Zhuolai	Researcher

Antarctic Glaciology

Award # 2021699

USAP-2021699_1

None in the Database

Repository	Title (link)	Format(s)	Status
Zenodo	ASCAT-ERA5 Antarctic Peninsula Daily Surface Meltwater Production (2007-2022)	netCDF	exists
Zenodo	Trusel et al 2022, Geophysical Research Letters: Publication data and code	Text File; PNG; CSV;	exists
Zenodo	Antarctic ice sheet daily surface melt detection from ASCAT (2007-2022)	netCDF	exists

1. Antarctic Supraglacial Lake Detection Using Landsat 8 and Sentinel-2 Imagery: Towards Continental Generation of Lake Volumes (doi:10.3390/rs12010134)
2. Trusel, L. D., Pan, Z., & Moussavi, M. (2022). Repeated Tidally Induced Hydrofracture of a Supraglacial Lake at the Amery Ice Shelf Grounding Zone. Geophysical Research Letters, 49(7). Portico. (doi:10.1029/2021gl095661)