Where sea ice, ocean, and ice shelf meet: ice-ocean co-evolution along the Antarctic Amundsen Sea coast from SWOT using open cloud infrastructure

Principle Investigator: Tasha Snow (Earth System Science Interdisciplinary Center (ESSIC))

Co-Investigator(s): Susan Howard, Ellianna Abrahams, Matthew Siegfried

Collaborator(s): Laurie Padman, James Colliander

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Antarctic glacial ice loss is an area of concern in the global water cycle and in sea level change. Almost all of Antarctic ice loss occurs along the coastline--half resulting from melting by the ocean and half from dynamics related to calving and thinning. Measuring near-glacier-front surfaces at centimeter-scale vertical accuracies and at high frequency repeats is imperative to capturing the rapid and localized processes that influence ice loss. These coastal Antarctic sea ice (ice that forms on the ocean) and ocean surfaces undergo frequent fluctuations directly linked to processes that may impact glacier melting and stability. For instance, as winds shift and sea ice forms along the coastline, coastal currents may move or change in size, impacting heat delivery and ocean circulation at the glacier front. Observing changes in ocean and ice surfaces to discern these processes requires altimetry combined with complex corrections for ocean surface topography. Many of such corrections require using precise, local surface measurements, which have not been acquired in coastal Antarctica. Further, the large data stores required to conduct this work in Antarctica, as well as SWOT science globally, require new processing workflows and state-of-the-art statistical methods to enhance accuracy and properly constrain uncertainties.

The overarching motivation of this project is to improve understanding of processes linking the ocean, sea ice (ice formed on the ocean), and glaciers along the Antarctic coast through a fusion of NASA Surface Water and Ocean Topography (SWOT), NASA Ice, Cloud, and land Elevation Satellite 2 (ICESat-2), and visible and thermal-infrared (heat) imagery datasets also improving the SWOT mission’s broader sea surface height uncertainty quantification and open-source cloud-computing capabilities. Within this overarching motivation we have four specific goals:

1. Create sea surface height maps through time with verified and well-constrained geophysical corrections along the Antarctic coastline (e.g., tides);
2. Evaluate SWOT sea surface height uncertainties in the presence of sea ice using coincident ICESat-2 surface height measurements, and SWOT's ability to measure sea ice height;
3. Assess fluctuations in coastal circulation, ice, and ocean heat processes using a combination of thermal and altimetry data; and
4. Broaden SWOT collaborative open-science and cloud-computing frameworks.

This work will expand our understanding of the complex sea ice-ocean-glacier processes along the coastline that contribute to ice mass loss and are presently challenging to examine due to the inaccessibility of these environments and sparse satellite coverage. These applications will be developed in the Amundsen Sea region of West Antarctica, but will be applicable for other Greenland and Antarctic glacier systems. Our work will also expand cloud-computing paradigms for the oceanographic and cryospheric communities to improve data access, usability, and research transparency for NASA communities.