Englacial Temperature Profile

Englacial Temperature Profile

The temperature profile of ice sheets is critical for understanding ice deformation, flow, and basal sliding, while also serving as a key input for validating ice sheet models. Direct observations of the englacial temperature profile are limited to borehole locations, but recently low-frequency microwave sensors, like those on ESA’s L-band Soil Moisture and Ocean Salinity (SMOS) satellite, have enabled remote temperature retrievals. Under the framework of the 4DAntarctica project, a new methodology was implemented with an advanced ice temperature emulator and retrieval uncertainty quantification (Leduc-Leballeur et al., 2021).

The 5DAIS project will further develop these methodologies with a focus on improving retrievals in West Antarctica by developing a new electromagnetic model, testing different sensor configurations, and leveraging external datasets. Moreover, some investigations will be performed over the larger ice shelves (e.g. Ross, Ronne) to understand if information about ice temperature can be retrieved in these places.

Ice temperature retrieved from SMOS observations at (left) 500 m and (center) 1500 m in depth

Summary of the englacial temperature profile datasets planned within 5DAIS:

• The 5DAIS dataset will be an updated version of the ice temperature profiles estimated over Antarctica where the ice sheet is thicker than 1000 m. The product will have a spatial resolution of 25 km x 25 km.
• Uncertainties will be provided along each profile, as well as a retrieval quality flag map.
• An indicator of cold/warm base with its uncertainty will be delivered as a secondary information.