Sensitivity of the Ross Ice Shelf to environmental and glaciological controls

The Ross Ice Shelf (RIS) is currently stable but recent observations have indicated that basal melt rates beneath the ice shelf are expected to increase. It is important to know which areas of the RIS are more sensitive to enhanced basal melting as well as other external forcings or internal materia...

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Bibliographic Details
Main Authors: Baldacchino, Francesca, Morlighem, Mathieu, Golledge, Nicholas R., Horgan, Huw, Malyarenko, Alena
Format: Text
Language:English
Published: 2022
Subjects:
Online Access:https://doi.org/10.5194/tc-2022-50
https://tc.copernicus.org/preprints/tc-2022-50/
Description
Summary:The Ross Ice Shelf (RIS) is currently stable but recent observations have indicated that basal melt rates beneath the ice shelf are expected to increase. It is important to know which areas of the RIS are more sensitive to enhanced basal melting as well as other external forcings or internal material properties to understand how climate change will influence RIS mass balance. In this paper, we use Automatic Differentiation and the Ice Sheet and Sea-level System Model to quantify the sensitivity of the RIS to changes in basal friction, ice rigidity, surface mass balance, and basal melting. Using Volume Above Flotation (VAF) as our quantity of interest, we find that the RIS is most sensitive to changes in basal friction and ice rigidity close to grounding lines and along shear margins of the Siple Coast Ice Streams and Transantarctic Mountains Outlet Glaciers. RIS sensitivity to surface mass balance is uniform over grounded ice, while the sensitivity to basal melting is more spatially variable. With changes in basal melting close to the grounding zones of the Siple Coast Ice Streams and Transantarctic Mountains Outlet Glaciers as well as the pinning points of the RIS including Ross Island, Roosevelt Island, Crary Ice Rise, Steershead Ice Rise and the Shirase Coast Ice Rumples and the ice shelf shear margins having a larger impact on the RIS VAF. Our sensitivity maps allow areas of greatest future vulnerability to be identified.