Subsurface Warming of the West Antarctic Continental Shelf Linked to El Niño‐Southern Oscillation

Abstract Recent observations suggest that El Niño–Southern Oscillation (ENSO) impacts basal melting of West Antarctic ice shelves, yet sparse ocean observations limit our understanding of the associated processes. Here we investigate how ENSO events modulate subsurface West Antarctic shelf temperatu...

Full description

Bibliographic Details
Published in:Geophysical Research Letters
Main Authors: Maurice F. Huguenin, Ryan M. Holmes, Paul Spence, Matthew H. England
Format: Article in Journal/Newspaper
Language:English
Published: Wiley 2024
Subjects:
El Niño‐Southern Oscillation
West Antarctica
ocean warming
ocean‐sea ice modeling
interannual variability
Geophysics. Cosmic physics
QC801-809
Antarctic
Amundsen Sea
Antarc*
Antarctica
Ice Shelves
Sea ice
Online Access:https://doi.org/10.1029/2023GL104518
https://doaj.org/article/61d181386985401b9d71d3ccd80328b8
Description
Summary:Abstract Recent observations suggest that El Niño–Southern Oscillation (ENSO) impacts basal melting of West Antarctic ice shelves, yet sparse ocean observations limit our understanding of the associated processes. Here we investigate how ENSO events modulate subsurface West Antarctic shelf temperatures using high‐resolution global ocean‐sea ice model simulations. During El Niño, the subsurface shelf warming between 150 m and the shelf bottom can be up to 0.5°C in front of ice shelves. This warming arises from a weaker Amundsen Sea Low (ASL) and weaker coastal easterlies that reduce on‐shelf Ekman transport of cold surface waters, enabling enhanced transport of warm Circumpolar Deep Water (CDW) onto the shelf. A largely opposite response occurs during La Niña, with a stronger ASL and stronger Ekman transport that results in less cross‐shelf CDW transport and cooling in the subsurface. These findings have implications for interpreting basal melting on interannual to decadal time‐scales in West Antarctica.

Similar Items