Baroclinic ocean response to climate forcing regulates decadal variability of ice-shelf melting in the Amundsen Sea ...

• Main Authors: Silvano, Alessandro, Holland, Paul, Naughten, Kaitlin, Dragomir, Oana, Dutrieux, Pierre, Jenkins, Adrian, Si, Yidongfang, Stewart, Andrew, Peña Molino, Beatriz, Janzing, Gregor, Dotto, Tiago, Naveira Garabato, Alberto
• Format: Article in Journal/Newspaper
• Language: unknown
• Published: GFZ German Research Centre for Geosciences 2023
• Subjects: Amundsen Sea; Pacific; Ice Shelf; Ice Shelves
• Online Access: https://dx.doi.org/10.57757/iugg23-0161; https://gfzpublic.gfz-potsdam.de/pubman/item/item_5016397

<!--!introduction!--> Warm ocean waters drive rapid ice-shelf melting in the Amundsen Sea. The ocean heat transport toward the ice shelves is associated with the Amundsen Undercurrent, a near-bottom current that flows eastward along the shelf break and transports warm waters onto the continental shelf via troughs. Here we use a regional ice-ocean model to show that, on decadal time scales, the undercurrent's variability is baroclinic (depth-dependent). Decadal ocean surface cooling in the tropical Pacific results in cyclonic wind anomalies over the Amundsen Sea. These wind anomalies drive a westward perturbation of the shelf-break surface flow and an eastward anomaly (strengthening) of the undercurrent, leading to increased ice-shelf melting. This contrasts with shorter time scales, for which surface current and undercurrent covary, a barotropic (depth-independent) behavior previously assumed to apply at all time scales. This suggests that interior ocean processes mediate the decadal ice-shelf response ... : The 28th IUGG General Assembly (IUGG2023) (Berlin 2023) ...