Atmospheric Teleconnections as Potential Drivers of Ross Ice Shelf Basal Melt

Abstract Understanding the processes that regulate basal melt variability beneath Antarctic cold‐cavity ice shelves remains a key challenge for constraining future ice‐sheet mass loss. By linking melt variability directly to the mixing ratios of water masses entering the ice‐shelf cavity over 1993–2018, Pochini et al. (2026, https://doi.org/10.1029/2025JC023103 ) demonstrate that basal melting beneath Ross Ice Shelf is governed primarily by the presence of locally formed High Salinity Shelf Water (HSSW), rather than by intrusions of relatively warm modified Circumpolar Deep Water (mCDW). The dominance of HSSW implies that melt rates in this cold‐cavity system are regulated by processes controlling dense shelf‐water formation on the continental shelf. As HSSW forms through sea‐ice production and brine rejection, its variability may reflect atmospheric forcing that influences winds, sea‐ice transport, and cross‐shelf circulation. We argue that this mechanism links basal melt variability beneath Ross Ice Shelf to large‐scale atmospheric teleconnections—including the Southern Annular Mode, El Niño–Southern Oscillation, and the Amundsen Sea Low—which are projected to evolve under anthropogenic forcing. Changes in these modes may therefore alter the volume and properties of water masses entering the cavity, potentially influencing melt regimes beneath Ross Ice Shelf. This interpretation suggests that atmospheric variability may influence cold‐cavity ice‐shelf stability in ways that are not fully captured in current projections of Antarctic ice‐sheet mass loss and future sea‐level rise.