Fig. 7: Schematic illustrating the impacts of the Southern Annular Mode (SAM) on the dense shelf water (DSW) formation in the Ross Sea in 2000–2014 and the physical mechanisms.
From: Evidence for large-scale climate forcing of dense shelf water variability in the Ross Sea
In (a) 2000–2014, the Amundsen Sea Low moved eastward and became weaker, exerting less influence on the wind field over the western Ross Sea. SAM in turn dominates the interannual variability of wind. b The shift toward a positive SAM phase enhances the westerlies over the western Ross Sea and decreases the surface air temperature, which promote sea ice production in the Terra Nova Bay Polynya (TNBP) and the Ross Ice Shelf polynya (RISP). Inceased ice production enhances the DSW formation in the polynyas, finally leading to increased DSW volume on the continental shelf and slope and greater Antarctic Bottom Water (AABW) volume in the open ocean. The processes in (c) are opposite to those in (b) when SAM shifts toward its negative phase.
