Deep Waters originating in the Atlantic, Indian and Pacific upwell in the Southern Ocean, with the warmest waters, of Indian and Pacific origin (Upper Circumpolar Deep Water) reaching the Antarctic shelves in the eastern South Pacific sector (Bellingshausen Sea).  The pathways of these deep waters to the upper Southern Ocean is strongly mitigated by topography.  Topographic steering of the southern boundary of the Antarctic Circumpolar Current also extends the Antarctic winter sea ice edge far to the north, while regions with less steering allow the ice edge to shift back southwards; this pattern is strongly related to the observed pattern of decadal sea ice gain and retreat, respectively. Observed changes in CDW properties in the Ross/Amundsen/Bellingshausen Seas, from 1992 to 2011, suggest increased ventilation by the northern Deep Waters, which increases heat content in the upper ocean and freshens the abyssal layer. The increased ocean temperatures along the WAP affect sea ice extent and ice shelf mass loss.  The observed heat and sea ice changes are consistent with a strengthening of the southern ACC circulation and adjoining subpolar gyres.