Investigations of sea ice-ocean interaction on the continental shelf in the southwestern Weddell Sea reveal a strong correlation between fluctuations of atmospheric forcing and sea ice formation. Anomalies of meridional wind stress in the inner Weddell Sea are consistent with the phase of the Antarctic Circumpolar Wave. Positive anomalies of northward wind stress cause an increase of sea ice export in the same year and of sea ice formation in the following year, leading to an increased production of High-Salinity Shelf Water. Driven by a varying zonal density distribution over the continental shelf, the circulation in the Filchner-Ronne Ice Shelf cavity fluctuates between two modes, each of which features a characteristic distribution of basal freezing and melting regions. Thus signals of interannual atmospheric variability propagate into the deep ocean and the sub-ice shelf cavities.