Southern Ocean

By connecting the deep ocean reservoir of carbon and heat to the atmosphere, the Southern Ocean is a primary climate regulator. A readily observed component of regulation is the sea ice cover, which provides insulation and affects albedo. As noted in Section 6f, 2016 showed a spectacular decline late in the year, with the lowest ever recorded spring sea ice cover (see Fig. 6.8a). The upper ocean experienced large temperature anomalies consistent with the sea ice patterns discussed in Section 6f (Figs. 6.10b,c). In addition, the open-ocean polynya observed over Maud Rise in August (e.g., see Fig. 6.8c) was likely driven by unusually weak haline stratification (Fig. 6.10f). Observed salinity changes suggest cryospheric influences on multiyear time scales.