News & Events

ATOC seminar: Changes in Southern Ocean temperature and salinity: A view from Argo floats

Friday, March 09, 2018, 3:00PM - 4:00PM


Donata Giglio

Scripps Institution of Oceanography


SEEC Auditorium (room C120)

4001 Discovery Drive, Boulder

Argo profiling floats initiated a revolution in observational physical oceanography by providing numerous, high-quality, global, year-round, in situ (0–2000 dbar) temperature and salinity observations. Temperature and salinity changes in the global ocean reveal corresponding changes in circulation, air-sea fluxes, and steric sea level, and hence are key to understanding how the earth system is evolving. Peak warming has been observed in the Southern Ocean in recent decades. Here, variations in temperature and salinity in the Southern Ocean equatorward of 60°S are quantified in the context of the Antarctic Circumpolar Current (ACC). Circumpolar regions of strong gradients in water mass properties (i.e. fronts) are observed in the Southern ocean, particularly within the ACC, and are associated with a strong horizontal flow. This study uses Argo’s unprecedented sampling of the Southern Ocean to describe the time-mean position of the ACC’s Subantarctic and Polar Fronts, comparing and contrasting two different methods for locating fronts using the same dataset. Temperature and salinity changes are investigated in regions in between fronts. These variations are described during 2006–13, as integrated heat and freshwater changes, along with the role of wind driven vertical advection.


Free and open to the public.