Part of the UK contribution to the SASSI project (led by Karen Heywood), involved investigating the temperature and salinity variability on the Antarctic continental shelf and slope in the southeastern Weddell Sea.
Five moorings were deployed in the southeastern Weddell Sea for one year, between Feb 2009 and Feb 2010. The year-long timeseries of observations allows us to determine processes responsible for seasonal variability in the region. These results are detailed in Graham et al. (2013, J Geophys Res).
Some key results include:
- The seasonal cycle in salinity shows freshening during Autumn, with the stongest signal seen on the shelf (approx. 250 m).
- Freshening begins during strong along-shore winds in late April 2009.
- Ekman transport and mixing will both contribute to freshening on the shelf.
- Comparison with a model simulation shows that importance of along-shore advection.
- Advection of fresh water from upstream determines the timing of the salinity minimum at the array.
- Transport of the Antarctic Slope Current has a maximum during late April.
- Rapid fluctuations in temperature and salinity are associated with shoaling/deepening of the pycnocline. This is linked to wind stress variability over the array.