Haid, Verena, Timmermann, Ralph, Ebner, Lars and Heinemann, Günther (2015) Atmospheric forcing of coastal polynyas in the south-western Weddell Sea. Antarctic Science, 27 (4). pp. 388-402. DOI 10.1017/S0954102014000893.

Text Haid.pdf - Published Version Restricted to Registered users only Download (2MB) | Contact

Abstract

The development of coastal polynyas, areas of enhanced heat flux and sea ice production
strongly depend on atmospheric conditions. In Antarctica, measurements are scarce and models are
essential for the investigation of polynyas. A robust quantification of polynya exchange processes in
simulations relies on a realistic representation of atmospheric conditions in the forcing dataset. The
sensitivity of simulated coastal polynyas in the south-western Weddell Sea to the atmospheric forcing is
investigated with the Finite-Element Sea ice-Ocean Model (FESOM) using daily NCEP/NCAR
reanalysis data (NCEP), 6 hourly Global Model Europe (GME) data and two different hourly datasets
from the high-resolution Consortium for Small-Scale Modelling (COSMO) model. Results are
compared for April to August in 2007–09. The two coarse-scale datasets often produce the extremes
of the data range, while the finer-scale forcings yield results closer to the median. The GME experiment
features the strongest winds and, therefore, the greatest polynya activity, especially over the eastern
continental shelf. This results in higher volume and export of High Salinity Shelf Water than in the
NCEP and COSMO runs. The largest discrepancies between simulations occur for 2008, probably due
to differing representations of the ENSO pattern at high southern latitudes. The results suggest that the
large-scale wind field is of primary importance for polynya development.

Actions (login required)

View Item