Large-Scale Circulation Features in the Central and Western Ross Sea (Antarctica)

Abstract

Circulation patterns in the central-western part of the Ross Sea were inferred from CTD casts, ADCP profiles and from a 1-year recording of currents, temperatures and salinities from moorings deployed from February 1995 to January 1996 in the framework of the Italian National Program of Antarctic Research (PNRA). The spreading paths of two important water masses produced in the Ross Sea were also studied. Ice Shelf Water (ISW) was found outflowing from beneath the Ross Ice Shelf at 177°W, with two preferential directions, westward and northward. The northward flow of ISW in the Challenger Basin was not observed beyond 76°S. The High Salinity Shelf Water (HSSW) found in Terra Nova Bay was mainly flowing in the northeast direction along the coast, but a significant southward flow was detected by currentmeters during November. Bathymetric constraints were significant for spreading of the continental shelf water masses. The seasonal temperature and salinity cycle due to ice formation and melting processes was detected in all the recorded time series at depths around 250 m, but does not seem to affect in a significant way the local circulation, as indicated from currentmeter records.