SUSPENDED MATTER VARIABILITY IN RELATION TO WATER MASSES IN TERRA NOVA BAY (ROSS SEA—ANTARCTICA)

The concentration (total particulate matter, TPM) and size of particulate matter collected during three oceanographic cruises carried out in the Ross Sea (Antarctica) in the frame of the Climatic Long-Term Interactions for the Mass- Balance in Antarctica (CLIMA) Project have been analysed in relation to the characteristics of the water masses present in the polynya of Terra Nova Bay (TNB). The water column was divisible into three layers: the surficial, which included the Antarctic Surface Waters (AASW); the intermediate, which sometimes included the Terra Nova Ice Shelf Waters (TISW); and the bottom, mainly consisting of High Salinity Shelf Waters (HSSW). The highest TPM concentrations were observed in the AASW, where the largest particles were also found; the lowest TPM concentrations were found in the bottom waters (HSSW). The TPM concentrations found in the water samples collected in the 1998 austral summer were almost twice as high as those found in 2001. In contrast, there was no difference in the size of the particles collected in 1998 and 2001, but there was a notable difference between those found in 1998 and 2001 and those found in 1997. The particulate input in the polynya waters is mainly related to ice melting processes and the variability in the TISW coming from the Nansen Ice Sheet and Drygalski and Campbell Ice Tongues.