Thermohaline Data and Océan Circulation on the
Ross Sea Continental Shelf
S.S. Jacobs and C.F. Giulivi
Lamont-Doherty Earth Observatory of Columbia University, Palisades,
New York 10964, USA
Abstract
The océan station data base on the Ross Sea continental shelf includes measurements from more than fifty cruises, and a few observations through ice holes.
Using représentative salinity and température transects from the summers of
1962-63, 1976-77 and 1983-84, we briefly review the océan stratification and circulation, identifying five primary water masses. Year-round salinity profiles at a
single location in 1960-61 and early winter température profiles along the dateline
in 1995 are discussed in relation to anticipated seasonal changes. A strong zonal
salinity gradient and substantial différences between two représentations of the
shelf data base reveal the need for caution in modelling and bottom water investigations. Long term observations of shelf water salinity and studies of the inflow
of modified deep water would help in the évaluation of recent evidence for
marked interannual and decadal variability on the continental shelf.
1 Introduction
Analyses of historical océan température and salinity measurements on the
Antarctic continental shelf require a careful considération of original sources,
data processing, and variability in space and time. The effects of stronger winter
forcing must be inferred from predominantly late summer observations.
Considérable variability over small distances can influence the choice of areas
over which data can be meaningfully averaged. Lengthening time sériés display
substantial variability on interannual and longer temporal scales. Here we revisit
these caveats in the context of the increasing utilization of gridded, archived data
for modelling and climate change work. Available océan station data on the Ross
Sea continental shelf are summarized, and some différences that can arise from
alternate treatments of a similar database are illustrated. We also evaluate a vénérable set of year-long salinity profiles, and a transect of recent May température
measurements.
The région north of the Ross Ice Shelf is better sampled than most of the
remaining circumpolar continental shelf, thanks to a minimal sea ice cover during the austral summer and a location adjacent to McMurdo Station and other
Antarctic bases. Aspects of its océan circulation hâve been described in numerous
papers (e.g., [1-14]) and the references therein. Here we présent a comparable set
Ross Sea Continental Shelf
S.S. Jacobs and C.F. Giulivi
Lamont-Doherty Earth Observatory of Columbia University, Palisades,
New York 10964, USA
Abstract
The océan station data base on the Ross Sea continental shelf includes measurements from more than fifty cruises, and a few observations through ice holes.
Using représentative salinity and température transects from the summers of
1962-63, 1976-77 and 1983-84, we briefly review the océan stratification and circulation, identifying five primary water masses. Year-round salinity profiles at a
single location in 1960-61 and early winter température profiles along the dateline
in 1995 are discussed in relation to anticipated seasonal changes. A strong zonal
salinity gradient and substantial différences between two représentations of the
shelf data base reveal the need for caution in modelling and bottom water investigations. Long term observations of shelf water salinity and studies of the inflow
of modified deep water would help in the évaluation of recent evidence for
marked interannual and decadal variability on the continental shelf.
1 Introduction
Analyses of historical océan température and salinity measurements on the
Antarctic continental shelf require a careful considération of original sources,
data processing, and variability in space and time. The effects of stronger winter
forcing must be inferred from predominantly late summer observations.
Considérable variability over small distances can influence the choice of areas
over which data can be meaningfully averaged. Lengthening time sériés display
substantial variability on interannual and longer temporal scales. Here we revisit
these caveats in the context of the increasing utilization of gridded, archived data
for modelling and climate change work. Available océan station data on the Ross
Sea continental shelf are summarized, and some différences that can arise from
alternate treatments of a similar database are illustrated. We also evaluate a vénérable set of year-long salinity profiles, and a transect of recent May température
measurements.
The région north of the Ross Ice Shelf is better sampled than most of the
remaining circumpolar continental shelf, thanks to a minimal sea ice cover during the austral summer and a location adjacent to McMurdo Station and other
Antarctic bases. Aspects of its océan circulation hâve been described in numerous
papers (e.g., [1-14]) and the references therein. Here we présent a comparable set