Salinity response to atmospheric forcing of the Terra Nova Bay polynya, Antarctica

2021 ◽  
pp. 1-14
Author(s):  
Deborah A. Le Bel ◽  
Christopher J. Zappa ◽  
Giorgio Budillon ◽  
Arnold L. Gordon
Keyword(s):  
Ross Sea ◽  
Open Water ◽  
Heat Fluxes ◽  
Ice Formation ◽  
Atmospheric Forcing ◽  
Surface Heat Fluxes ◽  
Water Fraction ◽  
Salinity Response ◽  
Terra Nova Bay ◽  
Terra Nova

Abstract The density and salinity of High Salinity Shelf Water, a key component of Antarctic Bottom Water emanating from the Ross Sea, are intensified by brine rejection induced by ice formation within the Terra Nova Bay (TNB) polynya. Ocean mooring data from 2007, meteorological observations from automatic weather stations and a satellite-derived history of the opening of TNB polynya delineate variability in water column salinity linked to atmospheric forcing, with a period on the order of 10 days. Lagged correlation analysis indicates that on average salinity response lags the polynya opening by 2 days and the wind forcing by 5 days. We find stronger correlations of salinity with the wind during March through May and with the polynya open-water fraction during June through October, with decreasing lags in the latter period. A one-dimensional mixed-layer model incorporating thermodynamic ice formation captures the oscillations in salinity. A process study shows that the variability in the polynya open-water fraction governs the final salinity attained by the model as well as the salinity cycling. Variability in surface heat fluxes modulates that effect. Our work suggests that there is a more complex relationship between salinity, the polynya open-water fraction, and atmospheric forcing than previously suggested.

Surface heat fluxes and thermohaline variability in the Ross Sea and in Terra Nova Bay polynya

2009 ◽  
Vol 29 (15) ◽  
pp. 1887-1895 ◽  
Author(s):  
Giannetta Fusco ◽  
Giorgio Budillon ◽  
Giancarlo Spezie
Keyword(s):  
Ross Sea ◽  
Surface Heat ◽  
Heat Fluxes ◽  
Surface Heat Fluxes ◽  
Terra Nova Bay ◽  
Terra Nova

scholarly journals A comparison between polynya area and associated ice production with mooring-based measurements of temperature, salinity and currents in the southwestern Ross Sea, Antarctica

2011 ◽  
Vol 52 (57) ◽  
pp. 291-300 ◽  
Author(s):  
Stefan Kern ◽  
Stefano Aliani
Keyword(s):  
Ross Sea ◽  
Time Lag ◽  
Ice Formation ◽  
Terra Nova Bay ◽  
In Situ Observations ◽  
Satellite Microwave ◽  
Terra Nova ◽  
Ice Production ◽  
The Impact

AbstractWintertime (April–September) area estimates of the Terra Nova Bay polynya (TNBP), Antarctica, based on satellite microwave radiometry are compared with in situ observations of water salinity, temperature and currents at a mooring in Terra Nova Bay in 1996 and 1997. In 1996, polynya area anomalies and associated anomalies in polynya ice production are significantly correlated with salinity anomalies at the mooring. Salinity anomalies lag area and/or ice production anomalies by about 3 days. Up to 50% of the variability in the salinity at the mooring position can be explained by area and/or ice production anomalies in the TNBP for April–September 1996. This value increases to about 70% when considering shorter periods like April–June or May–July, but reduces to 30% later, for example July–September, together with a slight increase in time lag. In 1997, correlations are smaller, less significant and occur at a different time lag. Analysis of ocean currents at the mooring suggests that in 1996 conditions were more favourable than in 1997 for observing the impact of descending plumes of salt-enriched water formed in the polynya during ice formation on the water masses at the mooring depth.

Thermohaline structure and variability in the Terra Nova Bay polynya, Ross Sea

2000 ◽  
Vol 12 (4) ◽  
pp. 493-508 ◽  
Author(s):  
G. Budillon ◽  
G. Spezie
Keyword(s):  
Surface Layer ◽  
Cold Water ◽  
Ross Sea ◽  
Heat Budget ◽  
Salt Content ◽  
Heat Fluxes ◽  
Local Source ◽  
Near Surface ◽  
Terra Nova Bay ◽  
Terra Nova

Hydrological measurements from three cruises during the summers 1994/95, 1995/96 and 1997/98 in the western sector of the Ross Sea allow summer and year to year changes in heat and salt content in the Terra Nova Bay polynya to be analysed. Changes in the surface layer (upper pycnocline) followed the expected seasonal pattern of warming and freshening from the beginning to the end of the summer. These near-surface changes, expressed as net heating and salting rate, were about 11 W m−2 and -6 mg salt m−2 s−1. The heating changes were substantially lower than the estimated heat supplied by the atmosphere during the summer, which underlines the importance for this season of the advective component carried by the currents in the total heat budget. The year to year differences were about one or two orders of magnitude smaller than the seasonal changes in the surface layer. In the intermediate and deep layers, the summer heat and salt variability were of the same order as or one order higher than from one summer to the next. The differences in sign and magnitude for the heat change in the upper and in the lower pycnocline indicate a weak connection in the summer period between the surface heat fluxes and the deep waters. A local source of very cold water (with temperatures below the surface freezing point) of about 0.3 Sv has been detected close to the Terra Nova Bay coast. It arose out of the interaction of the shallow–intermediate layers of High Salinity Shelf Water with the coastal glaciers. The presence and the variability of this cold water point to the significant role of the thermohaline properties of Terra Nova Bay waters in controlling the floating glacier by governing the basal melting processes.

Upper ocean layer dynamics and response to atmospheric forcing in the Terra Nova Bay polynya, Antarctica

2010 ◽  
Vol 22 (3) ◽  
pp. 319-329 ◽  
Author(s):  
Andrea Cappelletti ◽  
Paola Picco ◽  
Tiziana Peluso
Keyword(s):  
Large Scale ◽  
Ross Sea ◽  
Meteorological Data ◽  
Surface Currents ◽  
Atmospheric Forcing ◽  
Concentration Data ◽  
Large Scale Circulation ◽  
Terra Nova Bay ◽  
Adcp Data ◽  
Terra Nova

AbstractA one-year time series of Acoustic Doppler Current Profiler (ADCP) data was collected in Terra Nova Bay (TNB) polynya (Ross Sea, Antarctica) during 2000. Together with Automatic Weather Station (AWS) Eneide meteorological data and Special Sensor Microwave Imager (SSM/I) ice concentration data, ADCP data were analysed to investigate upper layer dynamics and variability due to atmospheric forcing. Empirical Orthogonal Function (EOF) analysis was performed to separate the surface variability caused by local forcing from the large-scale circulation component. In particular, the first mode represented the barotropic circulation while the second the stronger surface currents. The decrease in shelf water density from melting sea ice resulted in an off-shore density gradient producing a southern shift in the circulation. This result proved to be consistent with the in situ data acquired during February–April at 120 m depth. The observed variability of the surface currents was assessed with respect to the thermal wind equation and the steady Ekman model. Strong katabatic winds shifted the surface currents eastward with respect to the general north-eastern circulation. The wind stress acted as a relevant forcing for the surface large-scale circulation in TNB, but had negligible effects on the vertically integrated transport.

Katabatic wind propagation over the western Ross Sea observed using ERS-1 scatterometer data

1997 ◽  
Vol 9 (2) ◽  
pp. 221-226 ◽  
Author(s):  
Gareth J. Marshall ◽  
John Turner
Keyword(s):  
Ross Sea ◽  
Coastal Region ◽  
Open Water ◽  
Katabatic Wind ◽  
Wind Fields ◽  
Atmospheric Flow ◽  
Terra Nova Bay ◽  
Pressure Centre ◽  
Terra Nova ◽  
Western Ross Sea

Wind fields derived from ERS-1 scatterometer data, acquired over the open water present in the western Ross Sea during the summer season, are used to study the patterns of mesoscale atmospheric flow connected with surges of katabatic air from the Terra Nova Bay convergence zone, located in the coastal region of Victoria Land. These katabatic winds may turn northward but also southward, or divide into separate northward- and southward-turning components; the latter situation is illustrated by a detailed case study. Analysis of concurrent AWS data, suggests that the most likely mechanism for the observed southward turning is the existence of a highly-localised low pressure centre south of Terra Nova Bay. Comparison of multitemporal ERS-1 scatterometer wind fields with AWS wind measurements demonstrate that the satellite data are: (i) able to correctly portray changes in mesoscale circulation patterns, and (ii) suitable for the routine monitoring of winds over open water around the Antarctic coastline, despite a less than ideal temporal coverage.

Particulate organic matter release below melting sea ice (Terra Nova Bay, Ross Sea, Antarctica): Possible relationships with zooplankton

2021 ◽  
pp. 103510
Author(s):  
Alessandro Cau ◽  
Claudia Ennas ◽  
Davide Moccia ◽  
Olga Mangoni ◽  
Francesco Bolinesi ◽  
...  
Keyword(s):  
Organic Matter ◽  
Sea Ice ◽  
Particulate Organic Matter ◽  
Ross Sea ◽  
Terra Nova Bay ◽  
Terra Nova

scholarly journals Diesel oil and PCB-degrading psychrotrophic bacteria isolated from Antarctic seawaters (Terra Nova Bay, Ross Sea)

2004 ◽  
Vol 23 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Maria De Domenico ◽  
Angelina Lo Giudice ◽  
Luigi Michaud ◽  
Marcello Saitta ◽  
Vivia Bruni
Keyword(s):  
Ross Sea ◽  
Diesel Oil ◽  
Psychrotrophic Bacteria ◽  
Terra Nova Bay ◽  
Terra Nova

scholarly journals Summer Epiphytic Diatoms from Terra Nova Bay and Cape Evans (Ross Sea, Antarctica) - A Synthesis and Final Conclusions

PLoS ONE ◽  
2016 ◽  
Vol 11 (4) ◽  
pp. e0153254 ◽  
Author(s):  
Roksana Majewska ◽  
Peter Convey ◽  
Mario De Stefano
Keyword(s):  
Ross Sea ◽  
Epiphytic Diatoms ◽  
Terra Nova Bay ◽  
Terra Nova

Significance of selected halocarbons monitoring in air samples collected in the Terra Nova Bay region (northern Victoria Land, Antarctica)

1999 ◽  
Vol 11 (2) ◽  
pp. 261-264 ◽  
Author(s):  
Filippo Mangani ◽  
Michela Maione ◽  
Luciano Lattanzi
Keyword(s):  
Ross Sea ◽  
Atmospheric Concentration ◽  
Air Samples ◽  
Terra Nova Bay ◽  
Victoria Land ◽  
Rate Of Increase ◽  
Terra Nova ◽  
Concentration Levels

CCl3F (or CFC-11) and CCl2F2 (or CFC-12) were determined in air samples collected, during subsequent summer Antarctic campaigns, in different sampling sites in the Ross Sea Region. The samples were analysed by GC-ECD after enrichment. Data obtained since 1988–89 were plotted to observe the trend of CFCs atmospheric concentration levels. A decrease in the rate of increase of CFC-12 concentration was observed, whilst the concentration of CFC-11 was actually seen to be decreasing.

Shallow-water benthic hydroids from Tethys Bay (Terra Nova Bay, Ross Sea, Antarctica)

Polar Biology ◽  
2013 ◽  
Vol 36 (5) ◽  
pp. 731-753 ◽  
Author(s):  
Álvaro L. Peña Cantero ◽  
Ferdinando Boero ◽  
Stefano Piraino
Keyword(s):  
Shallow Water ◽  
Ross Sea ◽  
Terra Nova Bay ◽  
Terra Nova
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