Winter Atmospheric Forcing of the Ross Sea Polynya

Author(s):  
David Bromwich ◽  
Zhong Liu ◽  
Aric N. Rogers ◽  
Michael L. Van Woert
Keyword(s):  
Ross Sea ◽  
2021 ◽  
pp. 1-14
Author(s):  
Deborah A. Le Bel ◽  
Christopher J. Zappa ◽  
Giorgio Budillon ◽  
Arnold L. Gordon

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.


2010 ◽  
Vol 22 (3) ◽  
pp. 319-329 ◽  
Author(s):  
Andrea Cappelletti ◽  
Paola Picco ◽  
Tiziana Peluso

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.


2012 ◽  
Vol 62 (5) ◽  
pp. 701-723 ◽  
Author(s):  
Pierre Mathiot ◽  
Nicolas C. Jourdain ◽  
Bernard Barnier ◽  
Hubert Gallée ◽  
Jean Marc Molines ◽  
...  

2020 ◽  
Vol 636 ◽  
pp. 189-205
Author(s):  
A Lescroël ◽  
PO’B Lyver ◽  
D Jongsomjit ◽  
S Veloz ◽  
KM Dugger ◽  
...  

Inter-individual differences in demographic traits of iteroparous species can arise through learning and maturation, as well as from permanent differences in individual ‘quality’ and sex-specific constraints. As the ability to acquire energy determines the resources an individual can allocate to reproduction and self-maintenance, foraging behavior is a key trait to study to better understand the mechanisms underlying these differences. So far, most seabird studies have focused on the effect of maturation and learning processes on foraging performance, while only a few have included measures of individual quality. Here, we investigated the effects of age, breeding experience, sex, and individual breeding quality on the foraging behavior and location of 83 known-age Adélie penguins at Cape Bird, Ross Sea, Antarctica. Over a 2 yr period, we showed that (1) high-quality birds dived deeper than lower quality ones, apparently catching a higher number of prey per dive and targeting different foraging locations; (2) females performed longer foraging trips and a higher number of dives compared to males; (3) there were no significant age-related differences in foraging behavior; and (4) breeding experience had a weak influence on foraging behavior. We suggest that high-quality individuals have higher physiological ability, enabling them to dive deeper and forage more effectively. Further inquiry should focus on determining the physiological differences among penguins of different quality.


2006 ◽  
Vol 2 (2) ◽  
pp. 51-63 ◽  
Author(s):  
Patrick T. Maher ◽  
Alison J. McIntosh ◽  
Gary D. Steel
Keyword(s):  

2013 ◽  
Author(s):  
E. J. Metzger ◽  
Alan J. Wallcraft ◽  
Pamela G. Posey ◽  
Ole M. Smedstad ◽  
Deborah S. Franklin
Keyword(s):  

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