scholarly journals Inside Katabatic Winds over the Terra Nova Bay PolynyaPart 1: Atmospheric Jet and Surface Conditions

Author(s):  
P. S. Guest
2020 ◽  
Vol 12 (24) ◽  
pp. 4160
Author(s):  
Marta Wenta ◽  
John J. Cassano

Off the coast of Victoria Land, Antarctica an area of open water—the Terra Nova Bay Polynya (TNBP)—persists throughout the austral winter. The development of this coastal polynya is driven by extreme katabatic winds blowing down the slopes of Transantarctic Mountains. The surface-atmosphere coupling and ABL transformation during the katabatic wind events between 18 and 25 September 2012 in Terra Nova Bay are studied, using observations from Aerosonde unmanned aircraft system (UAS), numerical modeling results and Antarctic Weather Station (AWS) measurements. First, we analyze how the persistence and strength of the katabatic winds relate to sea level pressure (SLP) changes in the region throughout the studied period. Secondly, the polynya extent variations are analysed in relation to wind speed changes. We conclude that the intensity of the flow, surface conditions in the bay and regional SLP fluctuations are all interconnected and contribute to polynya development. We also analyse the Antarctic Mesoscale Prediction System (AMPS) forecast for the studied period and find out that incorrect representation of vertical ABL properties over the TNBP might be caused by overestimated sea ice concentrations (SIC) used as model input. Altogether, this research provides a unique description of TNBP development and its interactions with the atmosphere and katabatic winds.


Polar Record ◽  
1982 ◽  
Vol 21 (131) ◽  
pp. 137-146 ◽  
Author(s):  
David H. Bromwich ◽  
Dennis D. Kurtz

The six men of Captain Robert Falcon Scott's Northern Party were stranded on Inexpressible Island (Fig 1) from late February to September 1912. During that period their lives were profoundly influenced by prevailing surface wind and sea ice conditions in Terra Nova Bay. Members of the party lived under the most primitive conditions, enduring more than seven months of strong, persistent winds. The western part of Terra Nova Bay remained largely free of ice in 1912, thus preventing the group from leaving until there was sufficient daylight to cross the Drygalski Ice Tongue. This open water, however, may also have assured their survival for it attracted enough seals and penguins to provide them with a continual though limited supply of food. Despite these adverse conditions some of the men, Raymond Priestley in particular, kept detailed journals which provide the only in situwintertime observations for this area. Analysis of Priestley's wind and ice record provides strong confirmation of our model for the wintertime persistence of open water (a polynya) in Terra Nova Bay.


2021 ◽  
pp. 103510
Author(s):  
Alessandro Cau ◽  
Claudia Ennas ◽  
Davide Moccia ◽  
Olga Mangoni ◽  
Francesco Bolinesi ◽  
...  

2011 ◽  
Vol 52 (57) ◽  
pp. 291-300 ◽  
Author(s):  
Stefan Kern ◽  
Stefano Aliani

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.


2004 ◽  
Vol 23 (2) ◽  
pp. 141-146 ◽  
Author(s):  
Maria De Domenico ◽  
Angelina Lo Giudice ◽  
Luigi Michaud ◽  
Marcello Saitta ◽  
Vivia Bruni

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