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

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.

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Thermal, pressure and wind fields at ground level in the area of the Italian base at Terra Nova Bay, Victoria Land, Antarctica, as observed by a network of automatic weather stations

Annales Geophysicae ◽

10.1007/s00585-996-1088-1 ◽

1996 ◽

Vol 14 (10) ◽

pp. 1088-1094 ◽

Cited By ~ 1

Author(s):

E. Cogliani ◽

G. Abbate ◽

S. Racalbuto

Keyword(s):

Wind Speed ◽

Coastal Region ◽

Ground Level ◽

Katabatic Wind ◽

Wind Fields ◽

The North ◽

Terra Nova Bay ◽

Spatial Configurations ◽

Weather Stations ◽

Terra Nova

Abstract. Ground temperature, pressure and wind speed monthly averages in the area of the Italian Station at Terra Nova Bay, Antarctica, were analyzed for the period 1987–1991 by means of a network of nine AWS (automatic weather stations). Spatial configurations of temperature show a well-defined, relatively warm island in the area of Terra Nova Bay, between Drygalsky and Campbell ice tongues, throughout the year. A second warm island is present to the north along the coast, between Aviator and Mariner ice tongues, for most of the year. From February to March a rapid drop in temperature is observed at all stations. A strong thermal gradient develops during February, March, April and October, November, December, between the coastal region and inner highlands. The baric configuration follows the elevation of the area. Annual average pressure and temperature as functions of stations altitude show linear trends. Severe katabatic wind episodes are recorded at all stations, with wind speed exceeding 25 m s–1 and direction following the orographic features of the inner areas. Co-occurrences of these episodes were observed for stations located along stream lines of cold air drainage. The autocorrelation function of maximum wind speed time series shows wind persistence of 2–3 days and wind periodicity of about one week.

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Variability in high-salinity shelf water production in the Terra Nova Bay polynya, Antarctica

Ocean Science ◽

10.5194/os-16-373-2020 ◽

2020 ◽

Vol 16 (2) ◽

pp. 373-388 ◽

Cited By ~ 1

Author(s):

Seung-Tae Yoon ◽

Won Sang Lee ◽

Craig Stevens ◽

Stefan Jendersie ◽

SungHyun Nam ◽

...

Keyword(s):

High Salinity ◽

Ross Sea ◽

Coastal Region ◽

Shelf Water ◽

Antarctic Bottom Water ◽

Ice Shelf ◽

Terra Nova Bay ◽

Salinity Variability ◽

Salinity Increase ◽

Terra Nova

Abstract. Terra Nova Bay in Antarctica is a formation region for high-salinity shelf water (HSSW), which is a major source of Antarctic Bottom Water. Here, we analyze spatiotemporal salinity variability in Terra Nova Bay with implications for the local HSSW production. The salinity variations in the Drygalski Basin and eastern Terra Nova Bay near Crary Bank in the Ross Sea were investigated by analyzing hydrographic data from instrumented moorings, vessel-based profiles, and available wind and sea-ice products. Near-bed salinity in the eastern Terra Nova Bay (∼660 m) and Drygalski Basin (∼1200 m) increases each year beginning in September. Significant salinity increases (>0.04) were observed in 2016 and 2017, which is likely related to active HSSW formation. According to velocity data at identical depths, the salinity increase from September was primarily due to advection of the HSSW originating from the coastal region of the Nansen Ice Shelf. In addition, we show that HSSW can also be formed locally in the upper water column (<300 m) of the eastern Terra Nova Bay through convection supplied by brine from the surface, which is related to polynya development via winds and ice freezing. While the general consensus is that the salinity of the HSSW was decreasing from 1995 to the late 2000s in the region, the salinity has been increasing since 2016. In 2018, it returned to values comparable to those in the early 2000s.

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

Antarctic Science ◽

10.1017/s0954102021000146 ◽

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.

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Spatio-temporal variations in High-Salinity Shelf Water production in Terra Nova Bay polynya, Antarctica

10.5194/os-2019-80 ◽

2019 ◽

Author(s):

Seung-Tae Yoon ◽

Won Sang Lee ◽

Craig Stevens ◽

Stefan Jendersie ◽

SungHyun Nam ◽

...

Keyword(s):

High Salinity ◽

Ross Sea ◽

Coastal Region ◽

Deep Ocean ◽

Temporal Variations ◽

Shelf Water ◽

Terra Nova Bay ◽

Salinity Increase ◽

Terra Nova ◽

Spatio Temporal

Abstract. The formation of High-Salinity Shelf Water (HSSW), which is the major source of Antarctic bottom water (AABW), has been observed in Terra Nova Bay (TNB) in Antarctica. We believe a description of the spatio-temporal variation of salinity in TNB would help understand the production of HSSW in the region. Hence, the aim of this study is to investigate salinity variations in the Drygalski Basin (DB) and eastern TNB close to Crary Bank of the Ross Sea. For this, we use the moored and profiled hydrographic data, as well as available wind and sea-ice products. We found that deep-ocean salinity in the eastern TNB (~ 660 m) and DB (~ 1200 m) increases each year starting in September, and large amounts of salinity increase (> 0.04) were observed in 2016 and 2017. According to the velocity data observed at the same depths, the increases in salinity from September were due to the advection of HSSW from the coastal region of the Nansen ice shelf (NIS). The significant increases in salinity are related to the formation of active HSSW, evidence of which can be found from the HSSW properties obtained in February 2017 and March 2018. In addition, we show that HSSW can locally formed in the upper layer (

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Occurrence of Mysidacea (Crustacea) in the Pacific Sector of Antarctica and Distribution of Antarctomysis ohlini in Terra Nova Bay (Western Ross Sea)

Ross Sea Ecology ◽

10.1007/978-3-642-59607-0_26 ◽

2000 ◽

pp. 335-350

Author(s):

N. Crescenti ◽

L. Guglielmo ◽

G. Costanzo ◽

G. Zagami ◽

A. Granata

Keyword(s):

Ross Sea ◽

Terra Nova Bay ◽

The Pacific ◽

Terra Nova ◽

Western Ross Sea

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The Atmospheric Boundary Layer and Surface Conditions during Katabatic Wind Events over the Terra Nova Bay Polynya

Remote Sensing ◽

10.3390/rs12244160 ◽

2020 ◽

Vol 12 (24) ◽

pp. 4160

Author(s):

Marta Wenta ◽

John J. Cassano

Keyword(s):

Open Water ◽

Unmanned Aircraft ◽

Katabatic Wind ◽

Katabatic Winds ◽

Surface Conditions ◽

Terra Nova Bay ◽

Coastal Polynya ◽

Terra Nova ◽

Wind Events ◽

Aircraft System

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.

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Frazil ice growth and production during katabatic wind events in the Ross Sea, Antarctica

10.5194/tc-2019-213 ◽

2019 ◽

Author(s):

Lisa De Pace ◽

Madison Smith ◽

Jim Thomson ◽

Sharon Stammerjohn ◽

Steve Ackley ◽

...

Keyword(s):

Ross Sea ◽

Vertical Mixing ◽

Katabatic Wind ◽

Frazil Ice ◽

Wind Speeds ◽

Terra Nova Bay ◽

Air Temperatures ◽

Terra Nova ◽

Wind Events ◽

Ice Production

Abstract. During katabatic wind events in the Terra Nova Bay and Ross Sea polynyas, wind speeds exceeded 20 m s−1, air temperatures were below −25 ℃, and the mixed layer extended as deep as 600 meters. Yet, upper ocean temperature and salinity profiles were not perfectly homogeneous, as would be expected with vigorous convective heat loss. Instead, the profiles revealed bulges of warm and salty water directly beneath the ocean surface and extending downwards tens of meters. Considering both the colder air above and colder water below, we suggest the increase in temperature and salinity reflects latent heat and salt release during unconsolidated frazil ice production within the upper water column. We use a simplified salt budget to analyze these anomalies to estimate in-situ frazil ice concentration between 332 × 10−3 and 24.4 × 10−3 kg m−3. Contemporaneous estimates of vertical mixing by turbulent kinetic energy dissipation reveal rapid convection in these unstable density profiles, and mixing lifetimes from 2 to 12 minutes. The corresponding median rate of ice production is 26 cm day−1 and compares well with previous empirical and model estimates. Our individual estimates of ice production up to 378 cm day−1 reveal the intensity of short-term ice production events during the windiest episodes of our occupation of Terra Nova Bay Polynya.

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

Journal of Marine Systems ◽

10.1016/j.jmarsys.2021.103510 ◽

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

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

Annals of Glaciology ◽

10.3189/172756411795931705 ◽

2011 ◽

Vol 52 (57) ◽

pp. 291-300 ◽

Cited By ~ 3

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.

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