Observations of cetaceans in the south-east Atlantic sector of the Southern Ocean, during summer 2008

Polar Biology ◽  
2014 ◽  
Vol 37 (6) ◽  
pp. 891-895
Author(s):  
L. Nøttestad ◽  
B. A. Krafft ◽  
H. Søiland ◽  
G. Skaret
Keyword(s):  
Southern Ocean ◽  
The South ◽  
East Atlantic ◽  
Atlantic Sector

Ice-rafted volcanic ash in the South Atlantic sector of the Southern Ocean during the last 100,000 years

1983 ◽  
Vol 53 (4) ◽  
pp. 291-312 ◽  
Author(s):  
David G Smith ◽  
Michael T Ledbetter ◽  
Paul F Ciesielski
Keyword(s):  
Southern Ocean ◽  
Volcanic Ash ◽  
South Atlantic ◽  
The South ◽  
Atlantic Sector

Mesozooplankton biomass distribution in the upper 100 m layer of the Atlantic sector of the Southern Ocean

1996 ◽  
Vol 8 (4) ◽  
pp. 343-348 ◽  
Author(s):  
Jury A. Rudjakov
Keyword(s):  
Southern Ocean ◽  
Size Range ◽  
South Atlantic ◽  
Biomass Distribution ◽  
The South ◽  
Atlantic Sector ◽  
Data Centre ◽  
Mesozooplankton Biomass ◽  
Wet Weight ◽  
Oceanographic Data

The distribution of annual mean biomass of mesozooplankton (animals in the size range 0.2–20 mm) in the upper layer (0–100 m) of the Atlantic sector of the Southern Ocean was mapped. The map was constructed from 4216 measurements at 2184 oceanographic stations, from the Russian and Brazilian archive records, from published sources, and from the British Oceanographic Data Centre. The annual mean mesozooplankton biomass value for the South Atlantic is estimated in this study to be 93 mg m−3 wet weight.

Abrupt Cooling of Antarctic Surface Waters and Sea Ice Expansion in the South Atlantic Sector of the Southern Ocean at 5000 cal yr B.P.

2001 ◽  
Vol 56 (2) ◽  
pp. 191-198 ◽  
Author(s):  
David A. Hodell ◽  
Sharon L. Kanfoush ◽  
Aldo Shemesh ◽  
Xavier Crosta ◽  
Christopher D. Charles ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Sea Ice ◽  
Surface Waters ◽  
Climate Changes ◽  
Ice Core ◽  
South Atlantic ◽  
The South ◽  
Atlantic Sector ◽  
Middle Holocene ◽  
The North

AbstractAntarctic surface waters were warm and ice free between 10,000 and 5000 cal yr B.P., as judged from ice-rafted debris and microfossils in a piston core at 53°S in the South Atlantic. This evidence shows that about 5000 cal yr B.P., sea surface temperatures cooled, sea ice advanced, and the delivery of ice-rafted detritus (IRD) to the subantarctic South Atlantic increased abruptly. These changes mark the end of the Hypsithermal and onset of Neoglacial conditions. They coincide with an early Neoglacial advance of mountain glaciers in South America and New Zealand between 5400 and 4900 cal yr B.P., rapid middle Holocene climate changes inferred from the Taylor Dome Ice Core (Antarctica), cooling and increased IRD in the North Atlantic, and the end of the African humid period. The near synchrony and abruptness of all these climate changes suggest links among the tropics and both poles that involved nonlinear response to gradual changes in Northern Hemisphere insolation. Sea ice expansion in the Southern Ocean may have provided positive feedback that hastened the end of the Hypsithermal and African humid periods in the middle Holocene.

scholarly journals Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene

2018 ◽  
Author(s):  
Zoë Thomas ◽  
Richard T. Jones ◽  
Chris Fogwill ◽  
Jackie Hatton ◽  
Alan Williams ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Late Holocene ◽  
Ice Core ◽  
South Atlantic ◽  
Falkland Islands ◽  
The South ◽  
Pressure System ◽  
Amundsen Sea ◽  
Atlantic Sector ◽  
Synoptic Conditions

Abstract. The Amundsen Sea Low (ASL) plays a major role in modulating the climate and environment of Antarctica and is of global importance in the Earth system. Unfortunately, a relative dearth of observational data across the Amundsen and Bellingshausen Seas prior to the satellite era (post-1979) limits our understanding of past behaviour and impact of the ASL. The limited proxy evidence for changes in the ASL are primarily limited to the Antarctic where ice core evidence suggests a deepening of the atmospheric pressure system during the late Holocene. However, no data has previously been reported from the northern side of the ASL. Here we report a high-resolution, multi-proxy study of a 5000 year-long peat record from the Falkland Islands (South Atlantic sector of the Southern Ocean), an area sensitive to contemporary ASL dynamics. In combination with climate reanalysis, we find a marked period of wetter, colder conditions most likely the result of enhanced southerly airflow between 5000 and 2500 years ago, and inconsistent with synoptic conditions associated with the ASL today. After 2500 years ago, drier and warmer conditions were established, implying more westerly airflow and the increased projection of the ASL onto the South Atlantic. Our results are in agreement with Antarctic ice core records and suggest the Falkland Islands provide a valuable location for reconstructing atmospheric circulation changes across a large sector of the Southern Ocean on multi-decadal to millennial timescales. The possible role of tropical Pacific in establishing contemporary-like synoptic circulation is explored.

scholarly journals The influence of environmental variability on the biogeography of coccolithophores and diatoms in the Great Calcite Belt

2017 ◽  
Vol 14 (21) ◽  
pp. 4905-4925 ◽  
Author(s):  
Helen E. K. Smith ◽  
Alex J. Poulton ◽  
Rebecca Garley ◽  
Jason Hopkins ◽  
Laura C. Lubelczyk ◽  
...  
Keyword(s):  
Species Composition ◽  
Southern Ocean ◽  
Silicic Acid ◽  
Mixed Layer ◽  
Dissolved Inorganic Carbon ◽  
Emiliania Huxleyi ◽  
The South ◽  
Carbonate Chemistry ◽  
Atlantic Sector ◽  
South Indian

Abstract. The Great Calcite Belt (GCB) of the Southern Ocean is a region of elevated summertime upper ocean calcite concentration derived from coccolithophores, despite the region being known for its diatom predominance. The overlap of two major phytoplankton groups, coccolithophores and diatoms, in the dynamic frontal systems characteristic of this region provides an ideal setting to study environmental influences on the distribution of different species within these taxonomic groups. Samples for phytoplankton enumeration were collected from the upper mixed layer (30 m) during two cruises, the first to the South Atlantic sector (January–February 2011; 60° W–15° E and 36–60° S) and the second in the South Indian sector (February–March 2012; 40–120° E and 36–60° S). The species composition of coccolithophores and diatoms was examined using scanning electron microscopy at 27 stations across the Subtropical, Polar, and Subantarctic fronts. The influence of environmental parameters, such as sea surface temperature (SST), salinity, carbonate chemistry (pH, partial pressure of CO2 (pCO2), alkalinity, dissolved inorganic carbon), macronutrients (nitrate + nitrite, phosphate, silicic acid, ammonia), and mixed layer average irradiance, on species composition across the GCB was assessed statistically. Nanophytoplankton (cells 2–20 µm) were the numerically abundant size group of biomineralizing phytoplankton across the GCB, with the coccolithophore Emiliania huxleyi and diatoms Fragilariopsis nana, F. pseudonana, and Pseudo-nitzschia spp. as the most numerically dominant and widely distributed. A combination of SST, macronutrient concentrations, and pCO2 provided the best statistical descriptors of the biogeographic variability in biomineralizing species composition between stations. Emiliania huxleyi occurred in silicic acid-depleted waters between the Subantarctic Front and the Polar Front, a favorable environment for this species after spring diatom blooms remove silicic acid. Multivariate statistics identified a combination of carbonate chemistry and macronutrients, covarying with temperature, as the dominant drivers of biomineralizing nanoplankton in the GCB sector of the Southern Ocean.

Biomass and energy transfer to baleen whales in the South Atlantic sector of the Southern Ocean

2004 ◽  
Vol 51 (12-13) ◽  
pp. 1397-1409 ◽  
Author(s):  
S REILLY ◽  
S HEDLEY ◽  
J BORBERG ◽  
R HEWITT ◽  
D THIELE ◽  
...  
Keyword(s):  
Energy Transfer ◽  
Southern Ocean ◽  
South Atlantic ◽  
The South ◽  
Atlantic Sector ◽  
Baleen Whales

scholarly journals Evidence for increased expression of the Amundsen Sea Low over the South Atlantic during the late Holocene

2018 ◽  
Vol 14 (11) ◽  
pp. 1727-1738 ◽  
Author(s):  
Zoë A. Thomas ◽  
Richard T. Jones ◽  
Chris J. Fogwill ◽  
Jackie Hatton ◽  
Alan N. Williams ◽  
...  
Keyword(s):  
Southern Ocean ◽  
Late Holocene ◽  
Ice Core ◽  
South Atlantic ◽  
Falkland Islands ◽  
The South ◽  
Pressure System ◽  
Amundsen Sea ◽  
Atlantic Sector ◽  
Concentration Changes

Abstract. The Amundsen Sea Low (ASL) plays a major role in the climate and environment of Antarctica and the Southern Ocean, including surface air temperature and sea ice concentration changes. Unfortunately, a relative dearth of observational data across the Amundsen and Bellingshausen seas prior to the satellite era (post-1979) limits our understanding of the past behaviour and impact of the ASL. The limited proxy evidence for changes in the ASL are primarily restricted to the Antarctic where ice core evidence suggests a deepening of the atmospheric pressure system during the late Holocene. However, no data have previously been reported from the northern side of the ASL. Here we report a high-resolution, multi-proxy study of a 5000-year-long peat record from the Falkland Islands, a location sensitive to contemporary ASL dynamics which modulates northerly and westerly airflow across the southwestern South Atlantic sector of the Southern Ocean. In combination with climate reanalysis, we find a marked period of wetter, colder conditions most likely the result of enhanced southerly airflow between 5000 and 2500 years ago, suggesting limited ASL influence over the region. After 2500 years ago, drier and warmer conditions were established, implying more westerly airflow and the increased projection of the ASL onto the South Atlantic. The possible role of the equatorial Pacific via atmospheric teleconnections in driving this change is discussed. Our results are in agreement with Antarctic ice core records and fjord sediments from the southern South American coast, and suggest that the Falkland Islands provide a valuable location for reconstructing high southern latitude atmospheric circulation changes on multi-decadal to millennial timescales.

Sign in / Sign up

Export Citation Format

Share Document