Estrutura termohalina e massas de água ao norte da Península Antártica revelada a partir de dados in situ coletados por elefantes-marinhos do sul (Mirounga leonina)

Santini, Marcelo Freitas; Muelbert, Mônica M. C.; Souza, Ronald Buss de; Wainer, Ilana E. K. C.; Hindell, Mark A.

doi:10.4136/ambi-agua.893

Resumos

A Península Antártica Oeste é uma das regiões do planeta que está se aquecendo rapidamente e apresenta alta diversidade animal principalmente ao longo de sua plataforma continental. Esta região também é de grande importância devido à mistura causada pela interação de águas do Mar de Weddell (MW), do Estreito de Bransfield (EB) e da Corrente Circumpolar Antártica (CCA) que transmitem características termohalinas e nutrientes de diferentes locais de formação e mais tarde se conectam com todos os oceanos do planeta. Entretanto, estudos sobre a variabilidade temporal das condições oceanográficas desta região que consequentemente determinam a formação de massas d'água, são escassos em função das dificuldades logísticas envolvidas em levantamentos oceanográficos e monitoramentos tradicionais durante os meses de inverno. Para esse trabalho, variações da estrutura termohalina e das massas d'água nas proximidades e abaixo do gelo marinho na região norte da Península Antártica (PA) e Mar da Escócia (ME) foram registradas entre os meses de fevereiro e novembro de 2008 por duas fêmeas de elefante-marinho do sul (EMS, Mirounga leonina) instrumentadas com Conductivity - Temperature - Depth/Satellite-Relay Data Logger (CTD - SRDL). 1330 perfis verticais de temperatura e salinidade foram coletados por estes indivíduos que foram instrumentados pelo Projeto MEOP-BR na Ilha Elefante, Shetlands do Sul. Esses perfis, juntamente com diagramas de estado espalhado permitiram a identificação de massas d'água e suas alterações na estrutura vertical oceânica. Dentre as massas d'água identificadas citamos: Água de Superfície Antártica (AASW), Água de Inverno (WW), Água Cálida Profunda (WDW), Água Cálida Profunda Modificada (MWDW), Água Circumpolar Profunda (CDW), Água Profunda Circumpolar Superior (UCDW), Água Profunda Circumpolar Inferior (LCDW) e Água de Plataforma de Gelo (ISW). Nossos resultados mostram que a estrutura vertical oceânica sofre alterações que tradicionalmente não podem ser monitoradas, principalmente durante o inverno austral, e que os EMS são importantes e modernas plataformas para coleta de dados oceanográficos, permitindo um aumento em nosso conhecimento dos processos oceanográficos na região antártica.

Estrutura termohalina; massas de água; península Antártica; elefante-marinho do sul; oceano austral

The Western Antarctic Peninsula is rapidly warming and exhibits high indices of biodiversity concentrated mostly along its continental shelf. This region has great importance due to the the mixing caused by the interaction of waters from Weddell Sea (MW), Bransfield Strait (EB) and the Antarctic Circumpolar Current (CCA) transmits thermohaline characteristics and nutrients of different sites and finally connects with all the world's oceans. However, studies focusing on the temporal variability of the region's oceanographic conditions that finally determine the water mass formation are sparse due to the logistical difficulties of conducting oceanographic surveys and traditional monitoring during the winter. For this study, variations of the thermohaline structure and water masses in the vicinity and below the sea ice in the North of the Antarctic Peninsula (AP) and Scotia Sea (SS) were recorded between February and November 2008 by two female southern elephant seals (SES, Mirounga leonina) tagged with Conductivity - Temperature - Depth/Satellite-Relay Data Logger (CTD - SRDL). One thousand three hundred and thirty vertical profiles of temperature and salinity were collected by seals which were tagged by the MEOP-BR Project team at the Elephant Island, South Shetlands. These profiles, together with spread state diagrams allowed the identification of water masses and their variances in the ocean's vertical structure. Among the set of identified water masses we cite: Antarctic Surface Water (AASW), Winter Water (WW), Warm Deep Water (WDW), Modified Warm Deep Water (MWDW), Circumpolar Deep Water (CDW), Upper Circumpolar Deep Water (UCDW), Lower Circumpolar Deep Water (LCDW) and Ice Shelf Water (ISW). Our results show that the oceanic vertical structure undergoes changes that cannot be traditionally monitored, particularly during the Austral winter and that SES are important and modern oceanographic data collection platforms allowing for the improvement of our knowledge of oceanographic processes in the Antarctic region.

Thermohaline structure; water masses; Antarctic peninsula; southern elephant seal; austral ocean

BIUW, M. BOEHME, L.; GUINET, C.; HINDELL, M.; COSTA, D.; CHARRASSIN, J-B. et al. Variations in behavior and condition of a Southern Ocean top predator in relation to in situ oceanographic conditions. Proceedings of the National Academy of Sciences of the United States of America, v. 104, p. 13705-13710, 2007. http://dx.doi.org/10.1073/pnas.0701121104
BOEHME, L.; THORPE, S. E.; BIUW, M.; FEDAK, M.; MEREDITH, M. P. Monitoring Drake Passage with elephant seals: frontal structures and snapshots of transport. Limnology and Oceanography, v. 53, p. 2350-2360, 2008.
BOEHME, L.; LOVELL, P.; BIUW, M.; ROQUET, F.; NICHOLSON, J.; THORPE, S. E. et al. Technical Note: Animal-borne CTD-Satellite Relay Data Loggers for real-time oceanographic data collection. Ocean Science Discussions, v. 6, p. 1261-1287, 2009. http://dx.doi.org/10.5194/os-5-685-2009
CARTER, L.; MCCAVE, I. N.; WILLIAMS, J. M. Circulation and water masses of the southern ocean: a review. Developments in Earth and Environmental Sciences, v. 8, p. 85-114, 2008.
CHARRASSIN, J. B.; HINDELL, M.; RINTOUL, S. R.; ROQUET, F.; SOKOLOV, S.; BIUW, M. et al. Southern ocean frontal structure and sea-ice formation rates revealed by elephant seals. Proceedings of the National Academy of Sciences of the United States of America, v. 105, p. 11634 - 11639, 2008. http://dx.doi.org/10.1073/pnas.0800790105
DUARTE, V. S. Estrutura e variabilidade interanual das massas de água no Estreito de Bransfield (Antártica) durante os verões austrais de 2003 e 2004 2006. 143f. Dissertação (Mestrado em Geociências) - Programa de Pós-Graduação em Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre,2006.
FRANCO, B. C.; MATA, M. M.; PIOLA, A.; GARCIA, C. A. E. Northwestern Weddell Sea deep outflow into the Scotia Sea during the austral summers of 2000 and 2001 estimated by inverse methods. Deep Sea Research Part I, v. 54, p. 1815-1840, 2007. http://dx.doi.org/10.1016/j.dsr.2007.06.003
GORDON, A. L. Potential temperature, oxygen and circulation of bottom water in the Southern Ocean. Deep Sea Research and Oceanographic Abstracts, v. 13, p. 1125-1138, 1966. http://dx.doi.org/10.1016/0011-7471(66)90704-2
GORDON, A. L. Structure of Antarctic waters between 20ºW and 170ºW. New York: American Geographical Society, 1967. 10 p. (Antarctic Map Folio Series, Folio 6)
GORDON, A. L.; GEORGI, D. T.; TAYLOR, H. W. Antarctic polar front zone in the Western Scotia Sea-summer 1975. Journal of Physical Oceanography, v. 7, p. 309-328, 1977. http://dx.doi.org/10.1175/1520-0485(1977)007%3C0309:APFZIT%3E2. 0.CO;2
GORDON, A. L.; HUBER, B. A. Thermohaline stratification below the Southern Ocean sea ice. Journal of Geophysical Research, v. 89,n. C1, p. 641-648, 1984. http://dx.doi.org/10.1029/JC089iC01p00641
HEYWOOD, K. J.; NAVEIRA GARABATO, A. C.; STEVENS, D. P. High mixing rates in the abyssal Southern Ocean. Nature, v. 415, p. 1011 - 1014, 2002.
HEYWOOD, K. J.; NAVEIRA GARABATO, A. C.; STEVENS, D. P.; MUENCH, R. D. On the fate of the Antarctic Slope Front and the origin of the Weddell Front. Journal of Geophysical Research, v. 109, p. 1-13, 2004. http://dx.doi.org/10.1029/2003JC002053
HOFMANN, E. E.; KLINCK, J. M. Thermohaline variability of the waters overlying the west Antarctic continental shelf. In: JACOBS, S. S.; WEISS, R. F. (Eds.). Ocean, ice, and atmosphere: interactions at the Antarctic continental margin, Washington, DC.: American Geophysical Union, 1998. V. 75. p. 67 - 81.
KLINCK, J. M.; HOFMANN, E. E.; BEARDSLEY, R. C.; SALIHOGLU, B.; HOWARD, S. Water-mass properties and circulation on the west Antarctic peninsula continental shelf in austral fall and winter 2001. Deep Sea Research Part II: Topical Studies in Oceanography, v. 51, p. 1925-1946, 2004. http://dx.doi.org/10.1016/j.dsr2.2004.08.001
LYDERSEN, C.; NOST, O. A.; LOVELL, P.; MCCONNELL, B. J.; GAMMELSROD, T.; HUNTER, C. et al Salinity and temperature structure of a freezing Arctic fjord-Monitored by white whales (Delphinapterus leucas). Geophysical Research Letter, v. 29, 2119, 2002. http://dx.doi.org/10.1029/2002GL015462
MANTYLA, A. W.; REID, J. L. Abyssal characteristics of the world ocean waters. Deep Sea Research, v. 30, p. 805-833, 1983. http://dx.doi.org/10.1016/0198-0149(83)90002-X
MCCONNELL, B. J.; CHAMBERS, C.; FEDAK, M. A. Foraging ecology of southern elephant seals in relation to the bathymetry and productivity of the Southern Ocean. Antarctic Science v. 4, p. 393-398, 1992.
MEREDITH, M. P.; NICHOLLS, K. W.; RENFREW, I. A.; BOEHME, L.; BIUW, M.; FEDAK, M. Seasonal evolution of the upper-ocean adjacent to the South Orkney Islands, Southern Ocean: Results from a "lazy biological mooring". Deep Sea Research Part II: Topical Studies in Oceanography, v. 58, p. 1569-1579, 2011. http://dx.doi.org/10.1016/j.dsr2.2009.07.008
MUENCH, R.; GUN, J. T. The Weddell-Scotia Confluence in Midwinter. Journal of Geophysical Research, v. 95, p. 18177-18190, 1990.
MUENCH, R. D.; HUBER, B. A.; GUNN, J. T.; HUSBY, D. M. The Weddell-Scotia marginal ice zone: physical oceanographic conditions, geographical and seasonal variability. Journal of Marine Systems, v. 3, p. 169-182, 1992. http://dx.doi.org/10.1016/0924-7963(92)90037-9
ORSI, A. H.; WHITWORTH III, T.; NOWLIN Jr.; W. D. On the meridional extent and fronts of the Antarctic Circumpolar Current. Deep Sea Research Part I: Oceanographic Research Papers, v. 42, p. 641-673, 1995. http://dx.doi.org/10.1016/0967-0637(95)00021-W
PATTERSON, S. L.; SIEVERS, H. A. The Weddell-Scotia confluence. Journal of Physical Oceanography, v. 10, p. 1584-1610, 1980. http://dx.doi.org/10.1175/1520-0485(1980)010%3C1584:TWSC%3E2.0.CO;2
SANTINI, M. F.; SOUZA, R. B.; MUELBERT, M. M. C. Análise preliminar de dados oceanográficos medidos no Oceano Austral a partir de plataformas de coleta de dados instaladas em Elefantes-marinhos do sul. In: SEMINÁRIO DE SOBRE PESQUISA ANTÁRTICA, 16., 2008, São Paulo. Anais... São José dos Campos: INPE, 2008.
THORPE, S. E.; HEYWOOD, K. J.; BRANDON, M. A.; STEVENS, D. P. Variability of the southern Antarctic Circumpolar Current front north of South Georgia. Journal of Marine Systems, v. 37, p. 87-105, 2002. http://dx.doi.org/10.1016/S0924-7963(02)00197-5
WHITWORTH III, T.; NOWLIN JR, W.; ORSI, A.; LOCARNINI, R.; SMITH, S. Weddell Sea shelf water in the Bransfield Strait and Weddell-Scotia Confluence. Deep Sea Research Part I: Oceanographic Research Papers, v. 41, p. 629-641, 1994. http://dx.doi.org/10.1016/0967-0637(94)90046-9
UNESCO. Algorithms for computation of fundamental properties of seawater. [S.l.]: 1983. p. 1-55. (UNESCO technical papers in marine science, 44)

Datas de Publicação

Publicação nesta coleção
08 Out 2013
Data do Fascículo
Abr 2013

This work is licensed under a Creative Commons Attribution 4.0 International License.

[1] BIUW, M. BOEHME, L.; GUINET, C.; HINDELL, M.; COSTA, D.; CHARRASSIN, J-B. et al. Variations in behavior and condition of a Southern Ocean top predator in relation to in situ oceanographic conditions. Proceedings of the National Academy of Sciences of the United States of America, v. 104, p. 13705-13710, 2007. http://dx.doi.org/10.1073/pnas.0701121104

[2] BOEHME, L.; THORPE, S. E.; BIUW, M.; FEDAK, M.; MEREDITH, M. P. Monitoring Drake Passage with elephant seals: frontal structures and snapshots of transport. Limnology and Oceanography, v. 53, p. 2350-2360, 2008.

[3] BOEHME, L.; LOVELL, P.; BIUW, M.; ROQUET, F.; NICHOLSON, J.; THORPE, S. E. et al. Technical Note: Animal-borne CTD-Satellite Relay Data Loggers for real-time oceanographic data collection. Ocean Science Discussions, v. 6, p. 1261-1287, 2009. http://dx.doi.org/10.5194/os-5-685-2009

[4] CARTER, L.; MCCAVE, I. N.; WILLIAMS, J. M. Circulation and water masses of the southern ocean: a review. Developments in Earth and Environmental Sciences, v. 8, p. 85-114, 2008.

[5] CHARRASSIN, J. B.; HINDELL, M.; RINTOUL, S. R.; ROQUET, F.; SOKOLOV, S.; BIUW, M. et al. Southern ocean frontal structure and sea-ice formation rates revealed by elephant seals. Proceedings of the National Academy of Sciences of the United States of America, v. 105, p. 11634 - 11639, 2008. http://dx.doi.org/10.1073/pnas.0800790105

[6] DUARTE, V. S. Estrutura e variabilidade interanual das massas de água no Estreito de Bransfield (Antártica) durante os verões austrais de 2003 e 2004 2006. 143f. Dissertação (Mestrado em Geociências) - Programa de Pós-Graduação em Geociências, Universidade Federal do Rio Grande do Sul, Porto Alegre,2006.

[7] FRANCO, B. C.; MATA, M. M.; PIOLA, A.; GARCIA, C. A. E. Northwestern Weddell Sea deep outflow into the Scotia Sea during the austral summers of 2000 and 2001 estimated by inverse methods. Deep Sea Research Part I, v. 54, p. 1815-1840, 2007. http://dx.doi.org/10.1016/j.dsr.2007.06.003

[8] GORDON, A. L. Potential temperature, oxygen and circulation of bottom water in the Southern Ocean. Deep Sea Research and Oceanographic Abstracts, v. 13, p. 1125-1138, 1966. http://dx.doi.org/10.1016/0011-7471(66)90704-2

[9] GORDON, A. L. Structure of Antarctic waters between 20ºW and 170ºW. New York: American Geographical Society, 1967. 10 p. (Antarctic Map Folio Series, Folio 6)

[10] GORDON, A. L.; GEORGI, D. T.; TAYLOR, H. W. Antarctic polar front zone in the Western Scotia Sea-summer 1975. Journal of Physical Oceanography, v. 7, p. 309-328, 1977. http://dx.doi.org/10.1175/1520-0485(1977)007%3C0309:APFZIT%3E2. 0.CO;2

[11] GORDON, A. L.; HUBER, B. A. Thermohaline stratification below the Southern Ocean sea ice. Journal of Geophysical Research, v. 89,n. C1, p. 641-648, 1984. http://dx.doi.org/10.1029/JC089iC01p00641

[12] HEYWOOD, K. J.; NAVEIRA GARABATO, A. C.; STEVENS, D. P. High mixing rates in the abyssal Southern Ocean. Nature, v. 415, p. 1011 - 1014, 2002.

[13] HEYWOOD, K. J.; NAVEIRA GARABATO, A. C.; STEVENS, D. P.; MUENCH, R. D. On the fate of the Antarctic Slope Front and the origin of the Weddell Front. Journal of Geophysical Research, v. 109, p. 1-13, 2004. http://dx.doi.org/10.1029/2003JC002053

[14] HOFMANN, E. E.; KLINCK, J. M. Thermohaline variability of the waters overlying the west Antarctic continental shelf. In: JACOBS, S. S.; WEISS, R. F. (Eds.). Ocean, ice, and atmosphere: interactions at the Antarctic continental margin, Washington, DC.: American Geophysical Union, 1998. V. 75. p. 67 - 81.

[15] KLINCK, J. M.; HOFMANN, E. E.; BEARDSLEY, R. C.; SALIHOGLU, B.; HOWARD, S. Water-mass properties and circulation on the west Antarctic peninsula continental shelf in austral fall and winter 2001. Deep Sea Research Part II: Topical Studies in Oceanography, v. 51, p. 1925-1946, 2004. http://dx.doi.org/10.1016/j.dsr2.2004.08.001

[16] LYDERSEN, C.; NOST, O. A.; LOVELL, P.; MCCONNELL, B. J.; GAMMELSROD, T.; HUNTER, C. et al Salinity and temperature structure of a freezing Arctic fjord-Monitored by white whales (Delphinapterus leucas). Geophysical Research Letter, v. 29, 2119, 2002. http://dx.doi.org/10.1029/2002GL015462

[17] MANTYLA, A. W.; REID, J. L. Abyssal characteristics of the world ocean waters. Deep Sea Research, v. 30, p. 805-833, 1983. http://dx.doi.org/10.1016/0198-0149(83)90002-X

[18] MCCONNELL, B. J.; CHAMBERS, C.; FEDAK, M. A. Foraging ecology of southern elephant seals in relation to the bathymetry and productivity of the Southern Ocean. Antarctic Science v. 4, p. 393-398, 1992.

[19] MEREDITH, M. P.; NICHOLLS, K. W.; RENFREW, I. A.; BOEHME, L.; BIUW, M.; FEDAK, M. Seasonal evolution of the upper-ocean adjacent to the South Orkney Islands, Southern Ocean: Results from a "lazy biological mooring". Deep Sea Research Part II: Topical Studies in Oceanography, v. 58, p. 1569-1579, 2011. http://dx.doi.org/10.1016/j.dsr2.2009.07.008

[20] MUENCH, R.; GUN, J. T. The Weddell-Scotia Confluence in Midwinter. Journal of Geophysical Research, v. 95, p. 18177-18190, 1990.

[21] MUENCH, R. D.; HUBER, B. A.; GUNN, J. T.; HUSBY, D. M. The Weddell-Scotia marginal ice zone: physical oceanographic conditions, geographical and seasonal variability. Journal of Marine Systems, v. 3, p. 169-182, 1992. http://dx.doi.org/10.1016/0924-7963(92)90037-9

[22] ORSI, A. H.; WHITWORTH III, T.; NOWLIN Jr.; W. D. On the meridional extent and fronts of the Antarctic Circumpolar Current. Deep Sea Research Part I: Oceanographic Research Papers, v. 42, p. 641-673, 1995. http://dx.doi.org/10.1016/0967-0637(95)00021-W

[23] PATTERSON, S. L.; SIEVERS, H. A. The Weddell-Scotia confluence. Journal of Physical Oceanography, v. 10, p. 1584-1610, 1980. http://dx.doi.org/10.1175/1520-0485(1980)010%3C1584:TWSC%3E2.0.CO;2

[24] SANTINI, M. F.; SOUZA, R. B.; MUELBERT, M. M. C. Análise preliminar de dados oceanográficos medidos no Oceano Austral a partir de plataformas de coleta de dados instaladas em Elefantes-marinhos do sul. In: SEMINÁRIO DE SOBRE PESQUISA ANTÁRTICA, 16., 2008, São Paulo. Anais... São José dos Campos: INPE, 2008.

[25] THORPE, S. E.; HEYWOOD, K. J.; BRANDON, M. A.; STEVENS, D. P. Variability of the southern Antarctic Circumpolar Current front north of South Georgia. Journal of Marine Systems, v. 37, p. 87-105, 2002. http://dx.doi.org/10.1016/S0924-7963(02)00197-5

[26] WHITWORTH III, T.; NOWLIN JR, W.; ORSI, A.; LOCARNINI, R.; SMITH, S. Weddell Sea shelf water in the Bransfield Strait and Weddell-Scotia Confluence. Deep Sea Research Part I: Oceanographic Research Papers, v. 41, p. 629-641, 1994. http://dx.doi.org/10.1016/0967-0637(94)90046-9

[27] UNESCO. Algorithms for computation of fundamental properties of seawater. [S.l.]: 1983. p. 1-55. (UNESCO technical papers in marine science, 44)

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Brasil

Estrutura termohalina e massas de água ao norte da Península Antártica revelada a partir de dados in situ coletados por elefantes-marinhos do sul (Mirounga leonina)

Thermohaline structure and water masses in the north of Antarctic Peninsula from data collected in situ by southern elephant seals (Mirounga leonina)

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