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Takao, Shintaro; Nakaoka, Shin-ichiro; Hashihama, Fuminori; Shimada, Keishi; Yoshikawa-inoue, Hisayuki; Hirawake, Toru; Kanda, Jota; Hashida, Gen; Suzuki, Koji. |
The Southern Ocean is a vast net sink for atmospheric carbon dioxide (CO2), with marine phytoplankton playing a crucial role in CO2 fixation. We assessed how changes in the dominant phytoplankton community and net primary productivity (NPP) affected variations in the partial pressure of CO2 in surface water (pCO(2)(sw)) in the Indian sector of the Southern Ocean during austral summer. pCO2sw was negatively correlated with total phytoplankton and diatom abundances, as estimated from pigment signatures, in the zone south of the Antarctic Circumpolar Current; however, pCO(2)(sw) was not correlated with haptophyte abundance. Additionally, a stronger correlation was found between pCO(2)(sw) and total phytoplankton NPP than between chlorophyll a concentration... |
Tipo: Text |
Palavras-chave: Phytoplankton community composition; Diatoms; Southern Ocean; Net primary productivity; Carbon dioxide. |
Ano: 2020 |
URL: https://archimer.ifremer.fr/doc/00676/78836/81084.pdf |
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Preunkert, Susanne; Legrand, Michel; Jourdain, Bruno; Moulin, Cyril; Belviso, Sauveur; Kasamatsu, Nobue; Fukuchi, Mitsuo; Hirawake, Toru. |
A multiple year-round study of atmospheric dimethyl sulfide (DMS) (from December 1998 to April 2003) as well as sulfur-derived aerosols (methanesulfonic acid (MSA) and non-sea-salt sulfate) (from March 1991 to February 2003) was conducted at Dumont d'Urville, coastal Antarctica. The three sulfur-derived species exhibit a seasonal cycle characterized by maxima in midsummer (January). Whereas the interannual variability of winter levels remains low, a strong interannual variability is shown in summer, particularly for DMS and MSA, and to a lesser extent for non-sea-salt sulfate. Over the 1998-2003 time period, January 2002 stands out with high values for all sulfur species. These interannual variabilities of atmospheric summer levels are examined in the... |
Tipo: Text |
Palavras-chave: Sulfur cycle; Antarctica; Dimethylsulfure. |
Ano: 2007 |
URL: https://archimer.ifremer.fr/doc/00236/34728/33177.pdf |
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Koubbi, Philippe; Ozouf-costaz, Catherine; Goarant, Anne; Moteki, Masato; Hulley, Percy-alexander; Causse, Romain; Dettai, Agnes; Duhamel, Guy; Pruvost, Patrice; Tavernier, Eric; Post, Alexandra L.; Beaman, Robin J.; Rintoul, Stephen R.; Hirawake, Toru; Hirano, Daisuke; Ishimaru, Takashi; Riddle, Martin; Hosie, Graham. |
Ecoregions are defined in terms of community structure as a function of abiotic or even anthropogenic forcing. They are meso-scale structures defined as the potential habitat of a species or the predicted communities geographic extent. We assume that they can be more easily defined for long-lived species, such as benthos or neritic fish, in the marine environment. Uncertainties exist for the pelagic realm because of its higher variability, plus little is known about the meso- and bathypelagic zones. A changing environment and modification of habitats will probably drive new communities from plankton to fish or top predators. We need baseline studies, such as those of the Census of Antarctic Marine Life, and databases like SCAR-MarBIN as tools for... |
Tipo: Text |
Palavras-chave: East Antarctic shelf; Ichthyofauna; Ecoregionalisation; Generalized dissimilarity modeling; Dumont d'Urville Sea. |
Ano: 2010 |
URL: https://archimer.ifremer.fr/doc/00236/34740/33086.pdf |
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