Contrasting end-summer distribution of organic carbon along the Gerlache Strait, Northern Antarctic Peninsula: Bio-physical interactions
Autor: | Rodrigo Kerr, Cassia O. Farias, Cláudia Hamacher, Leticia Cotrim da Cunha, Mauricio M. Mata, Carlos Rafael Borges Mendes |
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Rok vydání: | 2018 |
Předmět: |
0106 biological sciences
Total organic carbon geography geography.geographical_feature_category 010504 meteorology & atmospheric sciences Mixed layer 010604 marine biology & hydrobiology chemistry.chemical_element Oceanography 01 natural sciences chemistry.chemical_compound Water column Nitrate chemistry Peninsula Environmental science Thermal front Hydrography Carbon 0105 earth and related environmental sciences |
Zdroj: | Deep Sea Research Part II: Topical Studies in Oceanography. 149:206-217 |
ISSN: | 0967-0645 |
Popis: | Dissolvedorganic carbon (DOC) was determined at the Gerlache Strait, a coastal area off the Northern Antarctic Peninsula, in the austral summers of 2015 and 2016 during NAUTILUS I and II cruises, respectively. Hydrographic conditions in the area were very different between the study years. Despite that, the surface mixed layer displayed higher DOC concentrations compared to intermediate and deeper waters, as a result of the strong water column stratification, for both years. DOC accumulation on the surface is significantly related to the net community production (NCP), and stronger when the nitrate surface deficit (ΔNO3-) is higher (2016). The presence of a surface/subsurface thermal front at the central Gerlache Strait likely promotes the export of surface-produced organic carbon to deeper layers. A weak correlation between DOC and apparent oxygen utilization (AOU) suggests that the degradationof organic carbon in the deeper water column has a small role in oxygen consumption (less than 10%). This “recalcitrant” DOC characteristic below the surface layers observed in this study is similar to that found twenty years ago in the same area (FRUELA campaign, early Summer 1995). The Gerlache Strait allows, as an adequate regional scale study, assessments on the efficiency of the export and distribution of organic carbon in deep water masses in view of the observed trends of freshening, cooling, and lightening in the Antarctic Peninsula shelf waters. |
Databáze: | OpenAIRE |
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