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@Article{LessaSantVanaAlbu:2017:OfExBr,
               author = "Lessa, Douglas V. O. and Santos, Thiago P. and Vanancio, Igor 
                         Martins and Albuquerque, Ana Luiza S.",
          affiliation = "{Universidade Federal Fluminense (UFF)} and {Universidade Federal 
                         Fluminense (UFF)} and {Instituto Nacional de Pesquisas Espaciais 
                         (INPE)} and {Universidade Federal Fluminense (UFF)}",
                title = "Offshore expansion of the Brazilian coastal upwelling zones during 
                         Marine Isotope Stage 5",
              journal = "Global and Planetary Change",
                 year = "2017",
               volume = "158",
                pages = "13--20",
                month = "Nov.",
             keywords = "UpwellingPlanktonic foraminiferaBrazil 
                         CurrentEccentricityPaleoceanography.",
             abstract = "Paleoceanographic reconstructions in upwelling regions can provide 
                         relevant information about changes in primary productivity, 
                         oceanatmosphere interactions and the carbon budget. Here, we 
                         assessed new data on planktonic foraminifera from a sediment core 
                         located near to coastal upwelling zones along the Brazilian coast. 
                         Our new data was combined with previous records to reveal the 
                         state of upwelling systems along the western South Atlantic margin 
                         throughout the last two deglacial and interglacial periods sensu 
                         lato. Despite the contemporary oligotrophic scenario of the Santos 
                         Basin, a remarkably high relative abundance of Globigerina 
                         bulloides and low temperatures at a depth of 100 m indicated 
                         upwelling conditions similar to current shelf upwelling zones from 
                         130 to 90 kyr BP. Comparing these results with previous studies, 
                         we argue that Brazilian shelf upwelling zones expanded offshore 
                         between 20 and 28S. We develop two conceptual scenarios to 
                         characterize the system: (1) during Marine Isotopic Stage (MIS 5), 
                         the system expanded along the continental margin between 20 and 
                         28S following the eccentricity maximum; and (2) after 20 kyr BP, 
                         the system retracted to current continental shelf zones. We 
                         propose a new mechanism whereby variation of the Earth's 
                         eccentricity, which drives seasonality, is the main factor 
                         controlling expansion or retraction of the Brazilian upwelling 
                         system. Absence of such conditions in more recent periods supports 
                         our model and indicates that current upwelling zones are the 
                         remnants of a larger upwelling system. However, more studies are 
                         required to better define the latitudinal boundaries of the 
                         Brazilian upwelling system in the past and its possible influences 
                         over the regional carbon budget.",
                  doi = "10.1016/j.gloplacha.2017.09.006",
                  url = "http://dx.doi.org/10.1016/j.gloplacha.2017.09.006",
                 issn = "0921-8181",
             language = "en",
           targetfile = "lessa_offshore.pdf",
        urlaccessdate = "30 nov. 2020"
}


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