@InProceedings{ColbergReas:2006:OcMoDi,
               author = "Colberg, F. and Reason, C. J. C.",
          affiliation = "{Department of Oceanography} and {University of Cape Town} and 
                         {Private Bag X3} and Rondebosch, 7701 and {South Africa}",
                title = "Ocean Model Diagnosis of Low Frequency Climate Variability in the 
                         South Atlantic",
            booktitle = "Proceedings...",
                 year = "2006",
               editor = "Vera, Carolina and Nobre, Carlos",
                pages = "1509--1512",
         organization = "International Conference on Southern Hemisphere Meteorology and 
                         Oceanography, 8. (ICSHMO).",
            publisher = "American Meteorological Society (AMS)",
              address = "45 Beacon Hill Road, Boston, MA, USA",
             keywords = "coupled ocean atmosphere, modelling, low frequence variability.",
             abstract = "South Atlantic Ocean variability is investigated by means of an 
                         ocean general circulation model (ORCA2), forced with the NCEP/ 
                         NCAR-reanalysis for the 1948-1999 period.A rotated EOF analysis of 
                         the mixed layer temperature suggests a breakdown of the South 
                         Atlantic into three subdomains, with characteristic spatial and 
                         temporal scales: (a) the tropical Atlantic, with mainly 
                         interannual fluctuations, (b) the subtropics, with variability on 
                         an interannual to decadal scale, and (c) the midlatitudes, with 
                         interannual and multidecadal variability. These modes are closely 
                         connected to anomalous atmospheric circulation patterns, which 
                         induce typical forcing mechanisms for each region. Temperature 
                         changes in the western to central tropics are found to be driven 
                         by changes in surface heat fluxes and horizontal advection of 
                         heat, while in the central to eastern tropics and the northern 
                         Benguela, temperature changes are connected to reduced vertical 
                         entrainment, altering the depth of the mixed layer and leading to 
                         reduced upwelling. In the subtropics, changes in the net surface 
                         fluxes drive the upper ocean temperature anomalies, and wind 
                         induced vertical mixing dissipates them, inducing changes in the 
                         depth of the mixed layer. Anomalous heat and volume transports are 
                         found to be related to anomalous Ekman and geostrophic currents. A 
                         wind driven mechanism is suggested, whereby changes in Ekman 
                         related heat and volume transport lead to modulations of the 
                         subtropical gyre and thus to changes in the geostrophic related 
                         heat and volume transport. The midlatitudes experience temperature 
                         changes mainly due to horizontal advection and wind induced 
                         vertical mixing, whereby geostrophic advection of heat dominates 
                         in the western to central area, and Ekman induced heat transports 
                         are confined to the eastern midlatitudes. Results from a SVD 
                         analysis between mixed layer temperatures and sea level pressure 
                         suggests that these forcing mechanisms, their associated regions 
                         and time scales, as well as heat and volume transports are also 
                         valid for the coupled ocean-atmosphere system. end{abstract}.",
  conference-location = "Foz do Igua{\c{c}}u",
      conference-year = "24-28 Apr. 2006",
             language = "en",
         organisation = "American Meteorological Society (AMS)",
                  ibi = "cptec.inpe.br/adm_conf/2005/10.14.09.47",
                  url = "http://urlib.net/ibi/cptec.inpe.br/adm_conf/2005/10.14.09.47",
           targetfile = "1509-1512.pdf",
                 type = "Understanding long-term climate variations in the SH",
        urlaccessdate = "20 maio 2024"
}