@InProceedings{CastroBona:2010:ImRoSe,
               author = "Castro, Christopher Alexander Cunningham and Bonatti, Paulo",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)} and {Instituto 
                         Nacional de Pesquisas Espaciais (INPE)}",
                title = "Impacts of the ross sea anomalous sea ice conditions on the 
                         Southern Hemisphere atmosphere",
            booktitle = "Posters",
                 year = "2010",
         organization = "The Meeting of the Americas.",
            publisher = "AGU",
             keywords = "sea ice, global climate models, ocean, atmosphere interactions.",
             abstract = "This work examines the impact, on the Southern Hemisphere 
                         atmosphere, of anomalous sea ice extension in the Ross Sea, from 
                         the standpoint of two opposite conditions: with reduced and 
                         increased sea ice cover. To achieve this goal we have designed an 
                         experiment with the Atmospheric General Circulation Model of the 
                         Center for Weather Forecast and Climate Studies (AGCM-CPTEC/INPE). 
                         The whole experiment was composed of three large ensembles, sized 
                         with 60 members each, in order to achieve a significant 
                         recognition of signal. One of them, the control experiment, was 
                         forced with climatological sea surface temperatures and sea ice 
                         cover. In the other two ensembles the sea ice cover distribution 
                         in the Ross Sea was synthesized, from actual observed anomalies, 
                         using the least and the most observed sea ice cover in the 
                         1979-2005 time series of measurements. Those experiments were 
                         named RO- and RO+, respectively. As expected, the sea ice cover 
                         primarily affects the heat fluxes from the ocean. When the sea ice 
                         layer is reduced (increased), the fluxes increase (reduce), and 
                         this effect is more evident in sensible than latent heat fluxes. 
                         The permanence for several weeks of those abnormal conditions is 
                         able to alter locally the pattern of low-level temperature. The 
                         results show positive (negative) temperature anomalies driven by 
                         the abnormal positive (negative) fluxes of heat due to the imposed 
                         sea ice perturbation. Thought the vertical penetration of the 
                         temperature anomalies is shallow, not exceeding the 700 hPa level, 
                         the sea ice cover anomaly imprints a discernible and permanent 
                         anomaly in the near-surface temperature field, as can be seen 
                         evaluating every member in the perturbed ensembles. A Principal 
                         Component Analysis of the hemispherical patterns of low-level 
                         temperature (925 hPa) identifies the local impact due to the sea 
                         ice cover in the first and second eigenvectors, for the RO- and 
                         RO+ respectively. The flux-driven anomalous patterns appeared 
                         merged with hemispherical patterns due to the internal variability 
                         of the model (CTRL). The difference between the CTRL and perturbed 
                         pattern depicts that part of the anomalous pattern not due to the 
                         internal variability. Among the most important results are the 
                         indications of a relationship between the state of sea ice cover 
                         in the Ross Sea and the low-level temperatures in subtropical and 
                         extratropical South America. The present results indicate that the 
                         relationship is such that the anomalies of temperature in South 
                         America are of reverse sign regarding the polarity of the sea ice 
                         anomaly in the Ross Sea.",
  conference-location = "Foz do Igua{\c{c}}u",
      conference-year = "8-12 Aug. 2010",
             language = "en",
           targetfile = "Christopher_IMPACTS.pdf",
        urlaccessdate = "29 jun. 2024"
}