@Article{KayanoFerrRami:1997:SuCiPa,
               author = "Kayano, Mary T. and Ferreira, N. J. and Ramirez, M. C. V.",
          affiliation = "{CPTEC-INPE-Cachoeira Paulista-12630-000-SP-Brasil}",
                title = "Summer circulation patterns related to the upper tropospheric 
                         vortices over the tropical South Atlantic",
              journal = "Meteorology and Atmospheric Physics",
                 year = "1997",
               volume = "64",
               number = "3-4",
                pages = "203--213",
             keywords = "rainfall anomalies, oscillation, atmosphere, America.",
             abstract = "Daily 200-hPa relative vorticity data have been used to study the 
                         dominant patterns related to the cyclonic vortices over the South 
                         Atlantic Ocean in the vicinities of northeast Brazil, during the 
                         1980-1989 period. Reference modes were obtained through empirical 
                         orthogonal function (EOF) analysis of the 200-hPa filtered 
                         vorticity anomalies over northeast Brazil, considering all the 
                         southern hemisphere (SH) summers within the study period. The 
                         amplitude time series of the first reference mode, separately for 
                         each SH summer, was correlated with the corresponding filtered 
                         vorticity anomalies in a larger area extending from 20 degrees N 
                         to 40 degrees S and between 120 degrees W and 20 degrees W. The 
                         correlation patterns feature a wave-like structure along eastern 
                         South America, with three main centers: the first one, over the 
                         South Atlantic off the northeast Brazil coast, is associated with 
                         the cyclonic vortices; the second one, over eastern Brazil, 
                         represents the corresponding anomalously amplified ridges; and the 
                         third one, over southern Brazil/Uruguay, is related to the 
                         equatorward incursions of midlatitude upper level troughs. This 
                         wave-like pattern is consistent with the vortex formation 
                         mechanism suggested in previous works. Another wave-like pattern 
                         southwest-northeast oriented is evident over the tropical 
                         southeastern Pacific, for some years. The interannual variability 
                         of these patterns is discussed in this paper.",
           copyholder = "SID/SCD",
                 issn = "0177-7971",
             language = "en",
           targetfile = "1997_kayano.pdf",
        urlaccessdate = "02 maio 2024"
}