@InProceedings{DrumondAmbr:2006:RoSoIn,
               author = "Drumond, Anita Rodrigues de Moraes and Ambrizzi, Tercio",
          affiliation = "Instituto de Astronomia, Geofisica e Ciencias Atmosfericas, 
                         Universidade de Sao Paulo (IAG/USP) and Rua do Matao, 1226, 
                         05508-090, Sao Paulo, SP, Brazil (Drumond,Ambrizzi)",
                title = "The role of the South Indian and South Pacific oceans on the South 
                         American monsoon variability",
            booktitle = "Proceedings...",
                 year = "2006",
               editor = "Vera, Carolina and Nobre, Carlos",
                pages = "1021--1023",
         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 = "South American monsoon system, South Indian, South Pacific, REOF, 
                         GCM.",
             abstract = "This work investigates the impact of three different low-frequency 
                         Sea Surface Temperature (SST) variability modes located in the 
                         Indian and the Pacific oceans over the interannual variability of 
                         the South American Monsoon System (SAMS) using observed and 
                         numerical simulation analysis. The low-frequency variability of 
                         the SAMS is characterized by a meridional seesaw of dry and wet 
                         conditions over tropical and subtropical South America associated 
                         to the modulation of the South Atlantic Convergence Zone (SACZ). 
                         Rotated Empirical Orthogonal Function (REOF) analysis was applied 
                         over the normalized Summer (December, January and February) 
                         Reynolds SST anomalies observed during the period 1950-2001 in the 
                         South Pacific+Equatorial Pacific (SEP) and in the Indian (IN) 
                         oceans. For each region, the modes obtained via EOF were rotated 
                         using Varimax and the rotated modes were examined through 
                         composites of extremes events selected by applying a threshold of 
                         one standard deviation over their normalized Principal Component 
                         time series (CP). For the numerical simulations the Community 
                         Climate Model version 3.6 (CCM3.6) General Circulation Model (MCG) 
                         was used. The model was forced with the positive phase of the 
                         selected SST modes, considered as SST anomalies, through an 
                         ensemble technique with five integrations. The simulations were 
                         run from September/year 0 to March/year 1 and the SST anomalies 
                         are kept fixed during the integration, while the monthly SST 
                         climatology varies outside. For the IN, the second mode explains 
                         12% of the total variance and it is localized around 25šS;80šE. 
                         According to the composites, warmer waters over this region are 
                         associated with enhanced austral summer precipitation over 
                         subtropics. The GCM is able to reproduce this anomalous 
                         precipitation pattern, simulating a wave train emanating from the 
                         IN towards the SA. The second SEP mode (explaining 12,4% of the 
                         total variance) consists of a region extending from the 
                         subtropical southwestern Pacific towards the Indonesia, where the 
                         maximum loading is located. REOF analysis indicates that warmer 
                         waters over this region are associated with drought conditions 
                         over the SACZ and enhanced precipitation over the subtropics. 
                         There is a wave train emanating from Indonesia towards the SA via 
                         the tropics and another weaker one via the subtropics. The MCG 
                         indicates that the warmer waters over the Indonesia generate 
                         drought conditions over the tropical SA through a PSA-like wave 
                         pattern emanating from the western Pacific. Finally, the sixth SEP 
                         mode explains 6% of the total variance and it consists in a region 
                         located over the Southwestern Pacific reaching the maximum value 
                         near to the New Zealand. The composites indicate that warmer 
                         waters over this region are associated with enhanced precipitation 
                         over the SACZ and drought conditions over the subtropics. There is 
                         a PSA-like wave train emanating from the Indonesia towards SA and 
                         another one crossing the Southern Hemisphere in the extratropics 
                         probably associated with the transients activity. The GCM is able 
                         to reproduce the anomalous precipitation pattern, although weaker. 
                         The PSA-like pattern is simulated, but the model fails in 
                         reproducing the extratropical wave activity.",
  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/2005/10.13.18.20",
                  url = "http://urlib.net/ibi/cptec.inpe.br/adm_conf/2005/10.13.18.20",
           targetfile = "1021-1024.pdf",
                 type = "Monsoon systems and continental rainfall",
        urlaccessdate = "05 maio 2024"
}