@InProceedings{Cavalcanti:2010:MoSePr,
               author = "Cavalcanti, Iracema Fonseca de Albuquerque",
          affiliation = "{Instituto Nacional de Pesquisas Espaciais (INPE)}",
                title = "Monthly and seasonal precipitation anomalies variability over two 
                         sectors of la plata basin and extremes-observations and 
                         simulations from CPTEC/COLA AGCM",
            booktitle = "Abstracts...",
                 year = "2010",
         organization = "The Meeting of the Americas.",
            publisher = "AGU",
             keywords = "extreme events, precipitation, climate change, variability, global 
                         climate models.",
             abstract = "Center for Weather Forecast and Climate Studies, National 
                         Institute for Space Reseach, Cachoeira Paulista, Brazil AB: 
                         Persistent weather conditions associated with synoptic systems and 
                         large scale features, which cause extreme precipitation events can 
                         reflect on monthly and seasonal values above or bellow 
                         climatological average. These cases cause intense damage in 
                         agriculture, cattle rising and urban areas. Periods of extreme dry 
                         conditions affect also the agriculture and disturb the water 
                         resources to hydroelectricity power. The La Plata Basin, in South 
                         America has large areas of agriculture in Brazil, Uruguay, 
                         Paraguay and Argentina and is also the location of Itaipu, the 
                         largest hydroelectricity power in South America. Therefore, 
                         monthly and seasonal precipitation wet and dry extremes in the 
                         region have a profound effect on the economy and society. The La 
                         Plata Basin extends from 15S to 37S and it is influenced by 
                         different precipitation regimes. The northern sector has a well 
                         defined annual cycle with maximum precipitation in summer and 
                         minimum in winter, while the southern sector has a uniform and 
                         less amount of precipitation during the year. The northern sector 
                         is affected mainly by the South Atlantic Convergence Zone and 
                         frontal systems, while the southern sector is influenced by 
                         frontal systems, cyclonic vortices and mesoscale convective 
                         systems. The objective of this study is to identify extreme 
                         precipitation in the two sectors of La Plata Basin and the 
                         associated atmospheric characteristics (seasonal, monthly and 
                         daily) in the period of 1979 to 2001. Observed precipitation is 
                         analyzed from GPCP data, atmospheric features from ERA40 
                         reanalysis and SST from NOAA extended reconstructed SST. 
                         CPTEC/COLA AGCM T62L28 results are obtained from a 50 years 
                         climate simulation, initiated in 1950, and the same period of 1979 
                         to 2001 is analyzed. Extreme precipitation months and seasons are 
                         selected based on Standardized Precipitation Index (SPI) to select 
                         extreme, severe and moderate precipitation cases. The extreme 
                         cases, both monthly and seasonal, display the opposite relation 
                         between northern and southern LPB sectors in both observations and 
                         model simulation. Large scale characteristics of anomalous SST, 
                         Sea Level Pressure and geopotential anomalies, as well the wind 
                         flow at low and high levels are analyzed for the monthly and 
                         seasonal extremes. Timeseries of daily precipitation anomalies for 
                         extreme monthly precipitation representing each season shows the 
                         extreme events and the associated synoptic and mesoscale systems. 
                         Acknowledgements: To CLARIS LPB and CNPq for research support.",
  conference-location = "Foz do Igua{\c{c}}u",
      conference-year = "8-12 Aug. 2010",
             language = "en",
        urlaccessdate = "20 maio 2024"
}