@Article{NobreMourSun:2001:DyDoSe,
               author = "Nobre, Paulo and Moura, Antonio Divino and Sun, Liqiang",
          affiliation = "{Centro de Previsao de Tempo e Estudos Climaticos - CPTEC/INPE} 
                         and Lamont-Doherty Earth Observatory of Columbia University, 
                         Palisades, New York",
                title = "Dynamical downscaling of seasonal climate prediction over Nordeste 
                         Brazil with NCEP's regional spectral model at IRI",
              journal = "Bulletin of the American Meteorological Society",
                 year = "2001",
               volume = "82",
               number = "12",
                pages = "2787--2796",
                month = "dec.",
             keywords = "sea-surface temperature, precipitation, rainfall, system.",
             abstract = "This study presents an evaluation of a seasonal climate forecast 
                         done with the International Research Institute for Climate 
                         Prediction (IRI) dynamical forecast system (regional model nested 
                         into a general circulation model) over northern South America for 
                         January–April 1999, encompassing the rainy season over Brazil’s 
                         Nordeste. The one-way nesting is one in two tiers: first the 
                         NCEP’s Regional Spectral Model (RSM) runs with an 80-km grid mesh 
                         forced by the ECHAM3 atmospheric general circulation model (AGCM) 
                         outputs; then the RSM runs with a finer grid mesh (20 km) forced 
                         by the forecasts generated by the RSM-80. An ensemble of three 
                         realizations is done. Lower boundary conditions over the oceans 
                         for both ECHAM and RSM model runs are sea surface temperature 
                         forecasts over the tropical oceans. Soil moisture is initialized 
                         by ECHAM’s inputs. The rainfall forecasts generated by the 
                         regional model are compared with those of the AGCM and 
                         observations. It is shown that the regional model at 80-km 
                         resolution improves upon the AGCM rainfall forecast, reducing both 
                         seasonal bias and root-mean-square error. On the other hand, the 
                         RSM-20 forecasts presented larger errors, with spa-tial patterns 
                         that resemble those of local topography. The better forecast of 
                         the position and width of the intertropical convergence zone 
                         (ITCZ) over the tropical Atlantic by the RSM-80 model is one of 
                         the principal reasons for better-forecast scores of the RSM-80 
                         relative to the AGCM. The regional model improved the spatial as 
                         well as the tempo-ral details of rainfall distribution, and also 
                         presenting the minimum spread among the ensemble members. The 
                         statistics of synoptic-scale weather variability on seasonal 
                         timescales were best forecast with the regional 80-km model over 
                         the Nordeste. The possibility of forecasting the frequency 
                         distribution of dry and wet spells within the rainy season is 
                         encouraging.",
           copyholder = "SID/SCD",
                 issn = "0003-0007",
             language = "en",
           targetfile = "Nobre_Dynamical downscaling.pdf",
        urlaccessdate = "15 maio 2024"
}