@InProceedings{SilveiraCostVascMene:2010:CaRCPr,
               author = "Silveira, Cleiton D and Costa, A A and Vasconcelos J{\'u}nior, F 
                         D and Menezes, Otac{\'{\i}}lio Leandro",
          affiliation = "DEMET, Funda{\c{c}}{\~a}o Cearense de Meteorologia e Recursos 
                         H{\'{\i}}dricos, Fortaleza-CE, Brazil and Mestrado em 
                         Ci{\^e}ncias F{\'{\i}}sicas Aplicadas, Universidade Estadual do 
                         Cear{\'a}, Fortaleza, Brazil and Mestrado em Ci{\^e}ncias 
                         F{\'{\i}}sicas Aplicadas, Universidade Estadual do Cear{\'a}, 
                         Fortaleza, Brazil and {Instituto Nacional de Pesquisas Espaciais 
                         (INPE)}",
                title = "Can RCMs Properly Represent the Diurnal Cycle of Precipitation in 
                         the Tropics? Evaluating the Northeast Brazil Case",
            booktitle = "Posters",
                 year = "2010",
         organization = "The Meeting of the Americas.",
            publisher = "AGU",
             keywords = "convective processes, atmospheric sciences.",
             abstract = "A number of physical processes act in modulating the occurrence of 
                         deep convection and precipitation over land and over ocean in 
                         tropical regions. Although it is quite obvious that the 
                         differential heating is responsible for establishing direct 
                         thermal circulations, large-scale advection and the internal 
                         evolution and dynamics of cloud systems (which depend on the 
                         microphysics) are also important to the diurnal distribution of 
                         precipitation in a given region. In this work, we analyze the 
                         capability of a regional climate model (Regional Atmospheric 
                         Modeling System, version 6.0, forced by ECHAM 4.5 AMIP runs) in 
                         simulating the diurnal cycle of precipitation over Northeast 
                         Brazil. The model results come from a 46-year, 15-member, 
                         climatological simulate,n performed as part of the upgrade of an 
                         operational dynamical downscaling forecast system at the 
                         Cear{\'a} State Foundation for Meteorology and Water Resources 
                         (FUNCEME). Model grid has 100 x 100 points in the horizontal, for 
                         a grid spacing of 30 km in both directions zonal and meridional, 
                         covering Northeast Brazil and a portion of the intertropical 
                         Atlantic ocean. In order to conduct the verification of model 
                         results, data from FUNCEME's network of surface stations were 
                         used. As the stations produce hourly precipitation data, one 
                         determined the time of maximum precipitation over the state of 
                         Cear{\'a}, in Northeast Brazil. As expected, most of the coastal 
                         stations exhibit maximum precipitation rates in local morning 
                         hours, whereas afternoon precipitation dominated inland. 
                         Mountaneous regions to the northwest and to the south of 
                         Cear{\'a} state have opposite behaviors, the first with the 
                         predominance of afternoon rainfall; the later, with precipitation 
                         occurring mostly during late night and early morning hours. In 
                         contrast with this complex behavior, modeled precipitation shows a 
                         mostly binary signal, with afternoon precipitation dominating over 
                         the entire continent and night to morning rainfall being 
                         restricted to the ocean areas within the model domain. Those 
                         discrepancies suggest that the RCM has serious limitations in 
                         representing the generation of instability and the interaction 
                         between convection and larger-scale advection, even with an 
                         adequate representation of the diurnal cycle of surface heating 
                         and cooling and the simulation of local wind patterns associated 
                         with the sea breeze and topography-forced circulations. With a 
                         resolution on the order of tens of kilometers, precipitation is 
                         mostly simulated via convective parameterizations. Hence, it is 
                         possible that the local removal of instability with rainfall being 
                         produced in a given model column does not correspond to the real 
                         evolving cloud system which are transported by the larger scale 
                         flow at the same time as they pass through growing, mature and 
                         dissipating stages.",
  conference-location = "Foz do Igua{\c{c}}u",
      conference-year = "08-12 Aug. 2010",
             language = "en",
           targetfile = "Silveira_can.pdf",
        urlaccessdate = "20 maio 2024"
}