Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2016-05-31T20:42:21Z No. of bitstreams: 1 MayteDuarteLealCoutinho_TESE.pdf: 5311317 bytes, checksum: abfa1929995ae7c350372d6daa5498e6 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2016-06-03T20:03:24Z (GMT) No. of bitstreams: 1 MayteDuarteLealCoutinho_TESE.pdf: 5311317 bytes, checksum: abfa1929995ae7c350372d6daa5498e6 (MD5) / Made available in DSpace on 2016-06-03T20:03:24Z (GMT). No. of bitstreams: 1 MayteDuarteLealCoutinho_TESE.pdf: 5311317 bytes, checksum: abfa1929995ae7c350372d6daa5498e6 (MD5) Previous issue date: 2015-06-18 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / No contexto de mudan?as clim?ticas sobre a Am?rica do Sul (AS) tem-se observado que a combina??o de altas temperaturas mais chuvas e altas temperaturas menos chuvas, provocam diferentes impactos como: eventos extremos de precipita??o, condi??es favor?veis para queimadas e secas. Com isto, estas regi?es enfrentam amea?a crescente de escassez de ?gua, local ou generalizada. Assim, a disponibilidade de ?gua no Brasil depende em grande parte, do clima e de suas varia??es em diversas escalas de tempo. Neste sentido, o objetivo principal desta pesquisa ? estudar o balan?o de umidade por meio de Regional Climate Models (RCM) do Project Regional Climate Change Assessments for La Plata Basin (CLARIS- LPB), assim como, combinar estes RCM por meio de duas t?cnicas estat?sticas, na tentativa de melhorar a previs?o sobre tr?s ?reas da AS: Amaz?nia (AMZ), Nordeste do Brasil (NEB) e Bacia do Prata (LPB) nos climas do passado (1961-1990) e do futuro (2071-2100). O transporte de umidade sobre AS foi investigado por meio do fluxo de umidade integrado verticalmente. Os principais resultados mostraram que os fluxos m?dios de vapor d??gua nas regi?es tropicais (AMZ e NEB) s?o maiores atrav?s das bordas leste e norte, assim indicando que as contribui??es dos ventos al?sios do Atl?ntico Norte e do Sul s?o igualmente importantes para a entrada de umidade durante os meses de JJA e DJF. Esta configura??o foi observada em todos os modelos e climas. Na compara??o dos climas verificou-se que a converg?ncia do fluxo de umidade no clima passado foi menor em rela??o ao futuro em diferentes regi?es e ?pocas. De forma semelhante, constatou-se que a precipita??o foi reduzida no clima futuro nas regi?es tropicais (AMZ e NEB), possivelmente devido os intensos fluxos de umidade que adentraram nas regi?es. Por interm?dio das t?cnicas de Regress?o M?ltipla por Componente Principal (C_RCP) e da combina??o convexa (C_EQM), analisamos e comparamos as combina??es dos modelos (ensemble). Os resultados indicaram que a combina??o por RCP foi melhor em representar a precipita??o observada em ambos os climas. Sendo que, al?m dos valores mostrarem ser pr?ximos aos observados, a t?cnica obteve coeficiente de correla??o de moderada ? forte magnitude, em praticamente todos os meses nos diferentes climas e regi?es. Al?m do mais, na avalia??o das t?cnicas de combina??o, a tend?ncia percentual (PBIAS) mostrou que em geral, a C_RCP obteve valores de baixa magnitude (PBIAS = 0%) indicando ter um desempenho ?muito bom? no clima passado e (PBIAS = -4% a 3%) para o clima futuro, sobre as regi?es de estudo. Enquanto a C_EQM mostrou no clima passado, que a AMZ obteve um desempenho ?bom? e nas regi?es do NEB e LPB obtiveram desempenho de ?bom a satisfat?rio?. Logo, os resultados mostraram que as t?cnicas tem um potencial promissor para aplica??es operacionais em centro de previs?o de tempo e clima. / In the context of climate change over South America (SA) has been observed that the combination of high temperatures and rain more temperatures less rainfall, cause different impacts such as extreme precipitation events, favorable conditions for fires and droughts. As a result, these regions face growing threat of water shortage, local or generalized. Thus, the water availability in Brazil depends largely on the weather and its variations in different time scales. In this sense, the main objective of this research is to study the moisture budget through regional climate models (RCM) from Project Regional Climate Change Assessments for La Plata Basin (CLARIS-LPB) and combine these RCM through two statistical techniques in an attempt to improve prediction on three areas of AS: Amazon (AMZ), Northeast Brazil (NEB) and the Plata Basin (LPB) in past climates (1961-1990) and future (2071-2100). The moisture transport on AS was investigated through the moisture fluxes vertically integrated. The main results showed that the average fluxes of water vapor in the tropics (AMZ and NEB) are higher across the eastern and northern edges, thus indicating that the contributions of the trade winds of the North Atlantic and South are equally important for the entry moisture during the months of JJA and DJF. This configuration was observed in all the models and climates. In comparison climates, it was found that the convergence of the flow of moisture in the past weather was smaller in the future in various regions and seasons. Similarly, the majority of the SPC simulates the future climate, reduced precipitation in tropical regions (AMZ and NEB), and an increase in the LPB region. The second phase of this research was to carry out combination of RCM in more accurately predict precipitation, through the multiple regression techniques for components Main (C.RPC) and convex combination (C.EQM), and then analyze and compare combinations of RCM (ensemble). The results indicated that the combination was better in RPC represent precipitation observed in both climates. Since, in addition to showing values be close to those observed, the technique obtained coefficient of correlation of moderate to strong magnitude in almost every month in different climates and regions, also lower dispersion of data (RMSE). A significant advantage of the combination of methods was the ability to capture extreme events (outliers) for the study regions. In general, it was observed that the wet C.EQM captures more extreme, while C.RPC can capture more extreme dry climates and in the three regions studied.