Climate Indexes and Intraseasonal Influences on Brazilian Natural Hydropower Energy

Brazil’s large territorial extension provides the country unique characteristics, as it is influenced by a variety of dynamical systems with different spatial and temporal scales resulting in several climatic regimes in its subregions. The largest energy source for all regions is hydropower and a sequence of years with low precipitation depleted the reservoirs of a few areas, one of them is the northeast region.In this study we explore the annual and interannual characteristics of ten key areas with large average flow and how different Atlantic and Pacific related indexes influence those areas. The Madden-Julian Oscilation (MJO) influence was analyzed for intraseazonal signals. Monthly and daily flow rates from 1931 to 2015 were correlated with climate indexes such as Southern Oscillation Index (SOI), Niño 3.4, Niño 1+2, Multivariate ENSO Index (MEI), Atlantic Multidecadal Oscillation (AMO), Tropical South and North Atlantic Index (TSA and TNA) and North Atlantic Oscillation Index (NAO). Preliminary results indicate that areas located in the north and northeast of Brazil have larger correlation with Atlantic indexes and areas in the south and southeast have larger correlation with ENSO related indexes.The MJO index can have an enhancing or suppressing effect specially over the spring and summer seasons were rainfall is most abundant over most areas. MJO phases and rain anomaly are compared to determine the phases that have most influence.