Impacts of Global Ocean Warming on Climate over Brazil with the OLAM Model

The ocean is the main driver of the global climate variability. Phenomena like El Niņo, La Niņa and the Atlantic Dipole usually affect the climate in several regions including the South America and Brazil. Understanding the impact of these phenomena on the regional climate is of great importance. Several studies had evaluated the impact of oceanic global changes using climate models. However, those global models have low spatial resolution and therefore, they are not able to represent the regional climate changes properly. The new model OLAM (Ocean Land Atmosphere Model) can represent simultaneously the global and regional climate phenomena through use of a grid refinement system. In this study, the OLAM model was set up with a global grid having a horizontal grid space on the order of 200 km and a grid refinement for the Brazilian region and surroundings with a 32 km grid cell. The model was initially integrated for the period between 1960 and1990 to build a climatological run. After that, the Sea Surface Temperature (SST) data scenarios from the Hadley Center Model were used as a surface boundary condition to perform a new run for the XXI century. Comparison between the XXI century run and the climatological control run produced a decrease in precipitation mainly over the northeast Brazil and an increase over the west and south Brazil. In general, those scenarios produced with this higher spatial resolution approach produced similar results from the other GCMs, but in this case it allowed a better regional evaluation of the possible climate change for the regions of this study.