Efeitos do Dipolo do Atlântico Tropical sobre as forçantes da circulação oceânica

Abstract

This study aims to describe and quantify the effects of the Tropical Atlantic Dipole like pattern over the composites of ocean circulation (i.e. heat flux, water flux – evaporation and precipitation – and wind), giving closer attention to Fortaleza’s region. It used monthly reanalyses data from the model ERA-Interim for five variables: sea surface temperature, precipitation, evaporation, wind and total heat flux. Data period ranges from 1979 to 2013 – 35 years. It utilized the Dipole Index from Servain dataset. It calculated the monthly mean anomaly of each variable for each year and correlated them to the positive Dipole events (above +0,5 Dipole Index) and negative Dipole events (below -0,5 Dipole Index), during rainy season (March – April) and dry season (October – November). It considered Fortaleza’s grid for the correlation data. The author quantified the effect of Dipole events by relating the monthly mean anomaly to the climatological monthly mean. The study shows that the Dipole pattern has high positive (negative) correlation over the Northern (Southern) Tropical Atlantic region to sea surface temperature anomaly, precipitation anomaly and meridional component anomaly; high negative correlation to the zonal component over the Southern Tropical Atlantic region. It was also possible to see a heat gain (loss) during first (second) semester over Fortaleza’s region during positive Dipole events. On negative events, the opposite happens with higher percentages.