Comparative Analysis of the Pluviometric Regime Between Dry and Rainy Years in the Piranhas Açu River Basin

Precipitation is one of the most important meteorological variables in climatic studies in the different regions of Brazil. Such importance is due to the consequences of what it can cause, when in excess or in deficiency for the productive sectors of the society. The objective of this study is to study the behavior of the pluviometric regime in the Piranhas- Acu river basin, located between the states of Paraiba and Rio Grande do Norte, between 1970 and 2015, and to analyze a rainfall quality in the rainy season of Some years dry and humid without identification intention a possible influence of the El Nino- Southern Oscillation (ENSO) in these years. As a main result, the pluviometric regime was characterized by a total annual average value of 247 mm, with a certain trend of increasing annual totals in recent years. In relation to the dry and humid years, it was observed that two years (1980 and 1984) presented conditions of neutrality in the Pacific Ocean, but rainfall in the rainy season were different: rainy and dry, respectively. This is because the dipole of the Atlantic Ocean Surface Temperature (SST) was favorable / unfavorable (negative / positive) to the rainfall, contributing / impairing rainfall quality in the FMA quarter of the region.