Possible Influence of the Oceanic-Atmospheric Climatic Phenomenon El Niño Southern Oscillation (ENSO) on the Monthly Accumulated Precipitation in Campos dos Goytacazes, RJ, Brazil

Abstract

This study is based on the hypothesis that there is some relationship between the oceanic-atmospheric climatic phenomenon El Niño Southern Oscillation (ENSO) and the climate behavior in the municipality of Campos dos Goytacazes, located in the north of the state of Rio de Janeiro, Brazil, in relation to the values of accumulated monthly rainfall of this locality. For this, six stations distributed in the municipality of Campos dos Goytacazes, RJ, were analyzed, being one climatological station and five rainfall stations. It was hypothesized that there would be some relationship between the monthly cumulative precipitation values and the occurrence of ENSO events. For this study, the database provided by NOAA was used, where it is possible to observe SST values in the south-eastern portion of the Pacific Ocean, in order to identify the periods of occurrence of the oceanic-atmospheric phenomenon ENOS and to relate them with climatological data of monthly accumulated precipitation in the municipality of Campos dos Goytacazes, RJ, provided by two online platforms: Meteorological Database for Teaching and Research (in Portuguese, Banco de Dados Meteorológicos para Ensino e Pesquisa - BDMEP), developed by the National Institute of Meteorology (INMET); and HidroWEB, developed by the National Water Agency (in Portuguese, Agência Nacional de Águas - ANA). Finally, a spreadsheet was elaborated with the purpose of relating the periods of more intense ENSO events with a distribution of monthly accumulated precipitation value in the six climatological stations mentioned previously, having as temporal cut the period between the years of 1961 and 2016. After an analysis of these data using statistical methods, it was realized that, at the beginning, it was not possible to obtain clear evidence of the relationship between the occurrence of ENOS phenomenon and the behavior of the values of accumulated monthly precipitation in Campos dos Goytacazes/RJ, in this temporal cut, although the result of the trend line of the dispersion diagram pointed to higher values of accumulated monthly rainfall occurring during episodes of La Niña. However, studies should continue to be carried out for a better understanding of ENSO and its possible effects in the Southeastern Brazilian region, since this possible relationship is still not very clear for the scientific community.