COMBINED TEMPERATURE-PRECIPITATION MODES AND THEIR RELATIONSHIP WITH LARGE-SCALE CLIMATE INDICES IN PARANÁ, SOUTHERN BRAZIL (1980-2014)

Resumo

In recent decades the Northeast of Brazil experienced several episodes of intense droughts while other regions were affected by heavy rainfall events that caused severe flooding. The variability of temperature and precipitation in Brazil are associated with large-scale climatic indices, such as the El Niño Southern Oscillation (ENSO), the Multidecadal Atlantic Oscillation (AMO) and the Tropical North Atlantic (TNA). In this study, quantiles 25 and 75 of temperature and precipitation were used to determine the climatic trends in terms of number of days for the different modes (warm and dry, warm and humid, cold and dry or cold and wet). Subsequently, correlation analyzes were carried out with nine different climatic indices that influence the regional climate of southern Brazil. Our results highlighted the absence of a dominant mode throughout the seasons and over the years. We also found spatio-temporal trends in this region. In addition, except for the warm-dry mode where 8 out of 10 stations were correlated with the Niño1 + 2 index, there were few correlations between the modes and the different climate indices used in this research. Despite the increasing temperature trends, and a complex and heterogeneous variations in precipitation regime, our results did not indicate any significant changes in the modes nor their relationship with the climate indices.