Tendências do controle climático oceânico sob a variabilidade temporal da precipitação no Nordeste do Brasil

Abstract

Given the significant differences in spatial and temporal distribution of rainfall, prolonged periods of water stress, problematic soils and absence of perennial rivers, the Northeastern interior is the region most vulnerable to climate change in Brazil. Based on analysis of climate data, this study aims to identify trends in sea surface temperatures in the North Atlantic, South Atlantic, East Pacific and Central Pacific Oceans and their relation with the temporal variability in precipitation in Pernambuco in recent periods. Three methods were used to achieve the proposed objective. The Rain Anomaly Index was used as evidence of the relationship between the oceans and rainfall in NEB. Research trends in TSM's the Mann-Kendall method. To demonstrate changes in current precipitation, climate indices suggested by the Expert Team on Detection, Monitoring and Climate Change Indices were used. The climate change indices indicated that changes in rainfall patterns have been occurring, with a tendency toward an increase in the volume of rain (with the exception of the eastern coast) and more concentrated seasonal distributions. Statistical analysis of TSM's on the Pacific and Atlantic allowed us to observe that there is a warming trend and that when analyzed alone, the occurrence of positive anomalies over the eastern Pacific (El Niño) and negative anomalies over the South Atlantic (positive dipole), droughts are more severe, based on analysis of the rainfall anomaly index. Also based on the IAC, we concluded that when both events occur in isolation they exert influence on rainfall in the region, however, when they act together this influence is more pronounced, changing the behavior of the general circulation of the atmosphere meridionaly (Hadley cell) and zonally (Walker cell).