Influence of the modes of climate variability in the Tropical Pacific and Atlantic on accumulated rainfall and reservoir water volumes in the Northeast Brazil

Abstract

The volumes of artificial reservoirs as well as the accumulated rainfall over the Northeast region of Brazil (NEB) are sensible to the modes of climate variability. Thus, the objective of this study is to identify the relationship between the spatial patterns of the modes of climate variability in the Tropical Atlantic and Pacific Oceans, and the homogeneous rainfall subregions affecting the recharge of the water volumes of reservoirs in the NEB during the period from 1986 to 2018. For this end, we used monthly rainfall; monthly water volume data for artificial reservoirs; sea surface temperature anomalies in the Tropical Pacific and Tropical Atlantic Ocean. The first step was to apply cluster analysis to subdivide the NEB according to the monthly rainfall climatology. After, the technique of synthetic maximum rainfall series was applied. Then, the response time between rainfall climatology and reservoir water volume climatology was identified by means of cross‐correlation. Finally, the partial least squares regression was applied to infer the relationship between synthetic maximum rainfall series in each subregion and the modes of climate variability. Results showed that five homogeneous rainfall subregions with three distinct wet seasons. The synthetic time series of rainfall in the subregions were positively correlated with the climatology of the reservoir volumes with lags of up to 5 months after the beginning of the series. Both rainfall and the water volume of artificial reservoirs were sensible to the modes of climate variability of the studied oceans.

A New Look into the South America Precipitation Regimes: Observation and Forecast

“…In general, cluster analysis studies of precipitation in SA regions use hierarchical methods [78,[80][81][82]85,87,[89][90][91][92][93][94][95][96][97][98][99], given that these techniques provide satisfactory results and have a variety of clustering methods and several dissimilarity metrics to categorize the variables into homogeneous groups [91]. Considering the non-hierarchical method, the few existing studies in SA examine specific regions of the continent, such as Bolivia [79], Argentina [83], Chile [84], and Ecuador [86].…”

“…So, there is still a gap in the literature for redoing this work with statistical methods, such as cluster analysis. Until now, studies involving a precipitation clustering process focused only on specific regions of the continent, such as the tropical SA [78], Bolivia [79], Argentina [80][81][82][83], Chile [84], Colombia [85], Ecuador [86], Brazil [87,88], and Brazilian sectors, such as the northeast [89][90][91][92][93][94], south and southeast [95][96][97], central-west [98], and the Amazonian portion [99]. In this scenario, the present study's relevance is justified not only for identifying homogeneous rainfall regions in SA considering a recent period (1993-2016) and an objective methodology but also by evaluating the skill of last generation climate predictions provided by ECMWF for South American continent.…”

The dependence of hydropower planning in relation to the influence of climate in Northeast Brazil

“…Reductions in streamflow are strongly related to meteorological conditions and land use. For example, rainfall reductions of up to 35% proportionally impacted streamflow rates [ 10 , 35 ]. Thus, cluster analysis suggests reductions in rainfall of 22.9% at latitude 9°, 13.3% at latitude 12° and 12.9% at latitude 13°, according to S3 Fig with highlighting to latitude 9°South.…”

Meteorological droughts and water resources: Historical and future perspectives for Rio Grande do Norte state, Northeast Brazil

“…Similar approach was done by Medeiros et al . (2018) to Castanhão, Engenheiro Armando Ribeiro Gonçalves, and Coremas, the biggest reservoirs of the Ceará, Rio Grande do Norte and Paraíba states, respectively, and also by Gomes and Lima (2021) for several reservoirs in NEB.…”