Exploring the climate problems of Brazil’s Nordeste: a review

Abstract

This article reviews the exploration of the climate dynamics of Brazil's Nordeste in the course of a century. The drought-prone and semi-arid northern Nordeste of Brazil experiences a short rainy season around March-April, when the interhemispheric gradient of sea surface temperature (SST) in the tropical Atlantic is weakest and the Intertropical Convergence Zone (ITCZ) reaches its southernmost position in the course of the annual cycle. The recurrent Secas (droughts) have a severe socio-economic impact. During drought years, the interhemispheric SST gradient in the tropical Atlantic is steep and the ITCZ stays far North, while the waters of the eastern equatorial Pacific tend to be anomalously warm. Based on the extensive diagnostic exploration of the circulation mechanisms of interannual climate variability, empirical methods have been developed for the forecasting of the Nordeste rainy season. These have been applied in the real-time prediction of seasonal rainfall anomalies throughout the last decade of the 20th century.

An Analysis of Rainfall Extremes in the Northern South America and Their Behaviors for Future Climate Based on A1b Scenario

“…These results were obtained for the DJF trimester. Considering conclusions pointed out by Hastenrath (2012) regarding the importance of the precipitation in the months previous to the peak of the rainy season in the NEB region associated with a favorable SST gradient in the Tropical South Atlantic and in the Tropical Eastern Pacific oceans, it may be a positive feature for the end of the century.…”

“…According to Marengo et al (2013a) and Espinoza et al (2013), however, the events were attributed to different dynamical phenomena. Furthermore, these extreme climate conditions have subjected the inhabitants of the Amazon and Northeast regions to great economic losses (TOMPKINS et al, 2009;HASTENRATH, 2012;MARENGO et al, 2013b;MARENGO AND BERNASCONI, 2015;. Over the past half-century, the Amazon basin has experienced severe droughts and floods more frequently than normal, which has been confirmed by river level measurements (GLOOR et al, 2013;SATYAMURTY et al, 2013).…”

“…Espinoza et al (2013) examined the 2012 flood and showed that it was caused by the coincident peak of the 2 northward tributaries of the Amazon River reaching their maximum discharge in April 2012 (see also GLOOR et al, 2013). As with previous floods (1986, 1993 and 1999), the 2012 event was attributed to a La Niña episode.As part of the climate variability in Brazilian northeast region, drought are much more frequent due to the characteristic semi-arid / arid climate which is predominant in that area (annual rainfall can vary from 2000 mm to 700 mm from the cost to the western of the region (HASTENRATH, 2012;MARENGO AND BERNASCONI, 2015), neighboring the east of AMZ region). Exacerbated use of the natural resources, soil degradation and a decrease in the total amount of rainfall over the years are some of the factors that enhance the already high probability of extensive droughts in the region (MARENGO AND BERNASCONI, 2015;.…”

“…As part of the climate variability in Brazilian northeast region, drought are much more frequent due to the characteristic semi-arid / arid climate which is predominant in that area (annual rainfall can vary from 2000 mm to 700 mm from the cost to the western of the region (HASTENRATH, 2012;MARENGO AND BERNASCONI, 2015), neighboring the east of AMZ region). Exacerbated use of the natural resources, soil degradation and a decrease in the total amount of rainfall over the years are some of the factors that enhance the already high probability of extensive droughts in the region (MARENGO AND BERNASCONI, 2015;.…”

Variabilidade espacial da sazonalidade da chuva no semiárido brasileiro

“…A disponibilidade natural de água na região Semiárido do Brasil é caracterizada por uma distribuição de chuvas bastante irregular, baixos índices de pluviosidade e longos períodos de estiagem (Nys & Engle, 2014;Hastenrath, 2012). Os longos períodos de estiagem, influenciados pelo El Niño (Hastenrath, 2012;Cavalcanti, 2012), ocasionam danos irreparáveis à população da região, em especial àqueles que retiram seu sustento da atividade agrícola, em especial a agricultura familiar (Rodriguez et al, 2015). Os diferentes sistemas de circulação atmosférica que atuam nessa região tornam a climatologia complexa, refletindo em uma grande variabilidade climática, considerando as chuvas, com eventos de precipitação variando no tempo e no espaço (Silva, 2004).…”