Synoptic environment associated with heavy rainfall events on the coastland of Northeast Brazil

Abstract

Abstract. Northeast Brazil (NEB) has an extensive coastal area, often hit by natural disasters that bring many social and economic losses. The objective of this work was to study the synoptic environment associated with a heavy rainfall event (HRE) on the coastland of NEB. We used daily rainfall data for coastal area of NEB between the states of Rio Grande do Norte and Bahia, divided into two subregions: north and south coastland. This data was obtained from the hydrometeorological network managed by the Agência Nacional de Águas and the daily data reanalysis from the ERAInterim. For the selection of HRE the technique of quantiles was used, thus defined HRE where at least one rain gauge recorded rainfall above 95th percentile. The interannual distribution of events showed occurrence maximum in La Niña years and minimal in El Niño years. The results suggest that the HRE were formed mainly due to the action of upper-level cyclonic vortex, in hight levels, and due to the action to South Atlantic convergence zone, in low levels.

Influence of the Tropical Atlantic Ocean’s Sea Surface Temperature in the Eastern Northeast Brazil Precipitation

“…Most of the studies highlight the NNEB in relation to the adjacent oceans analyzing the ITCZ, weather system that determines the rainy season of this region. However, there is an increasing interest in understanding the dynamic of precipitation occurrence in the ENEB region [10]- [20] [21], since it is in this region that most of the NEB population is concentrated and in where the most extreme precipitation events occur in the region [22]. In this study the main objective is to analyze the precipitation in ENEB from April to June and the processes of ocean-atmosphere interaction, mainly the episodes of GRAD_S.…”

Linear trend of occurrence and intensity of heavy rainfall events on Northeast Brazil

“…There are few researches on the HRE climatology in Brazil, although there are important scientific efforts about the South America (Haylock et al , ) and about the regions South and Southeast Brazil (Teixeira and Satyamurty, ). On NEB, the researches are few (Oliveira et al , , ) and the results are concerning to studies of global data analysis (Groisman et al , ) or in local scope studies (e.g. Santos and Manzi, ).…”

Assessing Homogeneity and Climate Variability of Temperature and Precipitation Series in the Capitals of North-Eastern Brazil

“…Studies for NEB include the analysis of rainfall characteristics (Rao and Hada, 1990;Rao et al, 2016), trends of (heavy) rainfall events (Oliveira et al, 2012(Oliveira et al, , 2013Priscilla et al, 2014), drought and connected vegetation dynamics (Barbosa et al, 2006(Barbosa et al, , 2015Marengo and Bernasconi, 2015), trends of maximum and minimum temperature (da Silva, 2004), or the tendency of wind speed (Alexandre and Santos e Silva, 2013). Vincent et al (2005) describe changes in the temperature extremes in South America for the period 1961-2000 that are particularly pronounced for climate indices related to minimum temperature, while those based on maximum temperature reveal no consistent changes.…”