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Both summer and winter Atlantic Niño during the subsequent winter and spring 2.2. Extreme precipitation events on Southeast Tropical Atlantic (SETA) SST
events may be relevant to the predictability through their teleconnection to the ENSO the eastern edge of Northeast Brazil anomalies when SETA leads precipitation
of ENSO in the Pacific (Hounsou-Gbo et al., in the Pacific (HOUNSOU-GBO et al., 2019, for 4-6 months (Figure 2a). This positive
2020). However, the winter Atlantic Niño 2020). The results indicate that winter At- In June 2010, a succession of intense relationship shifts to the oceanic portion
has the advantage of being able to over- lantic Niño events influence the seasonal rainfall events gave rise to floods in the near the east coast of Brazil during the
come the ENSO predictability barrier before variability of South American precipita- eastern rivers of the states of Pernambuco rainy season, that is, in the warm pool of
spring, the so-called “spring barrier for tion in two ways. First, these events affect and Alagoas. The World Bank and Pernam- the southwest Atlantic (Figure 2b) (CINTRA
ENSO predictability”. However, the mech- spring rainfall in northern Northeastern buco government report (2010) recorded et al., 2015; SILVA et al., 2018), where the
anisms that explain this delayed oceanic re- Brazil (NNEB) through the evolution to the a total of 67 cities damaged, 20 deaths, signal from the South Equatorial Atlantic
sponse in the equatorial Pacific are still not southern tropical Atlantic mode (OKUMU- approximately 30,000 homeless and an Intertropical Convergence Zone (SITCZ)
well understood. The teleconnection be- RA and XIE, 2006; HOUNSOU-GBO et al., economic loss of more than US$ 1 billion. is strong (HOUNSOU-GBO et al., 2019).

tween the Atlantic and the Pacific is asso- 2020). Winter Atlantic Niño events also In that year, positive SST anomalies were These results support that SST anomalies
ciated with low frequency variability within influence South American precipitation recorded in the tropical southwest Atlan- are transported from the SETA region in
the two basins that is potentially modulat- through the connection with the following tic that exceeded 1 °C in relation to cli- boreal winter (November-January; NDJ)
ed by the Atlantic Multidecadal Oscillation year’s ENSO (HOUNSOU-GBO et al., 2020). matology between February and June, in westward to the NEB coast (Figures 2c, d,
(AMO). Recent studies indicate that AMO These results suggest the relevance of dif- the buoy of the Prediction and Research e) (HOUNSOU-GBO et al., 2015, 2019).
can modulate the multidecadal variability of ferent Atlantic Niño types for the 6-month Moored Array in the Tropical Atlantic – PI- Therefore, the interannual variability of
the Atlantic equatorial mode (MARTÍN-REY to 1-year predictability of ENSO and its RATA (BOURLÈS et al., 2019) located at SITCZ must be related to the shift of SST
et al. 2018), however, there are still several climate impacts, including the climate of 30°W and 8°S , as well as SST data from anomalies from east to west in the tropi-
uncertainties about the mechanisms that South America. the Advanced Very High-Resolution Radi- cal South Atlantic. When located near the
control the variability of the equatorial At- The influence of the positive/negative ometer (AVHRR, available at: http://ocean- east coast of the NEB, positive SST anom-
lantic on seasonal to decennial timescales. phase of the Atlantic interhemispheric watch.pifsc.noaa.gov). alies are associated with abnormally low
According to different authors, several mode and El Niño/La Niña is mainly strong Hounsou-Gbo et al., (2015, 2019) in- surface pressure, anomalous atmospheric
mechanisms contribute to the variability of over the northern part of the NEB in late vestigated how previous oceanic-atmo- cyclonic circulation at the surface, and an
the equatorial Atlantic. Some studies indi- boreal winter and early spring. In the east- spheric conditions (almost 6 months earli- upward vertical velocity at 500 hPa (Figure
cate that the Atlantic Niño variance main- ern part of the NEB (5°-11° S; 34.5°-37° er) in the tropical South Atlantic influence 2c). These latter conditions are favorable
ly depends on thermodynamic feedback, W), the rainy season, which peaks in the the climate of eastern NEB. They identified for more rain in the region. The opposite
while others argue that dynamic processes austral winter (May-July), is mainly linked a significant positive relationship between occurs during cooler years in the tropical
strongly contribute to the variability of the to events such as eastern wave disturbance eastern NEB precipitation anomalies and south Atlantic.
equatorial Atlantic (NNAMCHI et al., 2015; activities. that occur in the tropical South
JOUANNO et al., 2017). The meridional ad- Atlantic (KOUADIO et al., 2012; SILVA et
vection of SST anomalies from the North to al., 2018). The seasonal establishment of

the equator, the reflection of Rossby waves the second ITCZ located in the southern
at the western limit of the equatorial basin, equatorial region (GRODSKY and CARTON,
among other mechanisms, are indicated as 2003) also coincides with the peak of the
responsible for the Niño Atlantic variability rainy season in the east of the NEB. Con-

(LÜBBECKE and MCPHADEN, 2012; LÜB- vergence in the southern ITCZ is associated
BECKE et al., 2018). with atmospheric convection and rainfall
Summer Atlantic Niño events indirectly over the warm waters of the Southwest
impact South American rainfall variability Atlantic warm pool in June-July.

402 BLUE ECONOMY Ocean and Climate: New Challenges 403