Influence of Amazonia Rainfall on equatorial Atlantic SST variability – In honor Mark Cane’s Legacy

In mid-1980s, Prof. Mark Cane suggested Atlantic Niños as my graduate research topic. Four decades later, I would like to present our research on this topic to honor Mark’s guidance and inspiration since the beginning of my career. Although the influence of tropical Atlantic on rainfall over Amazonia has been studied extensively, the influence of Amazonia on the Atlantic Ocean has received little attention. We will present observational evidence to show that convectively coupled Kelvin Waves (CCKW) propagated from Amazonia, modulated by land surface condition and regional circulation, play a leading role in generating westerly wind anomalies over the equatorial Atlantic during boreal spring (March-May). The resulting Bjerknes/thermocline feedback contributes to a warmer annual maximum SST in boreal spring and so a stronger seasonal cycle over the eastern equatorial Atlantic than over the eastern Pacific. The interannual variation of rainfall over Amazonia in boreal spring also subsequently influence that of the equatorial Atlantic SST in June-August, contributing to the onsets of Atlantic Niños and Niñas.