Strong ENSO Forcing of Wet Season Rainfall Extremes in the Eastern Amazon

Recent years have seen strong droughts and floods in the Amazon basin, the largest center of atmospheric convection on land. To assess to what degree these events are extreme in a historical perspective requires accurate and long-term climate data, which are generally lacking for this part of the world. Here, we developed a 131-year oxygen isotope chronology from exactly dated tree rings of Cedrela odorata from the eastern Amazon Basin. The chronology (1885–2016) correlates strongly with observed wet-season rainfall totals (r = −0.71, 1951–2016) and stream discharge over the eastern equatorial Amazon. In contrast to oxygen isotope chronologies further inland that record basin-wide rainfall, our new record provides a good rainfall proxy for the eastern Amazon basin alone and shows that extreme precipitation events are also driven by ENSO.<p></p>