Recent paleoclimatic studies suggest that changes in the tropical rainbelt across the Atlantic Ocean during the past two millennia are linked to a latitudinal shift of the Intertropical Convergence Zone (ITCZ) driven by the Northern Hemisphere (NH) climate. However, little is known regarding other potential drivers that can affect tropical Atlantic rainfall, mainly due to the scarcity of adequate and high-resolution records. In this study, we fill this gap by reconstructing precipitation changes in Northeastern Brazil during the last 2,300 years from a high-resolution lake record of hydrogen isotope compositions of plant waxes from the core Boqc0901 dated by Viana et al . (2014). We present isotope carbon and hydrogen plant waxes of n-C28 alkanoic acid, the percentage of C3 plants and hydrogen isotope reconstruction of precipitation. We find that regional precipitation along the coastal area of South America was not solely governed by north-south displacements of the ITCZ due to changes in NH climate, but also by the contraction and expansion of the tropical rainbelt due to variations in sea surface temperature and southeast trade winds in the tropical South Atlantic Basin.

Boqc0901, a 90-cm-long core, was collected in a water depth of 8.2 m near the center of lake. This core was sampled in the field by slicing into 0.5-cm sections that were stored in plastic bags. The age-depth model was based on fifteen calibrated 14CAMS dates (https://doi.pangaea.de/10.1594/PANGAEA.897629) on bulk organic matter by Viana et al. (2014).PIRE NSF-FAPESP: 2017/50085-3CAPES: 99999.012754/2013-07NSF Dimensions-Biota FAPESP: 2013/50297FAPESP: 2016/15807-5US National Science Foundation NSF: AGS-1303828US National Science Foundation NSF: OISE-1743738US National Science Foundation NSF: 1103403

Supplement to: Utida, Giselle; da Cruz Junior, Francisco William; Etourneau, Johan; Bouloubassi, Ioanna; Schefuß, Enno; Vuille, Mathias; Novello, Valdir Felipe; Prado, Luciana Figueiredo; Sifeddine, Abdelfettah; Vincent, Klein; Zular, André; Viana, João Cláudio Cerqueira; Turcq, Bruno Jean (2019): Tropical South Atlantic influence on Northeastern Brazil precipitation and ITCZ displacement during the past 2300 years. Scientific Reports, 9(1), 1698