NOAA/WDS Paleoclimatology - Isla Los Testigos, Venezuela Coral Sr/Ca Data and SST from 1870-1995 CE

Sea surface temperature (SST) in the Tropical North Atlantic (TNA) ocean is a key component of the Atlantic Multidecadal Oscillation (AMO) and plays an important role in orchestrating hydroclimatic anomalies on adjacent continents. However, the narrow timespan of reliable instrumental SST records and the limited availability of paleoclimate SST records in the TNA region hinder our understanding of long-term TNA climate variability. Coral Sr/Ca has been extensively used as an SST proxy, allowing us to extend SST records into the pre-instrumental era. Here, we present replicated Sr/Ca records at bimonthly resolution from two Siderastrea siderea corals that grew offshore Isla Testigo Grande (Venezuela), spanning from 1871 to 1994 C.E. to evaluate SST variability in the TNA region. The reconstructed SST reflects TNA variability linked to regional hydroclimate extremes on nearby continents, including precipitation in Northeast Brazil and the Sahel, as well as decadal changes in hurricane activity. The multidecadal variability of reconstructed SST is coherent with instrumental records and paleoclimate reconstructions of the AMO, demonstrating its ability to represent the tropical component of the AMO. This suggests that the coral-based SST can serve as a valuable tool for investigating the consistency of the TNA and AMO relationship, potentially resolving disagreement among paleoclimate reconstructions in the pre-instrumental era. Overall, this study extends the Atlantic coral record further into the past and provides insights into the long-term interplay between TNA SST variability, the AMO, and tropical Atlantic climate.