Reconciling divergent histories of Eastern Pacific climate with new coral data from Galapagos (Ecuador)

University Of Arizona, Tucson AZ

Investigators

Abstract

The El Niño (ENSO) system orchestrates climate variability and extremes worldwide, and its behavior under greenhouse warming remains one of the largest uncertainties in anticipating future climate change. ENSO has a dramatic impact on the climate of the Galapagos Islands, and this impact is preserved in paleoclimate records from the archipelago. But published paleoclimate records from the Galapagos yield disagreeing versions of the islands' recent climate history, including the magnitude of recent warming and the range and timing of ENSO variability. To resolve these disagreements, this project will develop reconstructions of regional sea surface temperature using the isotope geochemistry of long-lived, annually banded corals. With these records, which directly track ocean conditions, important questions about recent climate variability and change in this iconic region can be addressed. For example, is the Galapagos warming as fast as the rest of the world? What is the history of El Niño variability in the region? Do changes in this region coincide with periods of higher-latitude climate variability such as cooler ("Little Ice Age") conditions between 1500-1850? Understanding the full range of ENSO variability and ongoing trends is important locally, for improving conservation planning and climate adaptation efforts in the Galapagos National Park and Marine Protected Area. The results of the research will be useful across many disciplines, from conservation management in Galápagos to evaluation of global climate models. Funding also supports student education and training at the graduate and undergraduate level.