The proposed work will test and apply a new technique for reconstructing sea surface temperature (SST) at seasonal resolution using coral skeletons. The technique, called Rayleigh-based multi-element (RBME) thermometry, uses multiple element ratios to isolate the SST signal from other factors affecting coral skeleton composition. To quantify the method?s accuracy and reproducibility, RBME thermometry will be used to reconstruct SSTs from four species of modern extra-tropical and tropical Atlantic corals in ~50-year sections for which instrumental temperature records are available. The technique will then be applied to fossil corals of the same four species to generate seasonal-scale SST records for the coldest period of the Little Ice Age (1650?1700). These records will lead to an improved understanding of the amplitude and spatial distribution of SST change in the Atlantic during a climate anomaly that is not fully understood.
This research will advance our capacity to reconstruct past changes in the ocean?climate system, and thereby to understand how this system may change in the future. The project will enhance research infrastructure by developing computer code to make the RBME technique accessible to the broader scientific community. A graduate student will be supported through the WHOI/MIT Joint Program, and undergraduate students will be involved via WHOI?s Summer Fellowship, Winter Internship, Minority Fellowship, and Guest Student programs.