My research focuses on the oceanographic changes in the Eastern Tropical Pacific over the last millennium. The Eastern Tropical Pacific is the center of action for the El Niño Southern Oscillation (ENSO), and changes in variability of the ENSO system in the last 1000 years is of keen interest to the climate community. I study these changes by looking at the stable isotope signature of individual Globigerinoides ruber foraminifera, a mixed-layer dwelling foram. I look at the oxygen isotopic ratio (δ18O), which reflects surface (or near surface) oceanographic conditions, carbon isotopic ratio (δ13C), which can be reflective of nutrient load, water source, and atmospheric CO2 isotope changes; and at Mg/Ca ratios, which relate to sea surface temperatures (SSTs).
The goal of my research is to determine whether changes in sea surface variability are systematic, and if the observed changes are related to changes in solar and volcanic tropical forcing. There is a good amount of basic science involved, including the creation of a new, continuous and novel proxy record from individual foraminifera. Given the sampling interval and sedimentation rate of the core, I have had the opportunity to compare core-top samples with oceanic reanalysis data to determine the fidelity of an individual foraminifera-based proxy which provides calibration and validation of the method.
My research continues with the current set of results spanning the last 1000 years, as the results so far have been quite promising. In the future, I would like to analyze the next 1000+ years, extending this record back beyond the Roman Climate Optimum using materials already processed and ready for analysis.
