Research Topics:

Paleoclimatology, paleoceanography, deep-sea sediments, marine micropaleontology

Climate variability occurs on many different time scales – from the multi-thousand year glacial-interglacial cycles of the last 1.6 million years to the 3 to 5 year cycles of the El Niño-Southern Oscillation. Climate variability that occurs on very long time scales (10,000-100,000 years) is well-recorded in the geologic record, and the forcing mechanisms and climatic response on these types of time scales is reasonably well-understood (e.g., earth’s orbital variability and the Pleistocene ice ages). Climate variability on shorter time scales (interannual to millennial) is much less well-understood. Most geologic records are not of sufficient resolution, nor do they extend far enough into the past to be able to extract climate change information on these types of time scales.

Information is critically needed about the patterns and processes of climate change on sub-millennial time scales in order to help fill critical gaps in our understanding of the climate spectrum, especially as these are the time scales on which anthropogenic (human-induced) climate change is expected to occur. One of my research goals is to establish records of “baseline” climate variability against which we can compare modern climate change, and thus aid our ability to detect and predict human influences on global climate.

I am working on reconstructing the paleoclimate and paleoceanographic conditions that existed during the Quaternary Period using a variety of techniques, including micropaleontology, isotope geochemistry, and trace element geochemistry. My current emphasis is on decadal- to century-scale climate and ocean variability during the Holocene and late-Pleistocene. I currently have active research projects in the tropical Atlantic and subtropical Pacific oceans.

I am also interested in calibrating and developing new paleoclimate proxies. Comparing materials collected in sediment traps and high-resolution sediment cores to instrumental measurements of sea surface temperature, wind stress, ocean and atmosphere circulation, etc., allows us to groundtruth existing proxies and discover new ways to reconstruct past climate change.