Evolution of High Latitude Climate During the Plio-Pleistocene Transition

In collaboration with Dr. Timothy Herbert, my former PhD advisor from Brown University, I have endeavored to provide the first systematic look at the relationships between the growth of large northern hemisphere ice sheets, regional and global trends in ocean surface temperature and productivity, and the variability of ocean surface conditions driven by changes in Earth’s orbit. This work was funded by NSF in 2006.  During the past several years, numerous Lafayette EXCEL scholars: Joanna Morabito’08, Hilary White ’10, Laura Bocher ’10, Sean Murphy ‘ 10, Alex Brannick ’11 and Chris Kelly ’13 have contributed to this research endeavor. Working in close collaboration with Tim and his graduate students and undergraduate students at Brown we have generate a series of paleoclimate records which have allowed us to:

  1. examine the rates of ocean cooling and the timing of major temperature changes during the Plio-Pleistocene transition (in both the Northern and Southern Hemispheres);
  2. document the pattern of Plio-Pleistocene ocean productivity changes and explore potential mechanisms to explain those changes;
  3. evaluate the relationship between our records and other climate indicators on both long (>1 million year timescales) and orbital timescales (timescales on which the Earth’s position in its orbit relative to the sun change the distribution of solar energy on the Earth’s surface and thus the climate).

To frame these newly generated data in context, I have started collaborations with Dr. Yair Rosenthal of Rutgers University and his former Ph.D. student Dr. Sindia Sosdian and Dr. Daniel Sigman of Princeton University.  Work the Yair and Sindia, which was recently published in Earth and Planetary Science Letters, took a detailed look at the evolution of a suite of North Atlantic climate variables on both secular and orbital time scales.