Research

The overarching motivation for my research is to document the history of, and understand mechanisms of climate change. As the ocean plays a key role in climate, a full understanding of the complexity of past climate change requires thorough knowledge of variations in ocean hydrography (e.g., seawater temperature, salinity and heat content) and circulation through time. Throughout my career, I have endeavored to develop new geochemical proxies that offer quantitative information of past ocean properties and thus the possibility for rigorous paleoceanographic reconstructions in a similar manner to that conducted with modern data.

My research over the past decade has primarily focused on three topics: 1) Proxies development; 2) Cenozoic climate transitions with an emphasis on the Antarctic and Northern Hemisphere glaciations; and 3) Holocene climate variability in the equatorial Pacific and high latitudes. In pursuit of these interests, I have developed a comprehensive field and lab programs. These include several coring cruises (e.g., Hawaii, 1998; Indonesia, 2003; Norwegian Sea, 2004; Cape Hatteras, 2004; New Zealand, 2005; Timor Sea, 2005; eastern equatorial Pacific, 2009; Western Pacific warm pool, 2013) that, as discussed below, have generated significant new insights into paleoclimate processes. These research activities resulted in ~90 peer reviewed articles of which 3 were published in Nature and 4 in Nature Geo Science and 9 in Science magazine (and the 10th accepted pending revisions). Based on the ISI web of Science my papers were cited by ~2800 papers with H factor of 33 (July 2014).

My emphasis on hands-on lab experience and an active field program has also greatly contributed to the education and training of junior scientists. My lab has been a training ground for a number of post-docs and students and helped in establishing new analytical procedures for the broad paleoceanographic community. To date I have advised 7 graduate students and 13 post docs, many of them are holding positions in academic and research institutes. Below I highlight my main achievements in these fields.

In the near future I plan to continue with, and expand on the investigation of climate variability in the equatorial Pacific and high latitudes with the objectives of understanding the controls on and role of ocean heat content on centennial and longer time scales. Likewise, we will continue with our research on hydroclimate variability in the western equatorial Pacific. As conventional cores provide only limited time coverage to test some of the questions discussed below, I have recently developed an ocean drilling program in the western equatorial Pacific. The new program (IODP Expedition 363) is scheduled to sail at the end of 2016 and I believe will provide new insights into the warm pool climate variability with unprecedented resolution. Likewise, I am in the process of developing another drilling proposal for the North Atlantic to expand our research there.

I am also continuing research into the climate of the warm Pliocene and the processes leading to the Northern Hemisphere Glaciation (NHG) and mid-Pleistocene Transition. As the most recent period with similar apparently conditions with those predicted for the near future, it is important to understand the climate conditions at that time interval. The new cores from expedition 363 will likely augment our current work. I hope that these will allow us to improve our ability for long-term reconstructions of ocean temperatures in the very near future.