Our planet is shaped by the interaction of living things with their physical environment. My interests center on understanding these interactions. Since I trained as an oceanographer, my primary expertise is in how the ocean circulates and influences marine life, climate, and atmospheric chemistry. I got my Ph.D. from the MIT/Woods Hole Joint Program in Physical Oceanography and spent over fifteen years in Princeton at Princeton University and NOAA’s Geophysical Fluid Dynamics Laboratory working to develop computer models of how the planet works. In January 2011 I joined the Department of Earth and Planetary Sciences at Johns Hopkins University. I took over from Tom Haine as department chair in July of 2018.
My group's research is currently focused in three major areas
1. Representing climate processes: Climate models try to faithfully represent physical and biological processes or their impacts. Areas of long-term interest include the representation of turbulence at scales ranging from centimeters to tens of kilometers, capturing the impacts of ocean color and understanding the controls on the growth of phytoplankton.
2. Understanding how these processes shape Earth's climate.I'm interested in the large scale circulation of the ocean and how it interacts with the biosphere and carbon cycle, as well as the role of aerosols such as mineral dust and black carbon.
3. Characterizing variability in the climate system. I'm interested in variability and change on a range of scales, from interannual variability associated with El Nino, to detecting biological and physical changes driven by anthropogenic climate change, to understanding multi-millennial variability in the carbon cycle.
More information on each of these topics can be found by clicking on the "Research areas" tab.
270.103: Introduction to Global Environmental Change and Sustainability
270.224: Oceans and Atmospheres (Spring semesters)
270.323: Ocean Biogeochemical Cycles (last taught Spring 2018)
270.325: Introductory Oceanography (Spring 2019)
270.327: Field Experience in Bermuda (Intersession 2018, 2019, focus on the ocean's role in the global carbon cycle)
270.425: Earth and Planetary Fluids (co-taught, fall semesters)
270.611: Advanced Atmospheric Dynamics (Last taught, Fall 2016)
270.620: Seminar in Geophysical Turbulence (Last taught,Fall 2015)
270.644: Physics of Climate Variability (Last taught, Fall 2014)
270.654: Environmental Data Analysis (Last taught, Fall 2017)
May 2019: Congratulations to graduating seniors Kaley Sten, Amy Chi and Cassidy Speller, of whom did research with the group (helping produce material for three manuscripts in total) during their time at JHU.
June 2019: Link to a popular article about our research on ocean color and climate change in Pacific Standard Magazine.
June 2019: Congratulations to Dr. Asha Jordan, who defended her Ph.D. thesis with Ben Zaitchik and myself on African dust and Sahelian precipitation.
