General research interests

We live in a changing environment. The focus of my research is to place ongoing changes in the context of natural variability, using mainly paleoclimate and long instrumental records. I am particularly interested in tropical climate systems such as the El Niño/Southern Oscillation (ENSO) and monsoons, which orchestrate patterns of climate change over large, even global, reaches yet are poorly understood in terms of their natural range of variability and their sensitivity to global forcings and background conditions. I am also interested in the paleoclimate record of the Southwestern US, in particular the recurrence of decadal and longer "megadroughts." Most of my work on tropical systems utilizes geochemical records from long-lived corals, and I am increasingly involved in cave- and lake-based paleoclimate work as well. I maintain active field programs that include students and colleagues. In addition to generating primary paleoclimate data from these archives, I also work on projects that synthesize or compare available paleoclimate records of many types (along with instrumental records and climate model output) to draw broader conclusions about past changes. Finally, my work on reefs as paleoclimate archives has led to an expanded interest in documenting the human impact on reefs, using paleoenvironmental methods to look closely at the past few centuries.

The above map shows sites where I am working (active or recently active). More details on active research projects can be accessed at the links below:

-tropical ocean variability from corals

-Southwest drought records from caves

-Holocene paleoclimate records from tropical lakes

-paleoclimate synthesis projects

I am grateful to the National Science Foundation (CAREER, ATM, MRI, HSD, and ESH), the National Oceanic and Atmospheric Administration (CPO/CCDD), and the University of Arizona for support of my research programs.