Research Interests

I am particularly interested in the mechanisms by which tropical processes both influence and respond to global change on seasonal to centennial timescales -- and vice versa.  Are there well-defined and predictable cycles driven by unique physical mechanisms?  Or do the oceans, land surface, biota, ice and stratosphere simply integrate and retain a "memory" of well-understood mechanisms underlying month-to-month and year-to-year variations?  The answer to this question is important for the development of probabilistic and regional climate change projections and uncertainty estimates into the 21st century.

Our perspective on this problem is from paleoclimatic observations, modeling and synthesis activities.

Paleodata acquisition
Proxy system modeling
Paleoclimate reconstruction
Paleoclimatic synthesis
Student and Postdoc Opportunities
Paleodata acquisition: Development of  high resolution proxy climate observations from regions sensitive to various phenomena of interest.  We have primarily focused on the tropics and coupled ocean-atmosphere dynamics associated with ENSO.  Thanks to support from NSF's MRI and EAR/I&F programs, a new stable isotope laboratory has recently been commissioned at the University of Maryland, Department of Geology.  We are developing paleoclimate records from tropical trees lacking annual rings, massive coral colonies, fish otoliths, forams and mollusc shells using high resolution, high throughput continuous flow methods to improve signal replication.  More about the stable isotope laboratory is here. Anchukaitis and Evans (2010)
Proxy system modeling:  Modeling of the processes by which environmental conditions are sensed by proxy systems and imprinted on the archives on which we make paleo-observations.  With funding from NSF/P2C2 and NOAA/C2D2, we are exploring simple but realistically multivariate and/or nonlinear models for oxygen isotopic composition in tropical trees and corals, and ring width and density in trees.  We are using these models as diagnostic tools for understanding the origin of long-term variations in actual observations, and as weak constraints in paleoclimate data assimilation exercises.  Tolwinski-Ward et al (2011);
                click for pdf and see also Erratum
Paleoclimate reconstruction:  Validated reconstruction of  regional and global climate fields from sparse observational networks of paleoproxy data and statistical and/or physical models of the climate system.   Current NSF/P2C2 and NOAA/C2D2 collaborative research includes investigation of multivariate calibration, ensemble reduced space objective analysis climate field reconstruction, pseudoproxy analysis of reconstruction uncertainties, comparison of reconstructed fields with general circulation model output, Bayesian hierarchical modeling, and state space intercomparison of the results.  Smerdon et
                al (2011); click for pdf
Paleoclimate synthesis: Are paleoclimate simulations, which are the result of climate system models driven with realistically hypothetical external radiative forcing, consistent with paleo-observations, which are the result of the actual climate system driven by actual external radiative forcing?  If so (given uncertainties), what are the principal mechanisms by which the actual climate can be inferred to have varied in the past (and into the future)?  In work with the PAGES/Ocean2k project, we are comparing multimodel superensembles of simulations for the past 1-2 millennia with community-built syntheses of marine paleodata and paleoreconstructions to address this question.   Thompson et al (2012); click for pdf
Interested in paleoclimatological research opportunities?  group 2013: Kaitlyn, Alex,
              Grace, Mike, Becca, Emily (missing: Grant, Christina,
              Leah)Contact me for more information about possible student and postdoctoral projects in tropical isotope dendroclimatology, statistical reconstruction of paleoclimatic fields, proxy system modeling, and paleoclimate synthesis and dynamical analysis.  I hold faculty or affiliate appointments, advise students and serve on committees in Geology , ESSICAtmospheric Sciences and Applied Math and Scientific Computing at Maryland.  I hold adjunct positions at Lamont-Doherty and Arizona.  We collaborate widely in the paleoclimate community.  More information on graduate studies at UMD/Geology is here.  Learn more about my teaching and mentoring philosophy and interests, and past and current student research projects, from my online teaching portfolio.

Last updated 2 Apr 2015.