Research program
Our goal is to understand how the climate system works and how it has evolved over a wide range of time scales and forcing scenarios — in Earth’s past and into the future.
These questions can only be fully answered by considering the entire Earth system at once, which calls for a broad, interdisciplinary research program. Our work bridges atmosphere and ocean dynamics, (paleo-)climatology and glaciology. We use a hierarchy of numerical models — from idealized models to fully coupled, state-of-the-art Earth system models — together with theory, across many temporal and spatial scales. That breadth is what the name “Earth System Dynamics Lab” stands for.
Climate modeling
Climate models are an invaluable tool for detailed studies of the factors that control the observed circulation. They also let us study past climate states and project how the climate system will evolve under climate change. Much of our work uses the Community Earth System Model (CESM2), including its coupling to the Community Ice Sheet Model.
This video shows an application of nested grids in CESM2 (courtesy of Dr. Adam Herrington, NCAR).
- Model development & optimization
- Model hierarchies
- Ice sheet–climate coupling
- Model biases
Dynamic meteorology
We study the processes and interactions that shape regional to planetary-scale atmospheric circulation: flow–topography interactions, diabatic heating, and complex internal wave dynamics — including stationary waves, Rossby-wave breaking, critical-layer reflection and wave guides.
- Flow–topography interactions
- Rossby-wave dynamics
- Jet streams & storm tracks
- Climate–ice sheet interactions
Paleoclimate dynamics
Our work has improved understanding of the interactions between the atmospheric circulation and evolving ice sheets over the last glacial cycle. The continent-wide Laurentide Ice Sheet at the Last Glacial Maximum (LGM) was extreme not only in size but in its influence on the planetary-scale circulation. While smaller pre- and post-LGM ice sheets had a fairly limited influence, the LGM ice sheet promoted stationary-wave breaking and reflection, producing a strong, zonally oriented North Atlantic jet stream and storm track — with large implications for the evolution of the Eurasian ice sheet. The growth of the North American ice sheet, in contrast, was more strongly controlled by local atmosphere–ice sheet interactions.
- Last Interglacial
- Last glacial inception
- Last Glacial Maximum
- Late Pliocene warm period
- Arctic gateways
Research interests
Numerical modeling
Model development and optimization; model hierarchies and applications; biases in climate and circulation models, from idealized and simplified models to comprehensive general circulation models.
Dynamic meteorology & climatology
Midlatitude and large-scale circulation regimes; stationary waves; flow–topography interactions; Rossby-wave breaking; critical-layer reflection; wave guides; jet stream and storm track dynamics; atmosphere–ocean–land–ice sheet interactions; sea-level rise from melting polar ice sheets; climate feedbacks; katabatic winds.
Paleoclimatology
Atmospheric and oceanic circulation in warm and cold climates; the LGM and pre-LGM glacial climate; interaction between continental-scale ice sheets and the time-mean circulation; conditions for glacial inception; Arctic gateways and North Atlantic climate; jet streams and storm tracks in past climates.