Earth

Earth’s surface climate is controlled by atmospheric dynamics. For example, the atmospheric transport of heat, angular momentum, and water vapor controls the distributions of surface temperatures, surface winds, and precipitation. Most atmospheric transport is accomplished by macroturbulence —turbulence with length scales measured in thousands of kilometers, strongly affected by both planetary rotation and the thermal stratification of the atmosphere. So any theory of climate must build upon a theory of atmospheric macroturbulence.

We use observational data and simulations to develop theories of how atmospheric dynamics—particularly macroturbulence—shape large-scale climatic features. Questions we are addressing include: How do storminess and precipitation change as atmospheric greenhouse gas concentrations increase? How do monsoons and the intertropical convergence zone respond to the changes in insolation that accompany variations in Earth’s orbit around the sun? How does cloudiness change with climate, and how does that amplify or dampen the climate system’s response to perturbations? Theories answering such questions help us understand and interpret the changes in the atmospheric climate that occurred not only over our planet’s history, but that are likely to occur in the future.

Our goal, in short, is to develop a set of fundamental physical laws governing climate.

Both an introductory lecture on Grand Challenges in Climate Dynamics, which summarizes some of our past and ongoing research on Earth’s climate, as well as a Watson Lecture on Where the Wind Comes From, with a historical perspective, are available on our Talks video page.

Other Planets

Physical laws governing atmospheric dynamics should be general enough to apply not only to Earth, but to other planets as well. Although our ability to observe and simulate the atmospheres of other planets is limited, explaining what we do know about these atmospheres provides an intellectual adventure into distant worlds, testing our understanding of atmospheric dynamics.

The sparseness (or newness) of data about other planets means that explanations of their climate dynamics must have a firm basis in theories. It also means that we can focus on the “biggest picture” questions: How did the jets on the giant planets come about? Why are there methane lakes on Titan—but only at its poles? What temperature and precipitation patterns can be expected on an Earth-like, tidally locked exoplanet?

Our research in this area helps interpret both ground-based and space-based observations, as well as providing constraints on what future space missions may find.