Professor Geoffrey Vallis
May 16, 2013 (Thursday)
7:00-8:00, Kane Hall 210
Dr. Geoffrey K. Vallis
Senior Scientist and Professor in the Program in the Atmosphere and Oceanic Sciences and NOAA's Geophysical Fluid Dynamics Laboratory at Princeton University
Lecture: "Timescales and Uncertainties in Climate Change"
Online lecture registration is closed.
About the Lecture
Our planet is warming, and much of that warming is due to the burning of fossil fuels; this much we know. Yet there is much we do not know, and putting bounds on these uncertainties is critical if we are to avoid, or justify, either the alarmist or complacent tendencies that are simultaneously found in abundance in society. We also need to better appreciate the timescales on which the planet will warm as we burn fossil fuels, and then will cool down after we have burnt all the fuel. Some recent arguments suggest that global warming will not be as bad in the short term as sometimes portrayed, but may nevertheless be much worse than anticipated in the long term. But what exactly is the 'short term' and what is the 'long term'? And how certain can we be about any of this? If the answer is 'not very', should we even care about the long term?
About the Speaker
Professor Vallis' work varies between basic research in geophysical fluid dynamics and more applied modeling of various aspects of the ocean, atmosphere, or climate, although distinguishing between these subfields can sometimes be quite arbitrary. A common feature of his work is trying to use basic theory in conjunction with more complete numerical models to come to a more well-rounded understanding of phenomena than can be achieved with a single approach.
On the oceanic side, much of his recent work has been devoted toward trying to understand the three-dimensional structure of the wind-and-buoyancy-driven circulation, and in particular the thermocline. The effects of ventilation (or subduction), diffusion and mesoscale eddies all play a role, and disentangling their sometimes competing effects involves the use of both numerical models and theory. He's now trying to understand the ocean’s role in climate change--how does the ocean absorb heat in a warming planet?
On the atmospheric side, he's recently been looking at the nature of variability at timescales from a week to a season, and how this might be caused by the interaction of baroclinic eddies. Again, a complete understanding of this involves bringing together areas as seemingly diverse as the theory of geostrophic turbulence, wave-meanflow interaction, and general circulation modeling of the atmosphere.
Sponsored by Department of Atmospheric Sciences.