Climate Science Speaker Monday, October 20, 2014 Stephen Griffies

Climate Science Speaker
Monday, October 20, 2014
Stephen Griffies, NOAA Geophysical Fluid Dynamics
Title: Elements of Sea Level in a Changing Climate
In this talk, we survey the physics of global and regional sea level, with a focus on how sea level
has changed in the past century and may change in the future. We start by exploring global mean
sea level changes arising from ocean heating (thermosteric sea level rise) and from changes to
the ocean mass. Regional sea level variations can be large relative to the global mean, meaning
they are a primary concern for sea level impacts. Examples of such regional variations include
fluctuations due to natural modes of climate variability (e.g., Pacific Decadal Variability, North
Atlantic Oscillation, Atlantic Meridional Overturning Circulation), and from mass redistributions
that alter the earth's gravity field. Scenarios for future global mean sea level changes typically
include an upward trend due to ocean warming. Less certain is our ability to project changes
involving ice sheets. We conclude the talk by describing a mechanism for potentially large ice
sheet melt arising from projected changes in Southern Ocean winds and the associated
shallowing of relatively warm coastal currents circling Antarctica.
Stephen Griffies is a senior research scientist at NOAA's Geophysical Fluid Dynamics Laboratory (GFDL)
in Princeton, NJ. His education includes a PhD in physics, masters in applied math, and bachelors in
chemical engineering. After a three-year post-doc at Princeton University's Geosciences Program, he
joined the GFDL staff in 1996. His research centers on aspects of the ocean's role in the global climate
system, both from a fundamental process perspective and large-scale climate perspective. A recent
focus of his work involves the study of global and regional sea level fluctuations/trends, which
forms the topic of his talk.
All talks will be held in Kline Geology Laboratory
Auditorium, Room 123 at 2 pm