Caitlin Griffith

Professor

Ph.D., 1991, State University of New York, Stony Brook

Years with LPL: 2002 to present

Astrobiology, Exoplanets; Planetary Formation and Evolution, Planetary Astronomy, Planetary Atmospheres, Planetary Surfaces, Titan & Outer Solar System

Dr. Griffith investigates the chemical, dynamical and thermal structures of planetary atmospheres, using ground-based and spacecraft observations. The data are interpreted with radiative transfer calculations to measure the temperature, composition and dynamical signatures of planetary atmospheres. These results are analyzed with simple chemical, radiative and dynamical models to address questions on atmospheric structure and evolution. Dr. Griffith also works with mathematical methods to analyze large astronomical data bases. This work involves Principal Component Analyses and basic Artificial Intelligence techniques.    

Dr. Griffith has worked extensively to understand Titan, Saturn’s largest moon. Titan resembles Earth, as it sports, rain, rivers, storms and seas. However, on Titan, methane plays the role that water plays on Earth. Yet, how Titan evolved to its current state is not understood. The ultraviolet radiation from the Sun irreversibly destroys methane, the by-products of which form a thick atmospheric haze, which ends up as organic sediments on Titan’s surface. There is no obvious source to supply the atmosphere with methane, except from the evaporation of methane from the polar lakes. But the methane in the lakes and Titan’s atmosphere, and will be exhausted in soon by geological time scales.  One open question is where does the CH4 come from? Work by Dr. Griffith supports the idea that subsurface methane furnishes Titan's CH4 atmosphere, and thus the organic-rich atmosphere.  The communication between the surface and the interior plays a major role on Earth and, likely on Titan. Yet without understanding of the history of Titan, it is not clear whether prolonged production of complex organics, sourced by subterranean reservoirs, are common in cool CH₄-rich exoplanetary atmospheres.  

Dr. Griffith also investigates the structures and compositions of giant planets and extrasolar planets. She finds that these efforts are complementary as we can gain much more detailed information on planets in our Solar System, which are not possible for exoplanets.