A paper with Mark Marley as co-author entitled “Self-Consistent Model Atmospheres and the Cooling of the Solar System’s Giant Planets” was recently accepted for publication by the Astrophysical Journal. This paper is notable because it represents the completion of a project initiated by eminent SST scientist Jim Pollack before his death in 1994. At that time Pollack wanted to revisit a classic 1970’s era paper on the cooling of giant planets by Grossman and Graboske using modern physics, in particular by doing a better job of treating the atmospheric boundary condition. Pollack asked Marley to take on this project using the giant planet atmospheres code developed by Marley and SST scientist Chris McKay. Marley’s final meeting with Pollack a few weeks before his death was devoted to this project and Marley still has his notes from that meeting. At that time Pollack identified several challenges that would arise in the work, including the treatment of clouds.
Over the ensuing years Marley focused on the emerging fields of brown dwarf and extrasolar planet research and did not have a chance to return to Jim’s project. However many of the advances required to these new fields of study were highly relevant to the giant planet problem, including preparation of new opacity tables and a new cloud model developed by Marley and Andy Ackerman.
Ultimately Jonathan Fortney arrived at Ames as an NPP postdoc and began using and improving the giant planet atmosphere code which now included the Ackerman and Marley cloud treatment. Jonathan, now an assistant professor of astronomy at UCSC, used the code to compute boundary condition tables and combined these with his own giant planet evolution code. The resulting study of giant planet evolution is precisely the one originally envisioned by Jim Pollack sixteen years ago.