CLaSP Seminar Series - Dr. Orenthal Tucker
Date: March 30, 2017
Time: 3:30 pm - 4:30 pm
Location: Space Research Building Auditorium, Room 2246
Our guest for this week's CLaSP Seminar Series is Climate & Space research scientist Dr. Orenthal Tucker. Please join us!
Title: "Titan’s Escaping Atmosphere: Insights from Cassini"
Abstract: The Cassini mission has acquired a wealth of data on Titan's upper atmosphere during observations from over 100 Titan flybys. Vertical density profiles measured by the Ion Neutral Mass Spectrometer (INMS) indicate that the structure of the upper atmosphere is highly variable. In this seminar, I will discuss ideas on the capability of the interaction of precipitating ions from Saturn’s magnetosphere on driving such variability and current ideas on the neutral particle escape rate. The INMS density data can be roughly fit using several different energy distribution functions to describe the neutral gas densities (N2, CH4) in the transitional region of the upper atmosphere. These result in different conclusions on the thermal structure, energy deposition and escape.
I will discuss the results obtained from gas-kinetic models that can be relied upon to correctly interpret the dynamics implied by such fits of the density data. Since similar issues apply to the upper atmospheres of most planetary bodies, tests of simulations of the thermal structure and escape rates for Titan’s upper atmosphere, through which the Cassini spacecraft has made multiple passes, are critical.