Seminar: CPS Seminar
date: 2017 July 18(Tue)15:00-
room: CPS Seminar room
speaker: Naoki Terada (Associate Professor,Tohoku University Graduate School of Science)
organizer: Yoshiyuki Takahashi
title: Thermal escape of planetary atmospheres - revisited
abstract: Recent progresses in satellite observations and theoretical works have demonstrated that our understanding of thermal escape of planetary atmospheres, in particular its escape rates (diffusion-limited escape rates) and transition among different escape regimes (Jeans escape, slow hydrodynamic escape, and hydrodynamic escape), is insufficient. Some theoretical works have pointed out that Mars could not have maintained its atmosphere during first several hundred million years due to intense thermal escape, therefore quantitative estimates of thermal escape rates and transition among different escape regimes (in addition, effects of non-thermal escape) are required to better understand the long-term evolutions of total amount and redox state of planetary atmospheres. In this seminar, effects of atmospheric gravity waves on the thermal escape rates will be discussed based on recent MAVEN observations and full-particle (DSMC) simulations.
keywords: Thermal escape of atmospheres, Mars, Gravity waves