title: Solar rotation effects on the thermospheres of Mars and Earth.
abstract: The responses of Earth's and Mars' thermospheres to the quasi-periodic (27-day) variation of solar flux due to solar rotation were measured contemporaneously, revealing that this response is twice as large for Earth as for Mars. Per typical 20-unit change in 10.7-centimeter radio flux (used as a proxy for extreme ultraviolet flux) reaching each planet, we found temperature changes of 42.0 +/- 8.0 kelvin and 19.2 +/- 3.6 kelvin for Earth and Mars, respectively. Existing data for Venus indicate values of 3.6 +/- 0.6 kelvin. Our observational result constrains comparative planetary thermosphere simulations and may help resolve existing uncertainties in thermal balance processes, particularly CO2 cooling.
authors.affiliation: Department of Aerospace Engineering Sciences, University of Colorado, Boulder, CO 80309, USA. forbes@colorado.edu
authors.forename: Jeffrey M
authors.initials: JM
authors.lastname: Forbes
authors.forename: Sean
authors.initials: S
authors.lastname: Bruinsma
authors.forename: Frank G
authors.initials: FG
authors.lastname: Lemoine