A method to estimate the neutral atmospheric density near the ionospheric main peak of Mars

A method to estimate the neutral atmospheric density near the ionospheric main peak of Mars is introduced in this study. The neutral densities at 130 km can be derived from the ionospheric and atmospheric measurements of the Radio Science experiment on board Mars Global Surveyor (MGS). The derived neutral densities cover a large longitude range in northern high latitudes fromsummer to late autumn during 3Martian years, which fills the gap of the previous observations for the upper atmosphere of Mars. The simulations of the Laboratoire de Meteorologie Dynamique Mars global circulation model can be corrected with a simple linear equation to fit the neutral densities derived fromthe firstMGS/RS (Radio Science) data sets (EDS1). The corrected simulations with the same correction parameters as for EDS1match the derived neutral densities fromtwo other MGS/RS data sets (EDS2 and EDS3) very well. The derived neutral density from EDS3 shows a dust storm effect, which is in accord with the Mars Express (MEX) Spectroscopy for Investigation of Characteristics of the Atmosphere ofMarsmeasurement. The neutral density derived from theMGS/RSmeasurements can be used to validate the Martian atmospheric models. The method presented in this study can be applied to other radio occultation measurements, such as the result of the Radio Science experiment on board MEX.