Abstract

Abstract. As spacecraft missions return ever more data from Mars, additional tools will be required to explore and analyse these datasets efficiently. To streamline research into the atmosphere of Mars, a user-orientated modelling capability is developed that enables automatic initialisation and running of a column model. As a demonstration we utilise the modelling framework to provide additional verification for the University of Helsinki and Finnish Meteorological Institute Mars column model temperature profiles above the height of typical lander meteorological measurements, i.e. above 2 m. We utilise the framework at landing site locations that are well characterised to understand the model's applicability and to identify future opportunities for modifications to the framework. We do this by using the framework to compare the column model to temperature soundings made by the Mars Reconnaissance Orbiter. We find that the column model, without any modification, is able to reproduce the observed lapse rates and average temperatures closely in most cases except for a 20–60 K increase over the northern hemisphere mid-winter. We can reproduce this discrepancy by incorporating an adiabatic heating term into the column model. Fitting of the modified column model to the observations results in estimated maximum downward vertical wind velocities of ∼ 10 cm s−1 at altitudes of 15–20 km over the winter solstice at the VL-1 and VL-2 sites. The approach developed here may possibly provide a way to independently estimate or observe the vertical motion in the Martian atmosphere. However, even though the magnitude of the vertical wind speed appears reasonable, it is not clear at this point how much the atmospheric heating is due to other mechanisms such as advection. We have introduced new application software that can quickly find and display the requested data and can be immediately analysed using the included tools. We have demonstrated the potential of this type of software application with a glimpse into the upper atmosphere of Mars.

Highlights

  • Observational data are being returned from Mars in ever increasing quantities by spacecraft

  • It is apparent though that column model, soundings and Mars Climate Database (MCD) are in broad agreement with the observations

  • The column model was initialised with data from the soundings observations

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Summary

Introduction

Observational data are being returned from Mars in ever increasing quantities by spacecraft. At particular times of the year and at certain locations, the atmosphere deviates from radiative equilibrium, e.g. during the northern hemisphere winter, as warm air is generated by adiabatic compression in the descending arm of the meridional circulation (Heavens et al, 2011). This can create a significant temperature inversion up to an altitude of between 10 and 20 km at middle to high latitudes. The polar orbit enables MCS to acquire one morning (∼03:00 LTST, Local True Solar Time) and early afternoon (15:00 LTST) sounding from each latitude and longitude on Mars

Background
Description and operation of the framework
Adiabatic heating modification for the column model
Verification of the column model
Atmospheric circulation probed with the column model
Concluding remarks
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