Search Publications
Boulder abundances and size-frequency distributions on Oxia Planum-Mars: Scientific implications for the 2020 ESA ExoMars rover
Quantin, Cathy; Pajola, Maurizio; Carter, John +4 more
This paper presents the abundances and the size-frequency distributions (SFD) of boulders identified on a sector of the prime landing site for the ExoMars 2020 rover, in Oxia Planum region. By means of a HiRISE image, boulders ≥ 1.75 m across have been identified and subdivided according to the two main Oxia Planum geological units: the Noachian c…
On the link between martian total ozone and potential vorticity
Holmes, James A.; Lewis, Stephen R.; Patel, Manish R.
We demonstrate for the first time that total ozone in the martian atmosphere is highly correlated with the dynamical tracer, potential vorticity, under certain conditions. The degree of correlation is investigated using a Mars global circulation model including a photochemical model. Potential vorticity is the quantity of choice to explore the dyn…
A deep search for the release of volcanic gases on Mars using ground-based high-resolution infrared and submillimeter spectroscopy: Sensitive upper limits for OCS and SO2
Villanueva, G. L.; Mumma, M. J.; Tokunaga, A. T. +1 more
Recent volcanic activity has long been considered a distinct possibility that would place major constraints on the evolution of Mars' interior. Volcanic activity would result in the outgassing of sulfur-bearing species. As part of our multi-band search for active release of volcanic gases on Mars, we looked for carbonyl sulfide (OCS) at its combin…
Diurnal variation in martian dust devil activity
Lewis, S. R.; Chapman, R. M.; Balme, M. +1 more
We show that the dust devil parameterisation in use in most Mars Global Circulation Models (MGCMs) results in an unexpectedly high level of dust devil activity during morning hours.
Prior expectations of the diurnal variation of Martian dust devils are based mainly upon the observed behaviour of terrestrial dust devils: i.e. that the majority…Modelled isotopic fractionation and transient diffusive release of methane from potential subsurface sources on Mars
Stevens, Adam H.; Lewis, Stephen R.; Patel, Manish R.
We calculate transport timescales of martian methane and investigate the effect of potential release mechanisms into the atmosphere using a numerical model that includes both Fickian and Knudsen diffusion. The incorporation of Knudsen diffusion, which improves on a Fickian description of transport given the low permeability of the martian regolith…
The Martian dust devil electron avalanche: Laboratory measurements of the E-field fortifying effects of dust-electron absorption
Farrell, W. M.; Collier, M. R.; McLain, J. L. +1 more
Analogous to terrestrial dust devils, charged dust in Mars dust devils should become vertically stratified in the convective features, creating large scale E-fields. This E-field in a Martian-like atmosphere has been shown to stimulate the development of a Townsend discharge (electron avalanche) that acts to dissipate charge in regions where charg…