Global impact on dust lifting by Martian dust devils

One of the most distinct aspects of the Mars environment is the presence of dust in the atmosphere. Dust significantly changes the atmospheric radiative properties and provides a potential feedback through altering the atmospheric winds and temperature structure. Moreover, a long term effect of a dusty atmosphere may be linked to geological features such as polar layer terrains, where layers of dust and sand are intertwined between layers of ice. However, the dust cycle involves several processes which are only partly understood, this is particularly so for injection of dust into the atmosphere, a process thought be dominated by near-surface wind stress lifting and by lifting by small convective vortices (dust devils). The uncertainties have a direct impact on the long term predictability of dust transport. We present results from a Martian global circulation model with both processes, here focusing on understanding the role played by dust devils.