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CONGRATULATIONS - THIS IS THE 100TH NJP VIDEO ABSTRACT! Please see our special 'Editor's Picks' playlist for our favourite video abstracts so far. Video abstract for the article 'A two-species continuum model for aeolian sand transport' by M Lämmel, D Rings and K Kroy (M Lämmel et al 2012 New J. Phys. 14 093037). Read the full article in New Journal of Physics at http://iopscience.iop.org/1367-2630/14/9/093037/article. GENERAL SCIENTIFIC SUMMARY Introduction and background. On a windy day at the beach, one can observe wind-blown clouds of sand grains meandering over the ground (see the animation below). A closer look reveals that the grains perform jumps of different height and length—a process called 'saltation'. Faster grains ricochet from the sand bed and eject other grains, while slower grains often get trapped in this bed after impact. This complex process is conveniently coarse-grained by dividing the whole ensemble of trajectories into two representative classes or 'species', so-called saltating and reptating grains. Main results. Our two-species approach allows for a very efficient analytical and numerical analysis of this ubiquitous phenomenon, which is to date still not completely understood. Linking the grain scale physics to the hydrodynamic transport properties, we were able to gain comprehensive qualitative and quantitative insights. We obtain a physically intuitive and quantitatively accurate model leading to a computationally simple flux law, which is in excellent agreement with wind tunnel measurements. Wider implications. Our model provides an appropriate starting point for numerous analytical and numerical investigations and applications ranging from structure formation at different scales, like sand ripples and dunes, to saltation-induced dust emission. These are important factors when addressing the problem of desertification or the influence of dust on the Earth's climate.