International audienceWe describe the horizontal distribution of hydrogen density at the exobase of Mars as simulated by coupling a 3D GCM with an exospheric balistic model, taking into account the flight balistic time of the exopheric hydrogen atoms. Such a description is more realistic than the assumptions used in our past study [4]. We simulate 4 Martian rotations at three different seasons. The horizontal variations of the hydrogen density at the exobase are reduced when the exospheric balistic transport is included compared to our previous simulations