Abstract
As heavy particles fall towards windswept topography, their motion is governed partly by gravitational forces and partly by fluid forces resulting from the relative motion of the particles through the flow field. Topographically induced perturbations of the flow field distort particle paths and ultimately modify deposition patterns at the surface. Here, we calculate trajectories of particles falling toward a series of low‐amplitude hills. Particle motion is obtained by simplifying the dynamical equations of particle motion to kinematic form and then applying perturbation techniques. This simplification is possible when the timescale of fluid motions is much longer than the characteristic response‐time of the particles. It is shown that, under the right atmospheric conditions, alternating regions of convergent and divergent particle‐paths will occur. an extension of the trajectory analysis yields expressions that predict the point of surface impact as functions of the initial release point. This leads to a method for predicting the point along the surface where deposition is either a maximum or a minimum.