Journal of Geophysical Research: Earth Surface
Rhythmic patterns are common features in nature. Prominent examples are the patterns formed on the interface of a mobile sandy bed and turbulent flow, due to currents, tides, wind waves or other forcing mechanisms. These bed patterns or bed forms vary in both spatial and temporal scales, from small-scale bed ripples (spacing on the order of centimeters) to large-scale tidal sand banks (spacing on the order of 5 km). In this paper and in this special issue, we focus on a cluster of large-scale features, i.e., marine sand waves and river dunes, occurring in rivers, estuaries and seas all over the world.