title: On the formation of current ripples.
abstract: For grain sizes finer than coarse sand, the first flow-transverse bedforms to develop are current ripples. Although numerous studies have analysed different aspects of bedform morphodynamics, to date no comprehensive physical explanation for the formation of ripples has been given. We offer such an explanation based on a virtual boundary layer concept, and present a model predicting ripple height on the basis of grain size, current velocity and water depth. The model contradicts the conventional view of current ripples as bedforms not scaling with flow depth. Furthermore, it confirms the dependence of ripple dimensions on grain size, and their relative insensitivity to flow strength.
authors.affiliation: Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK-1305 Copenhagen, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Bartholdy
authors.affiliation: Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK-1305 Copenhagen, Denmark.
authors.forename: V B
authors.initials: VB
authors.lastname: Ernstsen
authors.affiliation: Marine Science Department, Senckenberg Institute, Suedstrand 40, 26382 Wilhelmshaven, Germany.
authors.forename: B W
authors.initials: BW
authors.lastname: Flemming
authors.affiliation: MARUM, University of Bremen, Leobener Strasse, 28359 Bremen, Germany.
authors.forename: C
authors.initials: C
authors.lastname: Winter
authors.affiliation: Marine Science Department, Senckenberg Institute, Suedstrand 40, 26382 Wilhelmshaven, Germany.
authors.forename: A
authors.initials: A
authors.lastname: Bartholomä
authors.affiliation: Department of Geosciences and Natural Resource Management, University of Copenhagen, Øster Voldgade 10, DK-1305 Copenhagen, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Kroon