High-angle wave instability and emergent shoreline shapes : 2. Wave climate analysis and comparisons to nature
Ashton, Andrew D.
Murray, A. Brad
MetadataShow full item record
Recent research has revealed that the plan view evolution of a coast due to gradients in alongshore sediment transport is highly dependant upon the angles at which waves approach the shore, giving rise to an instability in shoreline shape that can generate different types of naturally occurring coastal landforms, including capes, flying spits, and alongshore sand waves. This instability merely requires that alongshore sediment flux is maximized for a given deepwater wave angle, a maximum that occurs between 35° and 50° for several common alongshore sediment transport formulae. Here we introduce metrics that sum over records of wave data to quantify the long-term stability of wave climates and to investigate how wave climates change along a coast. For Long Point, a flying spit on the north shore of Lake Erie, Canada, wave climate metrics suggest that unstable waves have shaped the spit and, furthermore, that smaller-scale alongshore sand waves occur along the spit at the same locations where the wave climate becomes unstable. A shoreline aligned along the trend of the Carolina Capes, United States, would be dominated by high-angle waves; numerical simulations driven by a comparable wave climate develop a similarly shaped cuspate coast. Local wave climates along these simulated capes and the Carolina Capes show similar trends: Shoreline reorientation and shadowing from neighboring capes causes most of the coast to experience locally stable wave climates despite regional instability.
Author Posting. © American Geophysical Union, 2006. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Journal of Geophysical Research 111 (2006): F04012, doi:10.1029/2005JF000423.
Showing items related by title, author, creator and subject.
Response and impact of equatorial ocean dynamics and tropical instability waves in the tropical Atlantic under global warming : a regional coupled downscaling study Seo, Hyodae; Xie, Shang-Ping (American Geophysical Union, 2011-03-25)A regional coupled model is used for a dynamic downscaling over the tropical Atlantic based on a global warming simulation carried out with the Geophysical Fluid Dynamics Laboratory CM2.1. The regional coupled model features ...
Walker, Alison (Massachusetts Institute of Technology and Woods Hole Oceanographic Institution, 2001-03)Numerical solutions of the unstable, growing modes are found for the two-layer inviscid quasigeostrophic equations in a meridional channel. A steady mean flow in the N-S direction is imposed in the upper layer, and it ...
Insights on the OAFlux ocean surface vector wind analysis merged from scatterometers and passive microwave radiometers (1987 onward) Yu, Lisan; Jin, Xiangze (John Wiley & Sons, 2014-08-19)A high-resolution global daily analysis of ocean surface vector winds (1987 onward) was developed by the Objectively Analyzed air-sea Fluxes (OAFlux) project. This study addressed the issues related to the development of ...