The Impact of Inherited Morphology on Sandbar Migration During Mild Wave Seasons

Abstract

Sandbars are ubiquitous morphologic features found in the nearshore environment throughout the world, yet predictive capabilities of their evolution remain limited. In order to provide new insights on the relevant processes controlling sandbar morphodynamics, this study uses a 41‐year record of 637 monthly cross‐shore profiles from Duck, North Carolina, USA, to derive complex empirical orthogonal functions representative of the two dominant modes of sandbar migrations: offshore and onshore propagation. Interference of these two modes produces commonly observed sandbar states. While mild wave energies are traditionally assumed to drive onshore sandbar migration, the offshore mode is repeatedly seen to dominate sandbar migration in mild wave seasons following anomalously high late‐winter wave energy and when the inherited morphology is composed of a single bar or terrace, as opposed to a more common two‐bar state. A data‐derived conceptual model is presented synthesizing the effect of antecedent morphology and wave climate chronology on interannual trends in net offshore sandbar migration.

Document Details

Document Type
Pub Defense Publication
Publication Date
Feb 02, 2023
Source ID
10.1029/2022gl101219

Entities

People

  • A. Spicer Bak
  • Bradley Johnson
  • Dylan Anderson
  • Katherine Brodie
  • Nicholas Cohn
  • Patrick J. Dickhudt

Organizations

  • United States Army Corps of Engineers

Tags

Readers

  • Atmospheric Science / Meteorology, specifically Wind Wave Turbulence.
  • Coastal Oceanography