Assessing the Environmental Forcing of 40 Years of Sandbar Migrations at the Field Research Facility, Duck, NC
Abstract
Sandbars are a ubiquitous morphologic feature found on beaches throughout the world, modifying wave dissipation and nearshore hydrodynamics. The coastal community has placed considerable emphasis on developing predictive capabilities for the temporal behavior of sandbars. Previous works have identified geometric relationships and geologic controls over observed interannual net offshore migration trends, and shorter-term studies have clearly identified that in general larger/smaller waves drive offshore/onshore migrations occurring in the weather-band time-scale. Modeling studies tailored to reproduce daily to weekly migrations have identified dependencies on a range of parameters, but notably contain many tuning parameters such that models containing distinctly different physics can reproduce the same sandbar translations. In this study, we assess whether a 40 year record of monthly sandbar surveys and coupled wave observations can provide insights to the forcing that drives cross-shore dynamics. A clustering analysis composed of complex empirical orthogonal functions and hierarchical clustering identifies frequent morphologic states present within the offshore progression of sandbars derived from 600+ cross-shore profiles surveyed at the Field Research Facility in Duck, NC. Trends in the wave characteristics driving transitions between these morphologic states are assessed using global average conditions, extremes associated with storms, and non-dimensional parameters.
- Publication:
-
AGU Fall Meeting Abstracts
- Pub Date:
- December 2020
- Bibcode:
- 2020AGUFMEP066..06A
- Keywords:
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- 1625 Geomorphology and weathering;
- GLOBAL CHANGE;
- 3020 Littoral processes;
- MARINE GEOLOGY AND GEOPHYSICS;
- 4315 Monitoring;
- forecasting;
- prediction;
- NATURAL HAZARDS;
- 4217 Coastal processes;
- OCEANOGRAPHY: GENERAL