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Roles of Wind‐Driven Currents and Surface Waves in Sediment Resuspension and Transport During a Tropical Storm
Author(s) -
Xie Xiaohui,
Li Ming,
Ni Wenfei
Publication year - 2018
Publication title -
journal of geophysical research: oceans
Language(s) - English
Resource type - Journals
eISSN - 2169-9291
pISSN - 2169-9275
DOI - 10.1029/2018jc014104
Subject(s) - shoal , estuary , sediment , sediment transport , bay , oceanography , geology , storm , sedimentary budget , wind wave , hydrology (agriculture) , sedimentary rock , current (fluid) , environmental science , geomorphology , geotechnical engineering , paleontology
Satellite remote sensing shows two hot spots of high suspended sediment concentration during the passage of Hurricane Irene (2011) over Chesapeake Bay: the shallow shoals in the mid Bay and the area around the mouth of the estuary. A coupled ocean wave sediment transport model is used to investigate mechanisms driving sediment resuspension and transport during the storm. The model reproduces the observed spatial variations of suspended sediment concentration and surface wave heights in the estuary and shows that both wave‐ and current‐induced shear stresses are important in stirring bottom sediment. In the mid‐Bay region, large wave‐induced shear stress causes sediment resuspension on the shallow shoals, while wind‐driven currents advect the suspended sediment downstream. Around the mouth of the estuary, the combined action of large waves and strong outflows produces high suspended sediment concentration, resulting in the export of ~0.8 Mt of estuarine sediments to the shelf. The storm‐induced sediment resuspension and export could be an important term in the sedimentary budget of an estuary.