TY - JOUR
T1 - Shorter estuarine dunes and upstream migration due to intratidal variations in stratification
AU - van der Sande, W.M.
AU - Roos, P.C.
AU - Gerkema, T.
AU - Hulscher, S.J.M.H.
N1 - Funding Information:
This research is funded by the Simon Stevin Meester prize, The Netherlands (awarded by NWO to S.J.M.H. Hulscher) and the Perspectief Program Saltisolutions, The Netherlands , which is financed by NWO Domain Applied and Engineering Sciences in collaboration with private and public partners. We thank Henk Schuttelaars for helpful discussions on the estuarine circulation.
Publisher Copyright:
© 2023 The Author(s)
PY - 2023/2/5
Y1 - 2023/2/5
N2 - Estuarine dunes are large-scale subaqueous rhythmic bed patterns, and differ from river dunes and marine sand waves in that they exist in environments characterized by several estuarine-specific processes. One of these processes is the tidally varying salinity stratification, with stratified conditions inhibiting vertical mixing. This causes an asymmetry between ebb and flood tide, leading to the strain-induced circulation. Here, we show through a morphodynamic linear stability model that reduced turbulent mixing in partially mixed environments leads to significantly shorter dunes compared to well-mixed environments. Furthermore, intratidal variations in stratification are a driver of upstream migration of dunes due to the tidal straining circulation. Our results constitute one explanation for differing dune wavelengths between two positions in the Elbe estuary. This study stresses the importance of (variations in) stratification for estuarine dunes, and hence improves our understanding of dune characteristics.
AB - Estuarine dunes are large-scale subaqueous rhythmic bed patterns, and differ from river dunes and marine sand waves in that they exist in environments characterized by several estuarine-specific processes. One of these processes is the tidally varying salinity stratification, with stratified conditions inhibiting vertical mixing. This causes an asymmetry between ebb and flood tide, leading to the strain-induced circulation. Here, we show through a morphodynamic linear stability model that reduced turbulent mixing in partially mixed environments leads to significantly shorter dunes compared to well-mixed environments. Furthermore, intratidal variations in stratification are a driver of upstream migration of dunes due to the tidal straining circulation. Our results constitute one explanation for differing dune wavelengths between two positions in the Elbe estuary. This study stresses the importance of (variations in) stratification for estuarine dunes, and hence improves our understanding of dune characteristics.
KW - Morphodynamic modeling
KW - Estuarine dunes
KW - Strain-Induced Periodic Stratification (SIPS)
KW - UT-Hybrid-D
U2 - 10.1016/j.ecss.2023.108216
DO - 10.1016/j.ecss.2023.108216
M3 - Article
SN - 0272-7714
VL - 281
JO - Estuarine, coastal and shelf science
JF - Estuarine, coastal and shelf science
M1 - 108216
ER -