气候变化领域集成服务门户(CCPortal): A Numerical Investigation of Wave-Supported Gravity Flow During Cold Fronts Over the Atchafalaya Shelf

CCPortal

DOI	10.1029/2019JC015269
	A Numerical Investigation of Wave-Supported Gravity Flow During Cold Fronts Over the Atchafalaya Shelf
	Zang Z.; Xue Z.G.; Xu K.; Ozdemir C.E.; Chen Q.; Bentley S.J.; Sahin C.
发表日期	2020
ISSN	21699275
卷号	125 期号:9
英文摘要	Wave-supported fluid mud (WSFM) plays an important role in sediment downslope transport on the continental shelves. In this study, we incorporated WSFM processes in the wave boundary layer (WBL) into the Community Sediment Transport Modeling System (CSTMS) on the platform of the Coupled Ocean-Atmosphere-Wave-and-Sediment Transport modeling system (COAWST). The WSFM module was introduced between the bottommost water layer and top sediment layer, which accounted for the key sediment exchange processes (e.g., resuspension, vertical settling, diffusion, and horizontal advection) at the water-WBL and WBL-sediment bed boundaries. To test its robustness, we adapted the updated model (CSTMS + WBL) to the Atchafalaya shelf in the northern Gulf of Mexico and successfully reproduced the sediment dynamics in March 2008, when active WSFM processes were reported. Compared with original CSTMS results, including WSFM module weakened the overall intensity of sediment resuspension, and the CSTMS + WBL model simulated a lutocline between the WBL and overlying water due to the formation of WSFM. Downslope WSFM transport resulted in offshore deposition (>4 cm), which greatly changed the net erosion/deposition pattern on the inner shelf off the Chenier Plain. WSFM flux was comparable with suspended sediment flux (SSF) off the Atchafalaya Bay, and it peaked along the Chenier Plain coast where wave activities were strong and the bathymetric slope was steep. The influence of fluvial sediment supply on sediment dynamics was limited in the Atchafalaya Bay. Sensitivity tests of free settling, flocculation, and hindered settling effects suggested that sediments were transported further offshore due to reduced settling velocity in the WBL once fluid mud was formed. Although sediment concentration in the WBL was sensitive to surface sediment critical shear stress, cohesive bed behavior was less important in WSFM dynamics when compared with strong hydrodynamic during cold fronts. ©2020. American Geophysical Union. All Rights Reserved.
语种	英语
来源期刊	Journal of Geophysical Research: Oceans
文献类型	期刊论文
条目标识符	http://gcip.llas.ac.cn/handle/2XKMVOVA/186686
作者单位	Department of Oceanography and Coastal Sciences, Louisiana State University, Baton Rouge, LA, United States; Now at Woods Hole Oceanographic Institution, Woods Hole, MA, United States; Center for Computation and Technology, Louisiana State University, Baton Rouge, LA, United States; Coastal Studies Institute, Louisiana State University, Baton Rouge, LA, United States; Department of Civil and Environmental Engineering, Louisiana State University, Baton Rouge, LA, United States; Department of Civil and Environmental Engineering, Northeastern University, Boston, MA, United States; Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA, United States; Department of Civil Engineering, Yildiz Technical University, Istanbul, Turkey
推荐引用方式 GB/T 7714	Zang Z.,Xue Z.G.,Xu K.,et al. A Numerical Investigation of Wave-Supported Gravity Flow During Cold Fronts Over the Atchafalaya Shelf[J],2020,125(9).
APA	Zang Z..,Xue Z.G..,Xu K..,Ozdemir C.E..,Chen Q..,...&Sahin C..(2020).A Numerical Investigation of Wave-Supported Gravity Flow During Cold Fronts Over the Atchafalaya Shelf.Journal of Geophysical Research: Oceans,125(9).
MLA	Zang Z.,et al."A Numerical Investigation of Wave-Supported Gravity Flow During Cold Fronts Over the Atchafalaya Shelf".Journal of Geophysical Research: Oceans 125.9(2020).