کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
6388192 | 1627764 | 2014 | 17 صفحه PDF | دانلود رایگان |
![عکس صفحه اول مقاله: Current-wave interaction in the Mississippi-Atchafalaya river plume on the Texas-Louisiana shelf Current-wave interaction in the Mississippi-Atchafalaya river plume on the Texas-Louisiana shelf](/preview/png/6388192.png)
- Including the waves' effects significantly modifies the Mississippi-Atchafalaya plume structure and the stratification.
- Including the waves' effects identify two dynamically distinct regions: the Chenier shelf and the Louisiana Bight.
- Wave enhanced bottom stress dominates over the Chenier shelf, and traps more freshwater to the nearshore region.
- The surface intensified wave mixing and 3D wave forces dominate over the Louisiana Bight, and weaken the stratification.
- One way coupling is capable of resolving the majority of wave effects over the Texas-Louisiana shelf.
Wave-current interaction over the Texas-Louisiana shelf, and its effects on the dispersal and mixing of the Mississippi-Atchafalaya river plume, have been investigated using the Coupled Ocean-Atmosphere-Wave-Sediment Transport (COAWST) Modeling System. The modeling system is driven by realistic wave and current conditions at the open boundaries and high frequency1-D wind measured from a nearby meteorological station. Skill analysis demonstrates that the model reproduces the wave and salinity fields reasonably well. Waves over the Texas-Louisiana shelf are dominated by locally forced wind seas, and generally propagate in the same direction as the winds. Investigation into the spatial differences in the effect of waves reveals two distinct dynamical regions: the Chenier shelf, the shelf region extending roughly offshore from Sabine Lake to Vermilion Bay, and the Louisiana Bight, the region between the Mississippi Delta and Terrebonne Bay. A variety of model runs are performed, where specific wave processes are either included or excluded, in order to isolate the processes acting in different regions. The Chenier shelf is mainly affected by wave enhanced bottom stress, whereas the Louisiana Bight is mostly affected by the surface wave induced mixing and 3-D wave forces. The wave enhanced bottom stress suppresses cross-shore exchange, and acts to trap more freshwater in the nearshore regions shallower than 50Â m over the Chenier shelf. Wave enhanced bottom stress plays only a minor role in the Louisiana Bight, where the surface-trapped Mississippi plume rarely feels the bottom. The surface intensified wave mixing and 3-D wave forces reduce the surface salinity and weaken the stratification in the region associated with the thin recirculating Mississippi plume in the Louisiana Bight. Model results indicate that the surface wave mixing, the 3-D wave forces, and the wave bottom stress exhibit little interaction over the Texas-Louisiana shelf. Finally, we have demonstrated that the one-way coupling is capable of resolving the majority of wave effects over the entire shelf if the seasonal scale is of interest.
Journal: Ocean Modelling - Volume 84, December 2014, Pages 67-83