Extreme bed shear stress during coastal downwelling

Kämpf, Jochen

doi:10.1007/s10236-019-01256-4

Cited by 5 publications

(2 citation statements)

References 43 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…A further consequence of enhanced subsurface near‐inertial currents driven by the land‐sea breeze is the contribution of elevated bed shear stresses toward the resuspension of seabed sediment. The inertial oscillation‐induced bed shear stresses would act in conjunction with those induced by surface gravity waves and also subinertial subsurface currents, which can be particularly enhanced during downwelling events (Kämpf, 2019). This process may further contribute to phytoplankton productivity in coastal upwelling systems through the introduction of regenerated nutrients (produced by benthic recycling) into the water column (Fanning et al., 1982; Herbert, 1999).…”

Section: Discussionmentioning

confidence: 99%

Enhanced Vertical Mixing in Coastal Upwelling Systems Driven by Diurnal‐Inertial Resonance: Numerical Experiments

et al. 2020

View full text Add to dashboard Cite

The land‐sea breeze is resonant with the inertial response of the ocean at the critical latitude of 30°N/S. 1‐D vertical numerical experiments were undertaken to study the key drivers of enhanced diapycnal mixing in coastal upwelling systems driven by diurnal‐inertial resonance near the critical latitude. The effect of the land boundary was implicitly included in the model through the “Craig approximation” for first‐order cross‐shore surface elevation gradient response. The model indicates that for shallow water depths (<∼100 m), bottom shear stresses must be accounted for in the formulation of the “Craig approximation,” as they serve to enhance the cross‐shore surface elevation gradient response, while reducing shear and mixing at the thermocline. The model was able to predict the observed temperature and current features during an upwelling/mixing event in 60 m water depth in St Helena Bay (∼32.5°S, southern Benguela), indicating that the locally forced response to the land‐sea breeze is a key driver of diapycnal mixing over the event. Alignment of the subinertial Ekman transport with the surface inertial oscillation produces shear spikes at the diurnal‐inertial frequency; however their impact on mixing is secondary when compared with the diurnal‐inertial resonance phenomenon. The amplitude of the diurnal anticyclonic rotary component of the wind stress represents a good diagnostic for the prediction of diapycnal mixing due to diurnal‐inertial resonance. The local enhancement of this quantity over St Helena Bay provides strong evidence for the importance of the land‐sea breeze in contributing to primary production in this region through nutrient enrichment of the surface layer.

show abstract

Section: Discussionmentioning

confidence: 99%

Enhanced Vertical Mixing in Coastal Upwelling Systems Driven by Diurnal‐Inertial Resonance: Numerical Experiments

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Such a boost of bottom remineralization can account for 40%-70% of the total input of inorganic nutrients by upwelled waters (Alonso-Pérez & Castro, 2014). This entry of regenerated nutrients to the water column due to downwelling-induced extreme bed shear stresses was also suggested by Kämpf (2019) as an important factor in the regenerated production levels on the North Carolina Shelf.…”

Section: Hydrodynamic and Biogeochemical Implications Of Asymmetric W...mentioning

confidence: 93%

Wave Regime and Wave‐Current Coupling in an Upwelling–Driven Bay: Seasonal and Inter‐Annual Variability

et al. 2021

View full text Add to dashboard Cite

Data from an acoustic Doppler current profiler (ADCP), a wave‐gauge, a met‐ocean buoy and model results provide new insights into the wave regime in a partially sheltered upwelling‐driven bay, the Ría de Vigo (NW Iberia), and the adjacent continental shelf from June 2013 to August 2014. Swell on the NW‐Iberian shelf comes mainly from NW directions, while wind sea comes from the NW under upwelling conditions, and from the SW under downwelling conditions. As the ria is protected from the NW and exposed to the SW, swell is almost always attenuated when entering the bay, and wave height inside the ria depends mostly on shelf wind sea variability. During the upwelling season, swell and wind sea barely enter the ria and wave heights inside the ria are small (0.21 m). During the downwelling season, shelf wind sea directly enters the ria, contributing more to the total wave height which achieves its maximum values (0.46 m). There is a cumulative action of wave and currents (wave current coupling, WCC) that is stronger during the downwelling season. The WCC entails an increase in the seabed energy which could reinforce bottom remineralization. The inter‐annual variability (2009–2016) of winter wave height and WCC in the ria is associated with the combined role played by the North Atlantic Oscillation (NAO) and West Europe Pressure Anomaly (WEPA) indices. The highest waves and strongest WCC occur during the coincidence of negative NAO and positive WEPA phases and can have potentially relevant repercussions on the ecosystem services of the ria.

show abstract

On the retroflection of upwelling jets near coastal bends

Kämpf

2024

Continental Shelf Research

View full text Add to dashboard Cite

Extreme bed shear stress during coastal downwelling

Cited by 5 publications

References 43 publications

Enhanced Vertical Mixing in Coastal Upwelling Systems Driven by Diurnal‐Inertial Resonance: Numerical Experiments

Enhanced Vertical Mixing in Coastal Upwelling Systems Driven by Diurnal‐Inertial Resonance: Numerical Experiments

Wave Regime and Wave‐Current Coupling in an Upwelling–Driven Bay: Seasonal and Inter‐Annual Variability

On the retroflection of upwelling jets near coastal bends

Contact Info

Product

Resources

About