Near-bottom suspended sediment variability caused by storms and near-inertial internal waves on the Ebro mid continental shelf (NW Mediterranean)

Strong typhoon winds enhance turbulent mixing, which induces sediment to resuspend and to promote chlorophyll-a (Chl-a) blooms in the continental shelf areas. In this study, we find limited Chl-a responses to three late autumn typhoons (typhoon Nesat, Mujigae and Khanun) in the northwestern South China Sea (NWSCS) using satellite observations. In climatology, the Chl-a and total suspended sediment (TSS) concentrations are high all year round with higher value in autumn in the offshore area of the NWSCS. After the typhoon passage, the Chl-a concentration increases slightly (23%), while even TSS enhances by 280% on the wide continental shelf of the NWSCS. However, in the southern area, located approximately 100 km from the typhoon tracks, both TSS and Chl-a concentrations increase 160% and 150% after typhoon passage, respectively. In the deeper area, the increased TSS concentration is responsible for the considerable increase of the Chl-a. An empirical analysis is applied to the data, which reveals the TSS and Chl-a processes during typhoon events. The results of this study suggest a different mechanism for Chl-a concentration increase and thus contribute toward further evaluation of typhoon-induced biological responses.

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Internal Waves over the Continental Shelf of the Heracles Peninsula: Modeling and Observation

Springer Proceedings in Earth and Environmental Sciences - Physical and Mathematical Modeling of Earth and Environment Processes (2018) ◽

10.1007/978-3-030-11533-3_9 ◽

2019 ◽

pp. 83-92

Author(s):

Vitalii Ivanov ◽

T. Ya. Shul’ga ◽

Andrei Bagaev ◽

Tatiana Plastun ◽

Alesia Medvedeva ◽

...

Keyword(s):

Continental Shelf ◽

Internal Waves

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Energy transformations and dissipation of nonlinear internal waves over New Jersey's continental shelf

Nonlinear Processes in Geophysics ◽

10.5194/npg-17-345-2010 ◽

2010 ◽

Vol 17 (4) ◽

pp. 345-360 ◽

Cited By ~ 41

Author(s):

E. L. Shroyer ◽

J. N. Moum ◽

J. D. Nash

Keyword(s):

Continental Shelf ◽

Internal Waves ◽

Turbulent Mixing ◽

Internal Tide ◽

Flux Divergence ◽

Wave Interactions ◽

Nonlinear Internal Waves ◽

Dissipative Loss ◽

Peak Energy

Abstract. The energetics of large amplitude, high-frequency nonlinear internal waves (NLIWs) observed over the New Jersey continental shelf are summarized from ship and mooring data acquired in August 2006. NLIW energy was typically on the order of 105 Jm−1, and the wave dissipative loss was near 50 W m−1. However, wave energies (dissipations) were ~10 (~2) times greater than these values during a particular week-long period. In general, the leading waves in a packet grew in energy across the outer shelf, reached peak values near 40 km inshore of the shelf break, and then lost energy to turbulent mixing. Wave growth was attributed to the bore-like nature of the internal tide, as wave groups that exhibited larger long-term (lasting for a few hours) displacements of the pycnocline offshore typically had greater energy inshore. For ship-observed NLIWs, the average dissipative loss over the region of decay scaled with the peak energy in waves; extending this scaling to mooring data produces estimates of NLIW dissipative loss consistent with those made using the flux divergence of wave energy. The decay time scale of the NLIWs was approximately 12 h corresponding to a length scale of 35 km (O(100) wavelengths). Imposed on these larger scale energetic trends, were short, rapid exchanges associated with wave interactions and shoaling on a localized topographic rise. Both of these events resulted in the onset of shear instabilities and large energy loss to turbulent mixing.

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Suspended Sediment Variability at the Solimões and Negro Confluence between May 2013 and February 2014

Geosciences ◽

10.3390/geosciences8070265 ◽

2018 ◽

Vol 8 (7) ◽

pp. 265 ◽

Cited By ~ 1

Author(s):

Thiago Marinho ◽

Naziano Filizola ◽

Jean-Michel Martinez ◽

Elisa Armijos ◽

André Nascimento

Keyword(s):

Suspended Sediment ◽

Satellite Images ◽

Suspended Sediments ◽

Left Bank ◽

Sediment Samples ◽

Negro River ◽

The World ◽

The Right ◽

Sediment Variability ◽

Solimões River

This study focuses on the confluence of two major rivers of the world, the Solimões River (white waters) and Negro River (black waters). Surface suspended sediment samples (SSC) and spectroradiometer taken along transverse profiles at 500 m intervals over a distance of 10 km, as well as satellite images (MODIS) during the hydrological year, were used to follow suspended sediment variability. In January and February, the confluence is dominated by white waters from the Solimões River in the two banks, and in June and July in the right bank by black waters from the Negro River and in the left bank by clear waters from the Solimões River. We found that indirect tools, such as reflectance obtained by spectrometer or MODIS images, can be used to determine surface suspended sediments in a contrasting zone.

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