Dispersion Experiments in U.K. Coastal Waters

Riddle, A.M.; Lewis, R.E.

doi:10.1006/ecss.2000.0661

Cited by 33 publications

(10 citation statements)

References 5 publications

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“…The K Z values calculated in this study (1.0-3.3 cm 2 s −1 ) fall within the lower end of the range of values (1-100 cm 2 s −1 ) obtained during an extensive dye tracing experiment in coastal and estuarine waters around the UK (Riddle and Lewis, 2000). This is not surprising given the relatively quiescent nature of the deep waters of Bedford Basin.…”

Section: K Z Measurementsmentioning

confidence: 56%

Sediment-water column fluxes of carbon, oxygen and nutrients in Bedford Basin, Nova Scotia, inferred from <sup>224</sup>Ra measurements

et al. 2013

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Abstract. Exchanges between sediment pore waters and the overlying water column play a significant role in the chemical budgets of many important chemical constituents. Direct quantification of such benthic fluxes requires explicit knowledge of the sediment properties and biogeochemistry. Alternatively, changes in water-column properties near the sediment-water interface can be exploited to gain insight into the sediment biogeochemistry and benthic fluxes. Here, we apply a 1-D diffusive mixing model to near-bottom watercolumn profiles of 224 Ra activity in order to yield vertical eddy diffusivities (K Z ), based upon which we assess the diffusive exchange of dissolved inorganic carbon (DIC), nutrients and oxygen (O 2 ), across the sediment-water interface in a coastal inlet, Bedford Basin, Nova Scotia, Canada. Numerical model results are consistent with the assumptions regarding a constant, single benthic source of 224 Ra, the lack of mixing by advective processes, and a predominantly benthic source and sink of DIC and O 2 , respectively, with minimal water-column respiration in the deep waters of Bedford Basin. Near-bottom observations of DIC, O 2 and nutrients provide flux ratios similar to Redfield values, suggesting that benthic respiration of primarily marine organic matter is the dominant driver. Furthermore, a relative deficit of nitrate in the observed flux ratios indicates that denitrification also plays a role in the oxidation of organic matter, although its occurrence was not strong enough to allow us to detect the corresponding A T fluxes out of the sediment. Finally, comparison with other carbon sources reveal the observed benthic DIC release as a significant contributor to the Bedford Basin carbon system.

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Section: K Z Measurementsmentioning

confidence: 56%

Sediment-water column fluxes of carbon, oxygen and nutrients in Bedford Basin, Nova Scotia, inferred from <sup>224</sup>Ra measurements

et al. 2013

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“…The applied sinusoidal variation of vertical velocity is an approximation to more complex turbulent processes which may cause accumulation of buoyant algae in near-surface windrows (Denman and Gargett 1983), stronger downward than upward velocities (Gargett and Wells 2007) or extended residence time in the middle of the Langmuir cell (Thorpe 2004). The revolution period was chosen according to Denman and Gargett (1983), Schubert andForster (1997), andRiddle andLewis (2000), who found periods of about 20 min for full overturn in typical Langmuir cells. Subsamples of 50 mL were taken from each bottle after thorough homogenization at sunrise of days 2-4.…”

Section: Experimental Approachmentioning

confidence: 99%

Influence of vertical mixing on light‐dependency of phytoplankton growth

Köhler

Wang

Guislain

et al. 2017

Limnology & Oceanography

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Phytoplankton growth depends not only on mean intensity but also on the dynamics of the light supply. In surface mixed layers, phytoplankton may rapidly move between strong light and almost darkness. The nonlinear light‐dependency of growth may differ between constant and fluctuating light because of the different frequency distribution of light and/or acclimation processes. The present study compares for the first time light‐dependency of photosynthesis and growth of phytoplankton communities in situ under defined mixing conditions and at fixed depths. Maximum growth rates per day were not significantly different, but the growth efficiency was much higher under constant light than under fluctuating light of sub‐saturating daily irradiance. Phytoplankton incubated under fluctuating light needed about three times higher mean daily irradiances to balance photosynthesis and losses than under constant light. The difference in growth efficiency was mostly caused by the different frequency distribution of underwater light, as was estimated by a photosynthesis model of sufficient temporal resolution. The present study indicates a considerable overestimation of phytoplankton growth at sub‐saturating light in well‐mixed water layers by the common growth measurements under constant light. This implies an underestimation of the compensation light intensities and respective overestimations of the critical mixing depths.

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“…BLACK and GORMAN (submitted) suggest that such wave-induced horizontal diffusivities are likely to range between 0.1 to 10 m 2 s Ϫ1 near the wave breakpoint, while MILL- ER and KOMAR (1979) measured averaged values of 6.35 ϫ 10 Ϫ5 m 2 s Ϫ1 in 16-18 m water depth. Indeed, the review of RIDDLE and LEWIS (2000) notes that horizontal diffusivity coefficients for water bodies (not sediment) in a variety of coastal and estuarine sites were found to range from 0.003 to 0.42 m 2 s Ϫ1 (median 0.05 m 2 s Ϫ1 ).…”

Section: Advection Diffusion and Dispersalmentioning

confidence: 98%

Detailed Observations of Littoral Transport Using Artificial Sediment Tracer, in a High-Energy, Rocky Reef and Iron Sand Environment

McComb¹,

Black²

2005

Journal of Coastal Research

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Dispersion Experiments in U.K. Coastal Waters

Cited by 33 publications

References 5 publications

Sediment-water column fluxes of carbon, oxygen and nutrients in Bedford Basin, Nova Scotia, inferred from <sup>224</sup>Ra measurements

Sediment-water column fluxes of carbon, oxygen and nutrients in Bedford Basin, Nova Scotia, inferred from <sup>224</sup>Ra measurements

Influence of vertical mixing on light‐dependency of phytoplankton growth

Detailed Observations of Littoral Transport Using Artificial Sediment Tracer, in a High-Energy, Rocky Reef and Iron Sand Environment

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Dispersion Experiments in U.K. Coastal Waters

Cited by 33 publications

References 5 publications

Sediment-water column fluxes of carbon, oxygen and nutrients in Bedford Basin, Nova Scotia, inferred from &lt;sup&gt;224&lt;/sup&gt;Ra measurements

Sediment-water column fluxes of carbon, oxygen and nutrients in Bedford Basin, Nova Scotia, inferred from &lt;sup&gt;224&lt;/sup&gt;Ra measurements

Influence of vertical mixing on light‐dependency of phytoplankton growth

Detailed Observations of Littoral Transport Using Artificial Sediment Tracer, in a High-Energy, Rocky Reef and Iron Sand Environment

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Product

Resources

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Sediment-water column fluxes of carbon, oxygen and nutrients in Bedford Basin, Nova Scotia, inferred from <sup>224</sup>Ra measurements

Sediment-water column fluxes of carbon, oxygen and nutrients in Bedford Basin, Nova Scotia, inferred from <sup>224</sup>Ra measurements