Temporal variability of near-bottom particle resuspension and dynamics at the Porcupine Abyssal Plain, Northeast Atlantic

Vangriesheim, Annick; Springer, Barbara; Crassous, Philippe

doi:10.1016/s0079-6611(01)00051-9

Cited by 34 publications

(29 citation statements)

References 50 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Unsteady flows caused by semi-diurnal tides, inertial oscillations, and low frequency synoptic-scale eddies also affect the formation of the BBL (Richards, 1990). Added to these, the availability of suspended near seafloor organic material will be influenced by seasonal and regional variation in the flux and composition of material from surface waters (Lampitt, 1985;Richardson et al, 1993;Lampitt et al, 2000;Vangriesheim et al, 2001). Thus the height and dynamics of the BBL are likely to be site and season dependent, with hydrodynamic heterogeneity increasing with increased topographic complexity.…”

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

Near seafloor bioluminescence, macrozooplankton and macroparticles at the Mid-Atlantic Ridge

Craig

Youngbluth

Jamieson

et al. 2015

Deep Sea Research Part I: Oceanographic Research Papers

View full text Add to dashboard Cite

Section: Discussionmentioning

confidence: 99%

“…Baldwin et al, 1998;Lampitt et al, 2000;Vangriesheim et al, 2001). This increased flux near the seafloor comprises organic material that is horizontally advected or re-suspended from the seabed, as well as upward fluxes of buoyant material (Smith et al, 1989).…”

Section: Introductionmentioning

confidence: 99%

Near seafloor bioluminescence, macrozooplankton and macroparticles at the Mid-Atlantic Ridge

Craig

Youngbluth

Jamieson

et al. 2015

Deep Sea Research Part I: Oceanographic Research Papers

View full text Add to dashboard Cite

“…Typically, the BNL has a thickness up to tens to hundreds of meters (e.g., Turnewitsch and Springer, 2001;Inthorn et al, 2006). The amount and spatial extension of these remobilizations depends not only on physical processes, but also on the megafauna composition, the type of the material deposited (e.g., Vangriesheim et al, 2001;Lampitt et al, 2001), or the abundance and activity of groundfish (Yahel et al, 2008).…”

Section: Combining Model Metricsmentioning

confidence: 99%

Swept under the carpet: organic matter burial decreases global ocean biogeochemical model sensitivity to remineralization length scale

Kriest

Oschlies

2013

Biogeosciences

View full text Add to dashboard Cite

Abstract. Although of substantial importance for marine tracer distributions and eventually global carbon, oxygen, and nitrogen fluxes, the interaction between sinking and remineralization of organic matter, benthic fluxes and burial is not always represented consistently in global biogeochemical models. We here aim to investigate the relationships between these processes with a suite of global biogeochemical models, each simulated over millennia, and compared against observed distributions of pelagic tracers and benthic and pelagic fluxes.We concentrate on the representation of sediment-water interactions in common numerical models, and investigate their potential impact on simulated global sediment-water fluxes and nutrient and oxygen distributions. We find that model configurations with benthic burial simulate global oxygen well over a wide range of possible sinking flux parameterizations, making the model more robust with regard to uncertainties about the remineralization length scale. On a global scale, burial mostly affects oxygen in the meso-to bathypelagic zone. While all model types show an almost identical fit to observed pelagic particle flux, and the same sensitivity to particle sinking speed, comparison to observational estimates of benthic fluxes reveals a more complex pattern, but definite interpretation is not straightforward because of heterogeneous data distribution and methodology. Still, evaluating model results against observed pelagic and benthic fluxes of organic matter can complement model assessments based on more traditional tracers such as nutrients or oxygen. Based on a combined metric of dissolved tracers and biogeochemical fluxes, we here identify two model descriptions of burial as suitable candidates for further experiments and eventual model refinements.

show abstract

“…(3) Further evidence for the modulating influence of tides on particle dynamics in near-seafloor waters of the deep sea comes from turbidity time series that showed that there are times and / or environmental settings where turbidity at O(0.1-1 mab) varies at a tidal frequency. This was observed in fluid-dynamically more vigorous Deep Western Boundary Currents (e.g., Pak, 1983;Gross et al, 1986) as well as on the fluiddynamically more quiescent eastern sides of ocean basins (Lampitt et al, 1985;Vangriesheim and Khripounoff, 1990;Auffret et al, 1994;Vangriesheim et al, 2001;Turnewitsch et al: unpublished data from the Cape Verde Rise). (4) Finally, the deduced range of time scales that are critical for the maintenance of BNLs has also been indirectly confirmed by the presence of radioactive disequilibria (radioactivity ratios < 1) between the highly particle-reactive and short-lived radioactive thorium-234 ( 234 Th) daughter nuclide (half life: 24.1 d) and the non-particle-reactive (chemically conservative) and extremely long-lived radioactive uranium-238 ( 238 U) parent nuclide (half life: 4.468 × 10 9 yr) in near-seafloor waters in a number of locations in the deep sea (Bacon and Rutgers van der Loeff, 1989;DeMaster et al, 1991;Turnewitsch and Springer, 2001;Turnewitsch et al, 2008;R.…”

Section: Introductionmentioning

confidence: 90%

“…However, output from the TPXO barotropic tidal model of Egbert and Erofeeva (2002) gives sufficiently robust information on the timing of semidiurnal and neap / spring tidal oscillations during the sediment-trap time series. Moreover, there is a comprehensive time-series dataset of current velocities for the study area that was acquired in 1996/97 and discussed by Vangriesheim et al (2001). The current meter (Aanderaa RCM8) was suspended above a benthic lander at a nominal height above the seafloor of 15 m at 48°56.06'N, 16°31.93'W (48.934°N, 16.532°W), recording vector-averaged hourly bins from 08:00 UTC on 30 July 1996 to 11:00 UTC on 22 October 1997.…”

Section: Physical-oceanographic Turbidity and Fluid-dynamic Informationmentioning

confidence: 99%

Can neap-spring tidal cycles modulate biogeochemical fluxes in the abyssal near-seafloor water column?

Turnewitsch

Dale

Lahajnar

et al. 2017

Progress in Oceanography

View full text Add to dashboard Cite

Please cite this article as: Turnewitsch, R., Dale, A., Lahajnar, N., Lampitt, R.S., Sakamoto, K., Can neap-spring tidal cycles modulate biogeochemical fluxes in the abyssal near-seafloor water column?, Progress in Oceanography (2017), doi: http://dx. AbstractBefore particulate matter that settles as 'primary flux' from the interior ocean is deposited into deep-sea sediments it has to traverse the benthic boundary layer (BBL) that is likely to cover almost all parts of the seafloor in the deep seas. Fluid dynamics in the BBL differ vastly from fluid dynamics in the overlying water column and, consequently, have the potential to lead to quantitative and compositional changes between primary and depositional fluxes.Despite this potential and the likely global relevance very little is known about mechanistic and quantitative aspects of the controlling processes. Here, results are presented for a sediment-trap time-series study that was conducted on the Porcupine Abyssal Plain in the abyssal Northeast Atlantic, with traps deployed at 2, 40 and 569 meters above bottom (mab).The two bottommost traps were situated within the BBL-affected part of the water column.The time series captured 3 neap and 4 spring tides and the arrival of fresh settling material originating from a surface-ocean bloom. In the trap-collected material, total particulate matter (TPM), particulate inorganic carbon (PIC), biogenic silica (BSi), particulate organic carbon (POC), particulate nitrogen (PN), total hydrolysable amino acids (AA), hexosamines (HA) and lithogenic material (LM) were determined. The biogeochemical results are presented within the context of time series of measured currents (at 15 mab) and turbidity (at 1 mab). The main outcome is evidence for an effect of neap / spring tidal oscillations on particulate-matter dynamics in BBL-affected waters in the deep sea. Based on the frequency-decomposed current measurements and numerical modelling of BBL fluid dynamics, it is concluded that the neap / spring tidal oscillations of particulate-matter dynamics are less likely due to temporally varying total free-stream current speeds and more likely due to temporally and vertically varying turbulence intensities that result from the temporally varying interplay of different rotational flow components (residual, tidal, near-inertial) within the BBL. Using information from previously published empirical and theoretical relations between fluid and biogeochemical dynamics at the scale of individual particle aggregates, a conceptual and semi-quantitative picture of a mechanism was derived that explains how the neap / spring 3 fluid-dynamic oscillations may translate through particle dynamics into neap / spring oscillations of biogeochemical aggregate decomposition (microbially driven organic-matter breakdown, biomineral dissolution). It is predicted that, during transitions from neap into spring tides, increased aggregation in near-seafloor waters and/ or reduced deposition of aggregates at the seafloor coincides with reduced biogeochemical partic...

show abstract

Temporal variability of near-bottom particle resuspension and dynamics at the Porcupine Abyssal Plain, Northeast Atlantic

Cited by 34 publications

References 50 publications

Near seafloor bioluminescence, macrozooplankton and macroparticles at the Mid-Atlantic Ridge

Near seafloor bioluminescence, macrozooplankton and macroparticles at the Mid-Atlantic Ridge

Swept under the carpet: organic matter burial decreases global ocean biogeochemical model sensitivity to remineralization length scale

Can neap-spring tidal cycles modulate biogeochemical fluxes in the abyssal near-seafloor water column?

Contact Info

Product

Resources

About