scholarly journals Burial, remineralization and utilization of organic matter at the seafloor under a strong western boundary current. Annual progress report, 1 May 1993--30 April 1994

1993 ◽  
Author(s):  
R.A. Jahnke
Keyword(s):  
Organic Matter ◽  
Progress Report ◽  
Western Boundary Current ◽  
Western Boundary ◽  
Boundary Current ◽  
Annual Progress Report

scholarly journals Inorganic and organic geochemical fingerprinting of sediment sources and ocean circulation on a complex continental margin (São Paulo Bight, Brazil)

Ocean Science ◽  
2017 ◽  
Vol 13 (2) ◽  
pp. 209-222 ◽  
Author(s):  
Michel Michaelovitch de Mahiques ◽  
Till Jens Jörg Hanebuth ◽  
Renata Hanae Nagai ◽  
Marcia Caruso Bícego ◽  
Rubens Cesar Lopes Figueira ◽  
...  
Keyword(s):  
Organic Matter ◽  
Molecular Markers ◽  
Ocean Circulation ◽  
Western Boundary Current ◽  
Western Boundary ◽  
Boundary Current ◽  
Geochemical Fingerprinting ◽  
Brazil Current ◽  
Shelf Sediments ◽  
Upper Slope

Abstract. In this study, we use inorganic (metal) and organic (bulk and molecular) markers in sediment samples of the south-eastern Brazilian margin to investigate the response of geochemical fingerprints to the complex hydrodynamic processes present in the area. Results indicate the potential of export of terrigenous siliciclastic and organic constituents to the upper slope, even in an area with limited fluvial supply.Metal contents and especially the ln(Ti ∕ Al) and ln(Fe ∕ K) ratios make it possible to recognise the extension of shelf sediments toward the upper slope. Potassium, here expressed as ln(K ∕ Sc) and ln(K ∕ Al) ratios used as proxies of illite–kaolinite variations, proved to be an important parameter, especially because it allowed us to decipher the imprint of the northward flow of the Intermediate Western Boundary Current (IWBC) in comparison to the southward flows of the Brazil Current (BC) and Deep Western Boundary Current (DWBC). Using organic matter analyses, we were able to evaluate the extent of terrestrial contributions to the outer shelf and slope, even without the presence of significant fluvial input. In addition, molecular markers signify a slight increase in the input of C4-derived plants to the slope sediments, transported from distant areas by the main alongshore boundary currents, indicating that the terrestrial fraction of the organic matter deposited on the slope has a distinct origin when compared to shelf sediments.

scholarly journals Inorganic and organic geochemical fingerprinting of sediment sources and ocean circulation on a complex continental margin (São Paulo Bight, Brazil)

2016 ◽  
Author(s):  
Michel Michaelovitch de Mahiques ◽  
Till Jens Jörg Hanebuth ◽  
Renata Hanae Nagai ◽  
Marcia Caruso Bícego ◽  
Rubens Cesar Lopes Figueira ◽  
...  
Keyword(s):  
Organic Matter ◽  
Molecular Markers ◽  
Ocean Circulation ◽  
Western Boundary Current ◽  
Western Boundary ◽  
Boundary Current ◽  
Geochemical Fingerprinting ◽  
Brazil Current ◽  
Shelf Sediments ◽  
Upper Slope

Abstract. In this study, we use inorganic (metals) and organic (bulk and molecular) markers in sediment samples of the southeastern Brazilian margin to investigate the response of geochemical fingerprints to the complex hydrodynamic processes present in the area. Results indicate the potential of export of terrigenous siliciclastic and organic constituents to the upper slope, even in an area with limited fluvial supply. Metal contents and especially the ln(Ti/Al) and ln(Fe/K) ratios make it possible to recognize the extension of shelf sediments toward the upper slope. Potassium, here expressed as ln(K/Sc) and ln(K/Al) ratios used as proxies of illite–kaolinite variations, proved to be an important parameter, especially because it allowed us to decipher the imprint of the northward flow of the Intermediate Western Boundary Current (IWBC) in comparison to the southward flows of the Brazil Current (BC) and Deep Western Boundary Current (DWBC). Using organic matter analyses, we were able to evaluate the extent of terrestrial contributions to the outer shelf and slope, even without the presence of significant fluvial input. In addition, molecular markers signify a slight increase in the input of C4-derived plants to the slope sediments, transported from distant areas by the main alongshore boundary currents, indicating that the terrestrial fraction of the organic matter deposited on the slope has a distinct origin when compared to shelf sediments.

scholarly journals Frequency-Domain Analysis of the Energy Budget in an Idealized Coupled Ocean–Atmosphere Model

2020 ◽  
Vol 33 (2) ◽  
pp. 707-726 ◽  
Author(s):  
Paige E. Martin ◽  
Brian K. Arbic ◽  
Andrew McC. Hogg ◽  
Andrew E. Kiss ◽  
James R. Munroe ◽  
...  
Keyword(s):  
Frequency Domain ◽  
Time Scales ◽  
Energy Budget ◽  
Western Boundary Current ◽  
Spectral Energy ◽  
Western Boundary ◽  
Intrinsic Variability ◽  
Boundary Current ◽  
Ocean Atmosphere ◽  
Atmosphere Model

AbstractClimate variability is investigated by identifying the energy sources and sinks in an idealized, coupled, ocean–atmosphere model, tuned to mimic the North Atlantic region. The spectral energy budget is calculated in the frequency domain to determine the processes that either deposit energy into or extract energy from each fluid, over time scales from one day up to 100 years. Nonlinear advection of kinetic energy is found to be the dominant source of low-frequency variability in both the ocean and the atmosphere, albeit in differing layers in each fluid. To understand the spatial patterns of the spectral energy budget, spatial maps of certain terms in the spectral energy budget are plotted, averaged over various frequency bands. These maps reveal three dynamically distinct regions: along the western boundary, the western boundary current separation, and the remainder of the domain. The western boundary current separation is found to be a preferred region to energize oceanic variability across a broad range of time scales (from monthly to decadal), while the western boundary itself acts as the dominant sink of energy in the domain at time scales longer than 50 days. This study paves the way for future work, using the same spectral methods, to address the question of forced versus intrinsic variability in a coupled climate system.

scholarly journals Midlatitude–Equatorial Dynamics of a Grounded Deep Western Boundary Current. Part I: Midlatitude Flow and the Transition to the Equatorial Region

2015 ◽  
Vol 45 (10) ◽  
pp. 2457-2469 ◽  
Author(s):  
Gordon E. Swaters
Keyword(s):  
Bottom Topography ◽  
Zonal Flow ◽  
Ocean Basin ◽  
Equatorial Region ◽  
Western Boundary Current ◽  
Western Boundary ◽  
Boundary Current ◽  
Qualitative Properties ◽  
Deep Western Boundary Current ◽  
The Tropics

AbstractA comprehensive theoretical study of the nonlinear hemispheric-scale midlatitude and cross-equatorial steady-state dynamics of a grounded deep western boundary current is given. The domain considered is an idealized differentially rotating, meridionally aligned basin with zonally varying parabolic bottom topography so that the model ocean shallows on both the western and eastern sides of the basin. Away from the equator, the flow is governed by nonlinear planetary geostrophic dynamics on sloping topography in which the potential vorticity equation can be explicitly solved. As the flow enters the equatorial region, it speeds up and becomes increasingly nonlinear and passes through two distinguished inertial layers referred to as the “intermediate” and “inner” inertial equatorial boundary layers, respectively. The flow in the intermediate equatorial region is shown to accelerate and turn eastward, forming a narrow equatorial jet. The qualitative properties of the solution presented are consistent with the known dynamical characteristics of the deep western boundary currents as they flow from the midlatitudes into the tropics. The predominately zonal flow across the ocean basin in the inner equatorial region (and its exit from the equatorial region) is determined in Part II of this study.

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