Inductive Telemetry on a Deep Ocean Surface Mooring.

1995 ◽  
Author(s):  
Daniel Frye ◽  
Alessandro Bocconcelli ◽  
Stephen Liberatore ◽  
Edward Hobart
Keyword(s):  
Deep Ocean ◽  
Ocean Surface

Test Set-Up for Irregular Vertical Hydraulic Transport in Deep Ocean Mining

2011 ◽  
Author(s):  
Arno M. Talmon ◽  
Cees van Rhee
Keyword(s):  
Fine Particles ◽  
Deep Ocean ◽  
Ocean Surface ◽  
Processing Plant ◽  
Coarse Particles ◽  
Hydraulic Transport ◽  
Test Set ◽  
Sea Floor ◽  
High Concentrations ◽  
Set Up

The mining of scarce minerals from the sea-floor at the depths of several kilometers and bringing them to a processing plant at the ocean surface requires new techniques. Seafloor Massive Sulphide (SMS) deposits are known to have an extremely rich mineral content, and are considered technically-economically-environmentally feasible to explore. Vertical hydraulic transport is the link between the sea-floor mining and the maritime vessel where the first processing stage will take place. Clogging of any part of the vertical transport system is an absolute disaster. Fine particles are conveyed faster than coarse particles. High concentrations of fines cannot bypass high concentrations of coarse particles, hence these particle fractions accumulate, potentially blocking the pipe. Fundamental research into yet unexplored physics is necessary. Besides numerical flow simulations, it is necessary to conducted experiments on the transport over large vertical distances. Such tests aim to investigate the dynamic development of density waves consisting of different particle diameters and clogging phenomenon thereof. Different particle size fractions have to be followed in real time as they overtake each other, and change their shape, merge and segregate. It is however impossible to back-scale the prototype riser to a one-pass laboratory test set-up, but the process can be simulated by repeated flow through an asymmetric vertical pipe loop, where slurry flow in the upward leg represent vertical hoist conditions and the slurry is returned quickly via the downward leg. The particle accumulation process is allowed to take place in the upward leg whereas in the downward leg the restoring process is nearly neutralized. The development of accumulations in time (= distance traveled to the ocean surface) can be followed upon multiple passes of the solids batches through the upward leg. The novelty of the described testing method is that the essentials of fundamental processes occurring in long vertical stretches are quantified in a specially designed laboratory setup. Via subsequent implementation of the results in a numerical flow simulation, reliable transport scenarios can be delineated.

scholarly journals Further Application of Bomb 14C as a Tracer in the Atmosphere and Ocean

Radiocarbon ◽  
1996 ◽  
Vol 38 (3) ◽  
pp. 389-406 ◽  
Author(s):  
Reidar Nydal ◽  
Jorunn S. Gislefoss
Keyword(s):  
Atlantic Ocean ◽  
Deep Ocean ◽  
Ocean Surface ◽  
Conventional Technique ◽  
Ventilation Rate ◽  
Norwegian Sea ◽  
University Of Arizona ◽  
Beta Counting ◽  
Nuclear Tests ◽  
The University

Bomb 14C from nuclear tests in the atmosphere has proved to be a particularly useful tool in the study of the carbon cycle. We provide here a ca. 30-yr time series of 14C concentrations in the atmosphere between 28°N and 71°N and in the ocean surface between 45°S and 45°N. More recently (since 1990), a north-south profile also has been obtained for 14C in the surface waters of the Atlantic Ocean. The measurements were performed using the conventional technique of beta counting or large samples (4 to 5 liter CO2) in CO2 proportional counters. These data show that the 14C concentration in the atmosphere is leveling off with a time constant of 0.055 yr-1, and is now approaching that of the ocean surface at lower latitudes.Additional tracer studies have been concerned especially with the penetration of bomb 14C into the deep ocean. The Norwegian and Greenland seas are of interest as a sink for atmospheric CO2 and also a source of water for the deep Atlantic Ocean. During the last five years, several 14C depth profiles have been measured from the Fram Strait (79°N) to south of Iceland (62°N), using the AMS technique available at the University of Arizona AMS Facility. We considered it important to repeat and compare a few of the profiles with those produced by the GEOSECS expedition in 1972 and the TTO expedition in 1981. The profiles show that water descending to the deep Atlantic Ocean is originating mainly from intermediate and surface depths in the Nordic Seas. However, the ventilation rate of the Norwegian Sea deepwater is too slow to be an important component in the transfer of water over the Greenland-Scotland Ridge.

scholarly journals Water isotope variations in the global ocean model MPI-OM

2012 ◽  
Vol 5 (3) ◽  
pp. 809-818 ◽  
Author(s):  
X. Xu ◽  
M. Werner ◽  
M. Butzin ◽  
G. Lohmann
Keyword(s):  
Surface Waters ◽  
General Circulation ◽  
Large Scale ◽  
Circulation Model ◽  
Deep Ocean ◽  
Ocean Surface ◽  
Ocean Model ◽  
Global Ocean ◽  
Stable Water Isotopes ◽  
Tropical Regions

Abstract. The stable water isotopes H218O and HDO are incorporated as passive tracers into the oceanic general circulation model MPI-OM, and a control simulation under present-day climate conditions is analyzed in detail. Both δ18O and δD distributions at the ocean surface and deep ocean are generally consistent with available observations on the large scale. The modelled δD-δ 18O relations in surface waters slightly deviates from the slope of the global meteoric water line in most basins, and a much steeper slope is detected in Arctic Oceans. The simulated deuterium excess of ocean surface waters shows small variations between 80° S and 55° N, and a strong decrease north of 55° N. The model is also able to capture the quasi-linear relationship between δ18O and salinity S, as well as δD and S, as seen in observational data. Both in the model results and observations, the surface δ−S relations show a steeper slope in extra-tropical regions than in tropical regions, which indicates relatively more addition of isotopically depleted water at high latitudes.

scholarly journals Persistent Lagrangian Transport Patterns in the Northwestern Gulf of Mexico

2019 ◽  
Vol 49 (2) ◽  
pp. 353-367 ◽  
Author(s):  
Matt K. Gough ◽  
Francisco J. Beron-Vera ◽  
María J. Olascoaga ◽  
Julio Sheinbaum ◽  
Julien Jouanno ◽  
...  
Keyword(s):  
Gulf Of Mexico ◽  
Coherent Structures ◽  
Oil Spills ◽  
Deep Ocean ◽  
Surface Current ◽  
Ocean Surface ◽  
Shelf Break ◽  
Lagrangian Transport ◽  
Free Running ◽  
Transport Patterns

AbstractPersistent Lagrangian transport patterns at the ocean surface are revealed from climatological Lagrangian coherent structures (cLCSs) computed from daily climatological surface current velocities in the northwestern Gulf of Mexico (NWGoM). The climatological currents are computed from daily velocities produced by an 18-yr-long free-running submesoscale-permitting Nucleus for European Modelling of the Ocean (NEMO) simulation of the Gulf of Mexico. Despite the intense submesoscale variability produced by the model along the shelf break, which is found to be consistent with observations and previous studies, a persistent mesoscale attracting barrier between the NWGoM shelf and the deep ocean is effectively identified by a hook-like pattern associated with persistent strongly attracting cLCSs. Simulated tracer and satellite-tracked drifters originating over the shelf tend to be trapped there by the hook-like pattern as they spread cyclonically. Tracers and drifters originating beyond the shelf tend to be initially attracted to the hook-like pattern as they spread anticyclonically and eventually over the deep ocean. The findings have important implications for the mitigation of contaminant accidents such as oil spills.

Observation of ocean surface scattering in the deep ocean using a towed array

2011 ◽  
Vol 130 (4) ◽  
pp. 2348-2348
Author(s):  
Stephen D. Lynch ◽  
Gerald L. D'Spain ◽  
Kevin D. Heaney ◽  
Arthur B. Baggeroer ◽  
Peter Worcester ◽  
...  
Keyword(s):  
Deep Ocean ◽  
Ocean Surface ◽  
Surface Scattering ◽  
Towed Array

scholarly journals Water isotope variations in the global ocean model MPI-OM

2012 ◽  
Vol 5 (1) ◽  
pp. 277-307
Author(s):  
X. Xu ◽  
M. Werner ◽  
M. Butzin ◽  
G. Lohmann
Keyword(s):  
Surface Waters ◽  
General Circulation ◽  
Large Scale ◽  
Circulation Model ◽  
Deep Ocean ◽  
Ocean Surface ◽  
Ocean Model ◽  
Global Ocean ◽  
Stable Water Isotopes ◽  
Tropical Regions

Abstract. The stable water isotopes H218O and HDO are incorporated as passive tracers into the oceanic general circulation model MPI-OM, and a control simulation under present-day climate conditions is analyzed in detail. Both δ18O and δD distributions at the ocean surface and deep ocean are generally consistent with available observations on the large scale. The modelled δD-δ18O relations in surface waters slightly deviates from the slope of the global meteoric water line in most basins, and a much steeper slope is detected in Arctic Oceans. The simulated deuterium excess of ocean surface waters shows small variations between 80° S and 55° N, and a strong decrease north of 55° N. The model is also able to capture the quasi-linear relationship between δ18O and salinity S, as well as δD and S, as seen in observational data. Both in the model results and observations, the surface δ–S relations show a steeper slope in extra-tropical regions than in tropical regions, which indicates relatively more addition of isotopically depleted water at high latitudes.

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