Accelerated sea level rise and Florida Current transport
Summary: Changes in mass transport of the Florida Current induce significant coastal sea level changes along the Florida Straits and middle Atlantic coast of North America. Analysis of Florida Current transport data finds a decrease in mean transport over the last decade. This decrease coincides with a decrease in AMOC and acceleration of coastal sea levels along the Florida Straits.
Ocean Sci., 11, 607-615, doi:10.5194/os-11-607-2015, 2015
Exploring the isopycnal mixing and helium–heat paradoxes in a suite of Earth system models
Summary: Many ocean circulation models use representations of lateral mixing based on instability theories that predict weak mixing in the ocean interior, much lower than observed. We show that using more realistic mixing improves the distribution of mantle helium-3. It does not, however, resolve the paradox that models reproduce the relationship between mantle helium and radiocarbon with a flux of helium-3 lower than is consistent with the heat leaving the mantle.
Ocean Sci., 11, 591-605, doi:10.5194/os-11-591-2015, 2015
Constraining parameters in marine pelagic ecosystem models – is it actually feasible with typical observations of standing stocks?
Summary: Marine biogeochemical ocean models are embedded into earth system models - which are, to an increasing degree, applied to project the fate of our warming world. These biogeochemical models generally depend on poorly constrained model parameters. In this study we investigate the the demands on observations for an objective estimation of such parameters. A major result is that even modest noise (10%) inherent to observations can hinder the assignment of reasonable parameters.
Ocean Sci., 11, 573-590, doi:10.5194/os-11-573-2015, 2015
Reconstructing bottom water temperatures from measurements of temperature and thermal diffusivity in marine sediments
Summary: Temperature fields in marine sediments are controlled by the geothermal steady state heat flow and the bottom water temperature. Thus, the current sediments' temperature field stores the history of bottom water temperature variation. The aim of this work is the inverse modeling of the bottom water temperature variation in the last year from instantaneous measurements of the depth-dependent temperature and the thermal diffusivity.
Ocean Sci., 11, 559-571, doi:10.5194/os-11-559-2015, 2015
Investigation of suitable sites for wave energy converters around Sicily (Italy)
Summary: The paper describes the analysis of wave energy along the coast of Sicily (Italy). A third-generation model was adopted to reconstruct the wave data along the coast over a period of 14 years. The analysis of the wave energy allowed characterising the most energetic zones and to individuate eight hotspots suitable for the implementation of wave energy converter farms.
Ocean Sci., 11, 543-557, doi:10.5194/os-11-543-2015, 2015
The OceanFlux Greenhouse Gases methodology for deriving a sea surface climatology of CO2 fugacity in support of air–sea gas flux studies
Summary: We describe the OceanFlux Greenhouse Gases methodology for creating an ocean surface CO2 climatology. In situ measurements valid for instantaneous sea surface temperature (SST) were recomputed using a more consistent and averaged SST. The results were normalised to year 2010, averaged by month, and interpolated onto a global 1°×1° grid. The 12 monthly distributions of ocean surface CO2 (see supplement) can be used in air-sea gas flux calculations together with climatologies of other variables.
Ocean Sci., 11, 519-541, doi:10.5194/os-11-519-2015, 2015
Mean circulation in the coastal ocean off northeastern North America from a regional-scale ocean model
Ocean Sci., 11, 503-517, doi:10.5194/os-11-503-2015, 2015
Decadal variability and trends of the Benguela upwelling system as simulated in a high-resolution ocean simulation
Summary: The atmospheric drivers of the Benguela upwelling systems and its variability are statistically analysed with an ocean-only simulation over the last decades. Atmospheric upwelling-favourable conditions are southerly wind/wind stress, a strong subtropical anticyclone, and an ocean-land sea level pressure gradient as well as a negative ENSO and a positive AAO phase. No long-term trends of upwelling and of ocean-minus-land air pressure gradients, as supposed by Bakun, can be seen in our analysis.
Ocean Sci., 11, 483-502, doi:10.5194/os-11-483-2015, 2015
Dynamics of turbulent western-boundary currents at low latitude in a shallow-water model
Ocean Sci., 11, 471-481, doi:10.5194/os-11-471-2015, 2015
Circulation, eddies, oxygen, and nutrient changes in the eastern tropical South Pacific Ocean
Summary: Mean circulation in the eastern tropical South Pacific in 50-600m depth is modified by seasonal variability and eddies on the poleward side of the oxygen minimum zone(OMZ). Floats with parking depth at 400m show westward flow in the equatorial channel, sluggish flow in the northern part of the OMZ, and passage of eddies with oxygen anomalies. Net community production rates were estimated from a float. Oxygen decrease in 50-300m depth since 1976 is related to an increase in nitrate and phosphate.
Ocean Sci., 11, 455-470, doi:10.5194/os-11-455-2015, 2015
Water level oscillations in Monterey Bay and Harbor
Summary: Seiches in coastal bays can produce significant water level oscillations that impact maritime operations and introduce ecological stress. Monterey Bay, California, is found to have wave-driven short-period oscillations that can reinforce themselves, resulting in water level amplification. At longer periods the oscillations are not wave-driven and several potential forcing mechanisms are examined. A gyre offshore the bay is suggested as the driver, while other potential drivers are discounted.
Ocean Sci., 11, 439-453, doi:10.5194/os-11-439-2015, 2015
Assessment of an ensemble system that assimilates Jason-1/Envisat altimeter data in a probabilistic model of the North Atlantic ocean circulation
Summary: A realistic ocean circulation model is adapted to explicitly simulate model uncertainties and an ensemble data assimilation -stochastic perturbations, altimetric data and 4-D observation operator- is developed in order to control the Gulf Stream dynamic. The performance of the ensemble system is measured through probabilistic approach; the update then adjusts the bias and the dispersion of the ensemble (reliability) and reduces the uncertainty by 30% (resolution) for the SSH variable.
Ocean Sci., 11, 425-438, doi:10.5194/os-11-425-2015, 2015
Modelling survival and connectivity of Mnemiopsis leidyi in the south-western North Sea and Scheldt estuaries
Summary: The reproduction, survival, and transport of the comb jelly Mnemiopsis leidyi was studied with three models in the Scheldt estuaries and the southern North Sea. The results suggest that (a) the estuaries can retain an overwintering population and seed offshore populations; (b) M. leidyi can survive in the North Sea, and be transported between coastal inlets; and (c) M. leidyi cannot reproduce well in the North Sea, but this might change with global warming. The models need further improvement.
Ocean Sci., 11, 405-424, doi:10.5194/os-11-405-2015, 2015
Friction and mixing effects on potential vorticity for bottom current crossing a marine strait: an application to the Sicily Channel (central Mediterranean Sea)
Ocean Sci., 11, 391-403, doi:10.5194/os-11-391-2015, 2015
Retrieving the availability of light in the ocean utilising spectral signatures of vibrational Raman scattering in hyper-spectral satellite measurements
Ocean Sci., 11, 373-389, doi:10.5194/os-11-373-2015, 2015
Eddy characteristics in the South Indian Ocean as inferred from surface drifters
Summary: Eddies in the South Indian Ocean (SIO) were statistically investigated based on 2082 surface drifters, and 19252 eddies were identified with 60% anticyclonic eddies. Mesoscale and submesoscale eddies show different spatial distributions. Large eddies mainly appear in regions with large eddy kinetic energy. The submesoscale anticyclonic eddies are densely distributed in the subtropical basin in the central SIO. The number of mesoscale eddies shows statistically significant seasonal variability.
Ocean Sci., 11, 361-371, doi:10.5194/os-11-361-2015, 2015
Deep drivers of mesoscale circulation in the central Rockall Trough
Summary: The Rockall Trough feeds warm salty water to Polar regions and the European Shelf. Detailed observations from an underwater glider show that a) the meandering surface current field in the central trough is driven by deep eddies; b) chance circulations deflect the eastern slope current and warm the western side; c) and altimeter observations omit the mean flow in the narrow slope current. There are wider implications for satellite altimeter observations, ocean monitoring and ocean model results.
Ocean Sci., 11, 343-359, doi:10.5194/os-11-343-2015, 2015
Modelling of the anthropogenic tritium transient and its decay product helium-3 in the Mediterranean Sea using a high-resolution regional model
Summary: The anthropogenic tritium invasion, and its decay product helium-3, was simulated for the first time in the Mediterranean Sea, using a high-resolution regional model (NEMO-MED12). The simulation covers the entire tritium (3H) transient generated by the atmospheric nuclear weapons tests performed in the 1950s and early 1960s and run until 2011. The model correctly simulates the main features of the thermohaline circulation in the Mediterranean Sea, with a realistic time compared to observations.
Ocean Sci., 11, 323-342, doi:10.5194/os-11-323-2015, 2015
Technical Note: A fully automated purge and trap GC-MS system for quantification of volatile organic compound (VOC) fluxes between the ocean and atmosphere
Summary: The oceans are a key source of a number of atmospherically important volatile gases. The accurate and robust determination of trace gases in seawater is a significant analytical challenge. Here we describe a gas chromatograph mass spectrometer based purge and trap system that was developed for the fully automated analysis of dissolved very short-lived species (VSLS) in seawater sampled from a research ship.
Ocean Sci., 11, 313-321, doi:10.5194/os-11-313-2015, 2015
Correlation between subsurface high-salinity water in the northern South China Sea and the North Equatorial Current–Kuroshio circulation system from HYCOM simulations
Summary: Here, we investigated the seasonal variability of subsurface high-salinity water (SHSW) in the northern South China Sea (SCS) and its relationship with the North Equatorial Current-Kuroshio circulation system. Results give new insight into water exchange through the Luzon Strait (LS). The changes in western Pacific large-scale circulation modulate the water exchange in the LS, and thus influence the SHSW in the interior SCS basin.
Ocean Sci., 11, 305-312, doi:10.5194/os-11-305-2015, 2015