Sea level budget over 2005–2013: missing contributions and data errors
Ocean Sci., 11, 789-802, doi:10.5194/os-11-789-2015, 2015
Estimation of upward radiances and reflectances at the surface of the sea from above-surface measurements
Summary: A method which determines the radiance reflectance at the surface as well as the water-leaving and reflected radiances solely from the measurements of upward nadir radiance and downward irradiance in air is presented. A comparison between this method and in situ measurements shows that the average relative deviations between their results are less than or equal to 15% for the reflected radiance, at the studied wavelengths.
Ocean Sci., 11, 779-788, doi:10.5194/os-11-779-2015, 2015
Spatio-temporal variability of micro-, nano- and pico-phytoplankton in the Mediterranean Sea from satellite ocean colour data of SeaWiFS
Summary: We describe the seasonal and year-to-year variability of the spatial distribution of the phytoplankton size classes (PSCs) in the Mediterranean Sea using the time series of Sea-viewing Wide Field-of-view Sensor (SeaWiFS) observations (1998 to 2010). We used a chlorophyll-a-based model to estimate the phytoplankton composition. Our results, based on ocean colour data, confirm the seasonal and inter-annual pattern of the phytoplankton community observed from in situ data and in previous studies.
Ocean Sci., 11, 759-778, doi:10.5194/os-11-759-2015, 2015
Transport of volume, heat, and salt towards the Arctic in the Faroe Current 1993–2013
Summary: The Faroe Current is the main ocean current transporting warm Atlantic water into the Arctic region and an important transporter of heat towards the Arctic. This study documents observed transport variations over two decades, from 1993 to 2013. It shows that the volume transport of Atlantic water in this current increased by 9% over the period, whereas the heat transport increased by 18%. This increase will have contributed to the observed warming and sea ice decline in the Arctic.
Ocean Sci., 11, 743-757, doi:10.5194/os-11-743-2015, 2015
Global representation of tropical cyclone-induced short-term ocean thermal changes using Argo data
Summary: 1. Argo floats were used to examine tropical cyclone (TC) induced ocean thermal changes on the global scale by comparing temperature profiles before and after TC passage. 2. Global average of the vertical structure of the average ocean thermal response for two different categories: tropical storms/depressions (TS/TD) and hurricanes were presented. 3. Significant differences between weak storm (TS/TD) and strong storm (hurricane) were found.
Ocean Sci., 11, 719-741, doi:10.5194/os-11-719-2015, 2015
Perspectives of transient tracer applications and limiting cases
Summary: We use a suite of transient tracer measurements from a Southern Ocean sector southeast of Africa collected from 1998 and 2012 to quantify ventilation and change in ventilation. We found that the ventilation can be constrained by an inverse Gaussian transit time distribution north of the Subantarctic Front. We do not find any significant changes in upper ocean ventilation during this time period.
Ocean Sci., 11, 699-718, doi:10.5194/os-11-699-2015, 2015
Technical Note: Remote sensing of sea surface salinity using the propagation of low-frequency navigation signals
Summary: This paper introduces a potential method for determining the salinity of the ocean surface from long-wave radio signals used for navigation (and potentially other AM radio transmissions). Here we seek to retrieve ocean surface salinity averaged along a path across the North Sea between Denmark and the UK and compare our results with satellite-derived salinity.
Ocean Sci., 11, 695-698, doi:10.5194/os-11-695-2015, 2015
Mesoscale variability in the Arabian Sea from HYCOM model results and observations: impact on the Persian Gulf Water path
Summary: The Arabian Sea and Sea of Oman have a complex oceanic circulation, strongly influenced by the monsoons. The aim of this article is to describe the mesoscale processes that dominate the region, large eddies with a strong vertical influence, with their seasonal and interannual variability, from their formations, evolutions and interactions. Thus, an emphasis is placed on the highly saline Persian Gulf outflow in the Sea of Oman, and its interaction with the mesoscale circulation.
Ocean Sci., 11, 667-693, doi:10.5194/os-11-667-2015, 2015
Impact of currents on surface flux computations and their feedback on dynamics at regional scales
Summary: The paper studies the impact of the use of relative winds (i.e., winds minus ocean currents) to compute heat and momentum fluxes at sea surface. This was done in an area interested by mesoscale eddies and a local boundary current. Impact is relevant both for heat and momentum fluxes. Major differences can be observed in areas with large mesoscale activity. Results suggest that surface currents component in fluxes computation should not be neglected even at such scales and latitudes.
Ocean Sci., 11, 657-666, doi:10.5194/os-11-657-2015, 2015
Simulation of tsunami generation, propagation and coastal inundation in the Eastern Mediterranean
Summary: An advanced tsunami generation, propagation and coastal inundation model is applied to simulate representative earthquake-induced tsunami scenarios in the Eastern Mediterranean. Two areas of interest were selected after evaluating tsunamigenic zones and possible sources in the region: one at the SE of Crete (Greece) and one at the E of Sicily (Italy). Results are indicative of the model’s capabilities, as well of how areas in the Eastern Mediterranean would be affected by eventual larger events.
Ocean Sci., 11, 643-655, doi:10.5194/os-11-643-2015, 2015
Eddy surface properties and propagation at Southern Hemisphere western boundary current systems
Summary: Oceanic eddies are closed circulation features that transport water between regions, taking part in the ocean's heat and salt balance. We perform a comparative eddy census in the East Australian, Agulhas and Brazil currents. We find that eddy propagation in all systems is steered by the local mean flow and bathymetry. Also, eddies present a geographic segregation according to size. Investigating eddy propagation helps us to better understand their effect in local mixing.
Ocean Sci., 11, 629-641, doi:10.5194/os-11-629-2015, 2015
Sea level trend and variability around Peninsular Malaysia
Ocean Sci., 11, 617-628, doi:10.5194/os-11-617-2015, 2015
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