Investigation of model capability in capturing vertical hydrodynamic coastal processes: a case study in the North Adriatic Sea
Summary: First modeling work comparing SHYFEM and MITgcm performance in the North Adriatic Sea; the treatment of heat/mass fluxes at the surface affects the models skill to reproduce coastal processes; high resolution is needed close to the coast, while lower resolution in the offshore is adequate to capture the dense water event; correct river discharges and temperature are vital for the reproduction of estuarine dynamics; nonhydrostatic processes do not influence the dense water formation.
Ocean Sci. Discuss., 12, 1625-1668, doi:10.5194/osd-12-1625-2015, 2015
The Civitavecchia Coastal Environment Monitoring System (C-CEMS): a new tool to analyse the conflicts between coastal pressures and sensitivity areas
Summary: The Civitavecchia Coastal Environment Monitoring System (C-CEMS) has been developed by the Laboratory of Experimental Oceanology and Marine Ecology in order to analyse the conflicts between human pressures and ecosystem conservation. As examples the analysis of faecal bacteria dispersion for bathing water quality assessment and the evaluation of the effects of the dredged activities on Posidonia meadows are reported. Finally C-CEMS can be considered a new useful tool for coastal zone management.
Ocean Sci. Discuss., 12, 1595-1623, doi:10.5194/osd-12-1595-2015, 2015
On the feasibility of the use of wind SAR to downscale waves on shallow water
Summary: High resolution wave hindcast has been performed for northern Adriatic Sea using a hybrid methodology, combining a regional wave hindcast data base, wind reanalysis, satellite SAR wind fields and data mining techniques. Comparison with in situ instrumental data indicate the good quality of the downscaled waves, moreover a good correlation was found on the downscaled waves forced with different wind fields. Results demonstrates how SAR wind fields can be successfully up-taken in wave downscaling.
Ocean Sci. Discuss., 12, 1567-1593, doi:10.5194/osd-12-1567-2015, 2015
Bio-optical characterization and light availability parametrization in two glacial melt water influenced estuary systems (West-Greenland)
Summary: In 2012 measurements were conducted in two adjacent estuary systems on Greenland’s west coast which are strongly influenced by glacial melt water. Results described in this study show the relevance of inorganic SPM and Chl a alike, while colored dissolved organic matter is less prominent. Light availability was recorded throughout the cruise and an effective two component (Chl a and inorganic SPM) model for PAR is developed to fill observational gaps from insufficient light conditions.
Ocean Sci. Discuss., 12, 1537-1566, doi:10.5194/osd-12-1537-2015, 2015
Accuracy of the mean sea level continuous record with future altimetric missions: Jason-3 vs. Sentinel-3a
Summary: The reference Mean Sea Level record, essential for the understanding of climate evolution, is derived from the altimetric measurements of the TOPEX/Poseidon mission, followed by Jason-1 and later Jason-2 on the same orbit. Soon, Jason-3 will be launched on the same historical orbit, followed by Sentinel-3a on a new one. This paper shows linking missions with the same orbit allows to meet climate users requirements regarding the MSL trend while using Sentinel-3a would increase the uncertainty.
Ocean Sci. Discuss., 12, 1511-1536, doi:10.5194/osd-12-1511-2015, 2015
Biased thermohaline exchanges with the arctic across the Iceland-Faroe Ridge in ocean climate models
Ocean Sci. Discuss., 12, 1471-1510, doi:10.5194/osd-12-1471-2015, 2015
Mapping turbulent diffusivity associated with oceanic internal lee waves offshore Costa Rica
Summary: Lee waves play a significant role in ocean mixing, but are difficult to study with traditional casts, moorings, and tows due to their stationary nature and limited spatial extent. We develop a new method to estimate turbulent diffusivity from seismic data and find elevated levels of turbulence associated with lee waves in the midwater and around the seafloor that are 5 times greater than surrounding waters and 50 times greater than open ocean diffusivities.
Ocean Sci. Discuss., 12, 1433-1469, doi:10.5194/osd-12-1433-2015, 2015
Modeling ocean response to an extreme Bora event in Northern Adriatic using one-way and two-way atmosphere-ocean coupling
Summary: We compare the Northern Adriatic response to an extreme Bora event, as simulated by one-way and two-way atmosphere-ocean coupling. We show that two-way coupling yields significantly better estimates of heat fluxes, most notably sensible heat flux, across the air-sea interface. When compared to CTD observations in the Gulf of Trieste, two-way coupled system consequently leads to a better representation of ocean salinity, temperature, density, and even baroclinic circulation througout the event.
Ocean Sci. Discuss., 12, 1389-1431, doi:10.5194/osd-12-1389-2015, 2015
Combining operational models and data into a dynamic vessel risk assessment tool for coastal regions
Summary: A combined methodology to estimate time and space variable shoreline risk levels from ships has been developed, integrating metocean forecasts and oil spill simulations with vessel tracking automatic identification systems (AIS) and coastal vulnerability indices. Results show the ability of the proposed methodology to estimate the risk properly sensitive to dynamic metocean conditions and oil transport behaviour, enhancing the maritime situational awareness and the decision support model.
Ocean Sci. Discuss., 12, 1327-1388, doi:10.5194/osd-12-1327-2015, 2015
Influence of natural surfactants on short wind waves in the coastal Peruvian waters
Ocean Sci. Discuss., 12, 1291-1325, doi:10.5194/osd-12-1291-2015, 2015
Multi-objective entropy evolutionary algorithm for marine oil spill detection using cosmo-skymed satellite data
Summary: This study has demonstrated work to optimize the oil spill footprint detection in synthetic aperture radar (SAR) data. Therefore, Entropy-based Multi-objective Evolutionary Algorithm (E-MMGA) has implemented with COSMO-SkyMed data during the oil spill event along the coastal water of along Koh Samet island, Thailand. Besides, Pareto optimal solution is implemented with E-MMGA to minimize the difficulties of oil spill footprint boundary detection because of the existence of look-alike in SAR.
Ocean Sci. Discuss., 12, 1263-1289, doi:10.5194/osd-12-1263-2015, 2015
Factors favouring large organic production in the northern Adriatic: towards the northern Adriatic empirical ecological model
Summary: Seasonal and interannual production changes in the northern Adriatic (NA) reflect on the total Adriatic bioproduction of certain species (i.e., anchovy). Long-term (1990-2004) phyto-abundance and geostrophic currents analysis relieves basic mechanism of NA biomass production changes. The results present a first step in building an empirical ecological model of the region, aiming to predict the amount of organic production in NA, which is to be used in the environmental management of the region.
Ocean Sci. Discuss., 12, 1219-1262, doi:10.5194/osd-12-1219-2015, 2015
Ocean modelling for aquaculture and fisheries in Irish waters
Ocean Sci. Discuss., 12, 1187-1217, doi:10.5194/osd-12-1187-2015, 2015
How essential are Argo observations to constrain a global ocean data assimilation system?
Summary: Argo profiling floats are continuously sampling the world ocean, given temperature and salinity profiles up to 2000 meter depth. This article addresses the impact of the current Argo array on real time ocean analysis and forecasts. 1-year Observing System Experiments were carried out with the ¼° global Mercator Ocean monitoring and forecasting system. The improvement due to the assimilation of the Argo profiles is estimated globally and regionally, showing a significant positive impact.
Ocean Sci. Discuss., 12, 1145-1186, doi:10.5194/osd-12-1145-2015, 2015
On the observability of turbulent transport rates by Argo: supporting evidence from an inversion experiment
Summary: Results from the ECCO v4 ocean state estimate identify the constraint of fitting Argo profiles as an effective observational basis for inverse estimation of regional turbulent transport rates. The estimated parameters geography is physically plausible and exhibits close connections with the observed upper ocean ocean stratification. They yield a clear reduction in the model drift away from observations over multi-century long simulations including for independent bio-chemistry variables.
Ocean Sci. Discuss., 12, 1107-1143, doi:10.5194/osd-12-1107-2015, 2015
Impacts of mean dynamic topography on a regional ocean assimilation system
Summary: The altimetry data assimilation requires the addition of the mean dynamic topography to the altimetric sea level anomaly to match the model sea surface height. The mean dynamic topography is usually computed from the model long-term mean sea surface height. In this study, different mean dynamic topographies are used to examine their impacts on the sea level anomaly assimilation. Results show that impacts of the mean dynamic topography cannot be neglected.
Ocean Sci. Discuss., 12, 1083-1105, doi:10.5194/osd-12-1083-2015, 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. Discuss., 12, 1051-1082, doi:10.5194/osd-12-1051-2015, 2015
Increasing transports of volume, heat, and salt towards the Arctic in the Faroe Current 1993–2013
Ocean Sci. Discuss., 12, 1013-1050, doi:10.5194/osd-12-1013-2015, 2015
An improved method for the determination of dissolved nitric oxide (NO) in seawater samples
Ocean Sci. Discuss., 12, 959-981, doi:10.5194/osd-12-959-2015, 2015
The open boundary equation
Ocean Sci. Discuss., 12, 925-958, doi:10.5194/osd-12-925-2015, 2015
Sunda Shelf Seas: flushing rates and residence times
Summary: The Indonesian Sunda Shelf (average depth 48 m) is subject to many physical and biogeochemical processes with a strong impact from human activities. For investigation of marine environmental water properties, it is important to know characteristic water exchange rates. With realistic computer model results, analytical flushing rates and tracer residence times were compared for different shelf regions. Only the latter give detailed 3D pictures with times of less than 30 days to more than 2 years.
Ocean Sci. Discuss., 12, 863-895, doi:10.5194/osd-12-863-2015, 2015
Carbon-based phytoplankton size classes retrieved via ocean color estimates of the particle size distribution
Summary: Recent advances in ocean color remote sensing have allowed the quantification of the particle size distribution (and thus volume) of suspended particles in surface waters, using their backscattering signature. Here we leverage these developments and use volume-to-carbon allometric relationships to quantify phytoplankton carbon globally using SeaWiFS ocean color data. Phytoplankton carbon concentrations are partitioned among three size classes - picoplankton, nanoplankton, microplankton.
Ocean Sci. Discuss., 12, 573-644, doi:10.5194/osd-12-573-2015, 2015