We retrieved the major pigment concentrations of phytoplankton from satellite ocean color multi-spectral sensors in the Senegalo-Mauritanian upwelling, which is one of the most productive upwelling system with strong economic impacts on fisheries in Senegal and Mauritania. We processed the satellite data with a neural network classifier. This research was done through a fruitful cooperation between statisticians, specialists of neural Networks and oceanographers.

Global circulation of intermediate water masses has been extensively studied; however, its regional and local circulation along continental margins and variability and implications on sea floor morphologies are still not well known. In this study the intermediate water mass variability in the Gulf of Cádiz and adjacent areas has been analysed and its implications discussed. Remarkable seasonal variations of the Antarctic Intermediate Water and the Subarctic Intermediate Water are determined.

The bottom topography of the Baltic Sea is analysed using the new digital depth model by the European Marine Observation and Data Network (EMODnet). Analyses include depth distribution versus area, water volume, and seafloor depth variation on a km-scale. The limits for the Baltic Sea and analysed sub-basins are from HELCOM. EMODnet is compared with the previously most widely used depth model and the area of deep water exchange between the Bothnian Sea and the Northern Baltic Proper is analysed.

The Persian Gulf Water and Red Sea Water are salty and dense waters recirculating in the Gulf of Oman and the Gulf of Aden, in the form of small features. We study the life cycle of intense and small vortices and, their impact on the spread of Persian Gulf Water and Red Sea Water by using idealized numerical simulations. Small vortices are generated along the continental slopes, drift away, merge and form larger vortices. They can travel across domain and participate to the tracer diffusion.

Here we investigate the occurrence of extreme storm surges in the southern German Bight and their associated large-scale forcing mechanisms using climate model simulations covering the last 1000 years. We find that extreme storm surges are characterized by a large internal variability that masks potential links to external climate forcing or background sea level fluctuations; existing estimates of extreme sea levels based on short data records thus fail to account for their full variability.

Observations of ocean currents at two depths within the first meter of the surface are made using a large number of ocean drifters of two different draft depths (0–5 cm and 0–60 cm). We deconstruct the surface velocity measured by the drifters to calculate a purely wind-driven current in the two layers measured. We find significant velocity differences in the calculated wind-driven current between the sampled depths, which could have large implications for forecasting ocean surface transport.

Internal tides are subsurface waves generated by tidal flows over ocean ridges. When they break they create turbulence that drives an upward flux of nutrients from the deep ocean to the nutrient-poor photic zone. Measuring internal tides is problematic because oceanographic moorings are often fished-out by commercial trawlers. We show that autonomous ocean gliders and acoustic Doppler current profilers can be used together to accurately measure the amount of energy carried by internal tides.

We here present our efforts to develop a model for the Galveston Bay (besides Houston, Texas), whose hydrodynamic condition is sensitive to the adjacent Texas-Louisiana shelf condition. The model is well configured and accurate in reproducing the hydrodynamics conditions inside the bay and over the shelf. Including the broad shelf allows us to easily take into account the profound influences from major neighboring rivers, such as the Mississippi-Atchafalaya rivers.

The ocean emits the gases carbonyl sulfide (OCS) and carbon disulfide (CS2), which affect our climate. The goal of this study was to quantify at which rates both gases are produced in the Eastern Tropical South Pacific (ETSP), one of the most productive oceanic regions worldwide. Both gases are produced by reactions triggered by sunlight, but we found that the amount produced depends on different factors. Our results improve numerical models to predict oceanic concentrations of both gases.

Mesoscale eddies are ubiquitous swirling flow patterns in the open ocean with diameters of around 100 km. They transport a huge amount of heat and material and are therefore key elements of the weather of the ocean. Using satellite-based ocean surface elevation, we found that the combined global effect of all mesoscale eddies can be treated as a single strong super-vortex. This finding can be helpful to estimate the energy budget of ocean regions where only sparse field data is available.

This paper highlight the adjustment of the wave physics in order to improve the surface stress and thus the ocean/wave coupling dedicated to Iberian Biscay and Ireland domain. The validation with altimeters wave data during the year 2014 has shown a slight improvement of the significant wave height. Statistical analysis of the results of the new and old versions of the wave model MFWAM is examined for the three main ocean regions of the IBI domain.

In the North Atlantic, ocean currents transport warm waters northward in the upper water column, and cold waters southwards at depth. This circulation, not easily measured in situ, is here obtained from surface data and thermodynamics theory. Its driving role in recent temperature changes (1993–2017) in the North Atlantic is evidenced, and predictions of near-future variability (5 years) are provided and discussed.

In this paper we present a gas equilibrator that can be used to extract gases continuously or in discrete samples from seawater. The head space is analysed by a commercially available Proton Transfer Reaction - Mass Spectrometer. This allows measurement of a broad range of dissolved gases up to a very high solubility in seawater. The main advantage of this equilibrator lies in it's unique design and ease of reproducibility.

The present study describes the surface distribution of the partial pressure of CO₂ in the continental shelf of the eastern Gulf of Cádiz. For this, eight oceanographic cruises were carried out between March 2014 and February 2016. This distribution presents a linear dependence with the temperature and it decreases with distance from the coast. The Gulf of Cádiz acts as a sink of CO₂ with a mean value for the study period of −0.18 ± 20 1.32 mmol m⁻² d⁻¹.

This work highlights the relevance of coupling wave model with ocean model in order to improve key surface ocean parameters and in general to better describe the ocean circulation at small and large scale. The results focus on the Iberian Biscay and Ireland ocean region with fine grid resolution of 2.5 km for the ocean model. The main conclusion is the improvement of wave physics induces a better ocean mixing at the upper layer and a positive impact for sea surface height in storm events.

This study is focused on water exchange between the Sea of Azov and the Black Sea. The Sea of Azov is a small and freshened sea that receives a large freshwater discharge and, therefore, can be regarded as a large river estuary connected by narrow Kerch Strait with the Black Sea. In this work we show that water transport through the Kerch Strait is governed by wind forcing and do not show dependence on river discharge rate to the Sea of Azov on intra-annual time scale.

A new high resolution ocean model at 1.5 km has replaced the 7 km system for delivering short term forecasts of the North-West European shelf Seas. The products, temperature, salinity, currents, sea surface height, are available on the Copernicus Marine Service catalogue. This study is focus on the high resolution impact on the quality of the products delivered to the users. Results show that the high resolution model is better resolving the variability of the physical variables.

Estuaries are areas where riverine and oceanic waters meet and mix. The exchange flow of an estuary describes the water properties of the inflowing and outflowing water. These can be described by simple bulk values for volume fluxes and salinities. This work focuses on the numerics of one computational method for these values, the Total Exchange Flow. We show that only the so called dividing salinity method is able to reliably calculate the correct values, even for complex situations.

Highlights: Documented role of oceanic cyclonic eddies in modifying track and life cycle of cyclone by way of abrupt track reversal and rapid decay. Cyclone-induced increase in the chlorophyll a biomass ranged from 5 to 7 fold, while the net primary productivity from 2.5 to 8 fold. A 3.7 fold increase in cyclone-induced CO₂ out-gassing indicative of the altering regional CO₂ balance in the BoB, which is a weak sink.

The assimilation of satellite SST data into ocean models is complex. The temperature of the thin uppermost layer that is measured by satellites may differ from the much thicker upper layer used in numerical models, leading to biased results. This paper shows how canonical correlation analysis can be used to generate observation operators from existing datasets of model states and corresponding observation values. This type of operator can correct for near-surface effects when assimilating SST.

In this study we investigated the variability of the Arctic Front (AF), an important biologically productive region in the Norwegian Sea, using a suite of satellite data, atmospheric reanalysis and a regional coupled ocean-sea ice data assimilation system. We show evidences of the two-way interaction between the atmosphere and the ocean at the AF. The North Atlantic Oscillation is found to influence the strength of the AF and may have a profound influence on the region’s biological productivity.

The sandy seafloor in shelf seas is constantly overturned by waves and currents but also by a large number of animals searching for shelter and food. By taking a close look at the seafloor surface with the help of a laser scanner, this study evaluates their contribution to the overall reworking of sediment: It makes up as much as 14 % of the physically driven reworking. The activity of the organisms varies with the seasons and between different locations and can be estimated from physical values.