Measurements of ocean currents, stratification and microstructure collected northwest of Svalbard are used to characterize the evolution of the warm Atlantic current. The measured turbulent heat flux is too small to account for the observed cooling rate of the current. Estimated contribution of diffusion by eddies could be limited to one half of the observed heat loss. Mixing in the bottom boundary layer, driven by cross-slope flow of buoyant water, can account for the remaining heat loss.

Time series of vertical profiles of hydrophysical parameters and oxygen are critical for identifying trends in ventilation in the NE Black Sea. Such frequent measurements were performed using a moored profiler over the continental slope in winter 2016. For a brief period of time, the hypoxia onset depth rose to 97 m, the highest elevation ever recorded. Whereas the shelf edge depth in this region usually ranges from ~ 100 m there is a risk of spreading of hypoxic bottom-water to the outer shelf.

The Arctic Ocean is changing rapidly. In order to track these changes, we developed and deployed a long-term marine ecosystem observatory in the Chukchi Sea. It helps us to better understand currents, waves, sea ice, salinity, temperature, nutrient and carbon concentrations, oxygen, phytoplankton blooms and export, zooplankton abundance and vertical migration, the occurrence of fish and marine mammals throughout the year, even during the ice covered winter months.

Ocean surface waves generated by wind and dissipated by white-capping are two important physics processes for numerical wave simulations. In this study, a new pair of wind-wave generation and dissipation source functions is implemented in a wave model SWAN, and it shows better performance in real wave simulations during two North Sea storms. The new source functions can be further used in other wave models for both academic and engineering purposes.

The use of chlorofluorocarbons as oceanographic transient tracers is difficult for recently ventilated water masses as their atmospheric concentrations have been decreasing. To explore and evaluate novel tracers, we have synthesize consistent atmospheric concentrations histories of HCFC-22, HCFC-141b, HCFC-142b, HFC-134a, HFC-125, HFC-23, PFC-14 and PFC-116 in both hemispheres and reconstruct their solubility functions in seawater. The method for reconstruction can work for more compounds.

The increase of data quality of wind and wave measurements provided by the new Sentinel-3A satellite in coastal areas is demonstrated compared to measurements of older satellites with in situ data and spectral wave model simulations. The sensitivity of the wave model to wind forcing is evaluated using data with different temporal and spatial resolution, where an hourly temporal resolution is necessary to represent the peak of extreme events better.

Relative sea-level rise is traditionally measured using tide gauges, but we question the reliability of tide-gauge data in low-elevation coastal zones. Examining benchmarks, we find that tide gauges typically do not record subsidence occurring in the shallow subsurface and thus underestimate rates of relative sea-level rise. We present an alternate method of measuring relative sea-level rise and conclude that low-elevation coastal zones may be at higher risk of flooding than previously assumed.

In operational oceanography, regional and local models use large-scale models (such as those run by CMEMS) for their initial and/or boundary conditions, but unfortunately there is no feedback that improves the large-scale models. The present study aims at replacing normal 2-way nesting by a data assimilation technique. This upscaling method is tried out in the North-Western Mediterranean Sea using the Nemo model, and shows that the basin-scale model indeed benefits from the nested model.

This study uses different in-situ and satellite measurements to investigate the ocean circulation in the NW Mediterranean Sea. We analyze how the different instruments (satellite altimetry, HF radars, gliders, ADCPs) capture the current variability and how they complement each other. We demonstrate the ability of satellite altimetry to capture the fluctuations of the narrow coastal Northern Current at different time-scales. This study provides an integrated approach to a coastal dynamics study.

This work fully describes all the technical steps that are currently put in place in the context of the European Copernicus Marine Environment and Monitoring Service to make Ocean Colour data freely available to the general public. These data are useful for mapping the phytoplankton dynamics on daily and basin scale. The multi-sensor output well compares with data collected during dedicated field cruises proving that the operational product can be successfully used for environmental monitoring.

Sei whales are one of the least known baleen whales. We found them in southern Chile, on the Patagonian coasts. There we sailed on 2016 and 2017 to set hydrophones up in The Penas Gulf, to investigate how this Patagonian sei whales might be communicating. We could identify sei whale’s downsweeps calls (a type of vocalization that starts at a high frequency and ends at a lower). We found that sei whales at Penas Gulf perform calls distinctly differ from sounds previously described.

In our manuscript, new versions of simplified mathematical description (parameterization) of light absorption coefficients by phytoplankton suspended in surface layer of the Baltic Sea in relation to chlorophyll a concentration and concentration of accessory pigments are presented. The practical value of the simple parameterizations presented in this work should be seen in the opportunities for applying them to the development of remote sensing methods.

In a double tide the ocean reaches high or low tide, starts to fall or rise, only to go back to a new high or low. Here, we describe three ways this can happen by dividing locations with observed double tides into three classes. This showed that double tides are more common than we thought, and more complicated than most textbooks claim because they only describe one class of double tides. This matters to shipping, coastal flood management, and other disciplines interested in sea-level change.

This paper is motivated by the next SWOT altimetric mission dedicated to the observation of meso and submesoscale oceanic features. It focuses on tropical area where it exists a strong discrepancy in their spectral signature between altimetry and models. The paper review the spectral signature of tropical turbulence that present a rich variety of phenomenons depending on the latitudinal dependance of the Coriolis force. Internal tides observed by altimetry explain the discrepancy with the model.

We found that refining the spatial resolution of nitrogen deposition data had low impact on marine nitrogen compounds compared to the impact by nitrogen deposition data sets of different origin (other model). The shipping sector had a contribution of up to 10 % to the marine dissolved inorganic nitrogen.

Time-series observation can reveal processes and controlling factors underlying production and loss of iodocarbons in the ocean and provide data for testing hypotheses/models. Here, we report weekly observations of iodocarbons from May 2015 to Dec. 2017 at 4 depths in Bedford Basin, Canada. Iodocarbon in near-surface waters showed strong seasonal variability and similarities and differences in their correlation with temporal variations of potentially-related properties and causal factors.

Drag coefficient is not a constant because it is an increasing function of wind speed so we chose to check the differences between the relevant parameterizations for drag coefficient for momentum transfer values in the North Atlantic and the European Arctic. We show that the choice of drag coefficient parameterization can lead to significant differences in resultant momentum flux (or wind stress) values. The differences between the highest and lowest parameterizations may be 14 % in the Arctic.

The paper explored applicability of Landsat OLI sensor for monitoring concentration and movement of suspended particles along coastal landscape of Thiruvananthapuram. Suspended sediments moved north-south during post monsoon and reversed their direction during post monsoon season under the influence of monsoon winds. The findings revealed that the sediment concentration decreased rapidly with the increase in distance to the beach and depth to the seabed.