This study investigates the effects of the wave–current interactions in a region where episodes of strong cross-shelf wind occur. To do so, a coupled system between two numerical models has been implemented. The results do not show substantial differences in the water current patterns, but a clear effect on the water column stratification has been found. Additionally, stronger impact is observed for the wave period rather than the wave height.

Use of CFCs as oceanic transient tracers is difficult for recently ventilated water masses as their atmospheric mole fractions have been decreasing. To explore novel tracers, we synthesized consistent annual mean atmospheric histories of HCFC-22, HCFC-141b, HCFC-142b, HFC-134a, HFC-125, HFC-23, PFC-14 (CF4) and PFC-116 in both hemispheres and reconstructed their solubility functions in water and seawater. This work is also potentially useful for tracer studies in a range of natural waters.

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

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

With an ocean frontogenetic function, the frontogenesis of the Angola–Benguela Frontal Zone (ABFZ) is investigated. On an annual-mean timescale, the meridional confluence of Angola and Benguela currents and tilting effect due to the upwelling are the main sources to generate the ABFZ. The annual cycle of the ABFZ is also mainly driven by these two effects.

The reproductivity and predictability of mesoscale eddies in the northern South China Sea are investigated with a focus on two anticyclonic eddies based on an assimilated system. The results show that generation, evolution, and propagation paths of these two eddies can be well reproduced and forecasted when the observed amplitude >8 cm. However, when their amplitudes are <8 cm, the generation and decay of these two mesoscale eddies cannot be well reproduced and predicted by the system.

A quantitative definition for the coastal border isotropy of met-ocean processes is proposed. Wind velocity and significant wave height anisotropies are examined along four transects at the north-western Mediterranean coast. Both decrease offshore, determining a coastal fringe of width of 2–4 km. The joint probability structure reflects a decoupling near the coast and a stronger dependence in the bay-like part, where the wave field is being more actively generated by the overlaying wind.

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 phytoplankton dynamics on a daily and basin scale. The multi-sensor output compares well to data collected during dedicated field cruises, proving that the operational product can be successfully used for environmental monitoring.

We used a computer model to help predict how changing sea levels around Australia will affect the ebb and flow of the tide. We found that sea-level rise and coastal flooding affect where energy from the tide is dissipated and how the tide flows around the coastline. We found that we must consider how sea-level rise will affect tides across the rest of the world, as that will have an impact on Australia too. This sort of investigation can help direct coastal management and protection efforts.

Connections between Long Island Sound (LIS) water temperature variability and modes of tropical sea surface temperature (SST) variability have yet to be explored. It is shown that intense LIS cold-water temperature events are related to central equatorial Pacific SSTs. The decay phase of such events may be related to canonical El Niño events. Furthermore, a ridge–trough atmospheric pattern related to LIS water temperature variability fluctuates coherently with central equatorial Pacific SSTs.

Earth observation satellites routinely monitor sea-surface temperature. However, they require in situ references for calibration and validation. To support this step, drifting buoys carrying sensors with improved calibration were deployed. This paper finds that sea state and immersion depth are important to better understand the buoy measurements. A new drifting buoy was designed as a result, in the framework of the European Union Copernicus program, with an accuracy found to be within 0.01 °C.