This work investigates the seasonal variations of M₂, S₂, K₁, and O₁ at E2 and Dalian. At E2, the M₂ amplitude and phase lag reach maximum in summer and minimum in winter. The S2 and K1 amplitudes show annual cycles, while the phase lags of S₂, K₁, and O₁ had semi-annual cycles. The seasonal variations at Dalian are different from those at E2, except for M₂ phase lag. The seasonal variations at E2 are induced by seasonality of vertical eddy viscosity, while those at Dalian cannot be explained.

This study is focused on water exchange between the Sea of Azov and the Black Sea. The Sea of Azov is a small 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 does not depend on the river discharge rate to the Sea of Azov on an intra-annual timescale.

Due to climate change, an accelerated mean sea level rise is expected. Numerical hydrodynamic models help to understand how mean sea level rise changes tidal dynamics. One limiting factor is the resolution of the model grid. In this study we show that especially in flat coastal areas such as the Wadden Sea in the German Bight the representation of the bathymetry plays a crucial role for the estimation of changed tidal dynamics in response to mean sea level rise.

We used a simple nitrogen-based box model to estimate production in the coastal northern Gulf of Mexico and off the west of the Korean Peninsula, which receive nitrogen in different forms. The Gulf of Mexico gets almost all its nitrogen from rivers, while atmosphere and groundwater discharges are also contributed in Korea. Production in both areas decreased away from river mouths, and we identified three zones with different productivity that vary in size as river flow and other factors change.

We characterized the water masses of the Senegalese Petite Côte and described spatial and temporal variations of SSLs in relation to their environment. SSL distributions were mainly structured by bottom depth, diel period, and the level of vertical stratification in the water column. This study serves as a precursor in the field of SSL study in the Senegalese Petite Côte and even West African coasts, hence the importance of this work.

The ocean is one of the important components of the ocean–atmosphere coupling system. Sea surface temperature (SST) is the basis for the interaction between the ocean and the atmosphere, and it characterizes the combined results of ocean heat and dynamic processes. The variability of SST in the northwest Pacific has been studied on seasonal, annual and interannual scales based on the monthly datasets of ERSST and OISST.

The region south of Cape Farewell (SCF) is recognized as a deep convection site. Convection deeper than 1300 m occurred SCF in 2015 and persisted during three additional winters. Extreme air–sea buoyancy fluxes caused the 2015 event. For the following winters, air–sea fluxes were close to the climatological average, but local cooling above 800 m and the advection below 1200 m of a fresh anomaly from the Labrador Sea decreased stratification and allowed for the persistence of deep convection.

The study evaluates how much bioavailable nitrogen is contributed to the nitrogen budget of the western Baltic Sea by deposition of shipping-emitted nitrogen oxides. Bioavailable nitrogen compounds are nutrients for phytoplankton (algae). Excessive input of nutrients into water bodies may lead to eutrophication: more algal blooms with subsequently more oxygen limitation at the seafloor. Hence, reducing shipping emissions might reduce the anthropogenic pressure on the marine ecosystem.

Nitric oxide (NO) could be produced by nitrite photolysis; the rates from dissolved nitrite in artificial seawater showed increasing trends with decreasing pH, increasing temperatures, and increasing salinity. However, NO photoproduction from the natural seawater samples did not show correlations with pH, water temperature, salinity, or dissolved nitrite concentrations in the western tropical North Pacific Ocean (WNTP). And there were other NO loss processes in the surface layer of WNTP.

The Red Sea holds one of the most diverse marine ecosystems in the world, although fragile and vulnerable to ocean warming. To better understand the long-term variability and trends of temperature in the whole water column, we produce a 3-D gridded temperature product (TEMPERSEA) for the period 1958–2017, based on a large number of in situ observations, covering the Red Sea and the Gulf of Aden.

In a strong global warming scenario, declining nutrient concentrations of Atlantic water masses flushing the NWES lead to a reduction in the biological productivity on the shelf. We show that meltwater discharge from the Greenland ice sheet induces a change in the subpolar ocean circulation, resulting in a nutrient increase of deeper Atlantic water masses. These are mixed up at the shelf break and spread over the shelf, mitigating both the expected nutrient decline and productivity reduction.

Sustainable operation of floating solar platforms requires knowledge of effects on the marine ecosystem. We modelled effects on water flow and algae growth in a coastal sea. Algae growth was reduced depending on the local currents and on the density of coverage with platforms. The model represented platforms distributed evenly over areas of hundreds of square kilometres. For smaller-scale cases, effects may be smaller, and for more detailed understanding, three-dimensional models are needed.

The Caspian Sea is the largest enclosed basin on Earth and a unique subject for the analysis of the tidal dynamics. Using numerical modelling, we examine details of the spatial and temporal features of the tidal dynamics in the Caspian Sea. We present tidal charts of the amplitudes and phase lags of the major tidal constituents. The maximum tidal range, of up to 21 cm, has been found in Turkmen Bay. The tidal currents in this area have speeds of up to 22 cm s^-1.

After 2007 ²³⁰Th decreased significantly in the central Amundsen Basin. This decrease is accompanied by a circulation change, indicated by changes in salinity. Ventilation of waters is most likely not the reason for the observed depletion in ²³⁰Th as atmospherically derived tracers do not reveal an increase in ventilation rate. It is suggested that these interior waters have undergone enhanced scavenging of Th during transit from Fram Strait and the Barents Sea to the central Amundsen Basin.

We carried out a literature review and an opinion poll of the JERICO-NEXT community to identify the main environmental threats in European coastal areas and gaps in monitoring. The need for improved monitoring was highlighted, e.g. through improved design and monitoring effort and better links with new technologies. The findings underpin the JERICO-NEXT science strategy to integrate linkages between physical, chemical, and biological parameters to address scientific and policy needs.

Nutrient-rich water is moved to the surface near continental margins. Then it forms rich but difficult to observe spatial structures of physical and biological/biogeochemical properties. Here we present a high resolution (2.5 km) section through such features obtained in May 2018 with a vehicle towed behind a ship. Considering that such interactions of physics and biology are common in the ocean, they likely strongly influence the productivity of such systems and their role in CO₂ uptake.