The Sea of Japan, surrounding Russia, the Korean Peninsula, and the Japanese Archipelago, is one of the most rapidly changing seas in the world. We measured carbon and nitrogen isotope ratios of zooplankton. We determined that the carbon stable isotope ratio has been decreasing over 15 years, and this trend was comparable to or slightly more rapid than the Suess effect, which is a signal of anthropogenic disturbance. Therefore, carbon dynamics are changing in the shallow coastal waters.

Spectacular climatic phenomena such as El Nino—La Nina oscillations are connected with large-scale rearrangements of oceanic surface flow patterns. In order to get a better insight into the dynamics of such changes, we performed numerical experiments on the advection of 6600 water parcels in the focal area. Surface flow fields were taken from the AVISO data bank. A simple stochastic model (fractional Brownian motion) with only two parameters nicely reproduced the statistics of advection.

In this study, we present visible direct evidence for Al occurrence in biogenic silica (BSi). Homogeneous distribution of Al was shown in BSi, and the average Al / Si atomic ratio was 0.011. Considering structural Al has dissolution–inhibition for BSi, the fundamental results not only indicate the significant contribution of marine diatoms to the biogeochemical migration of marine Al, but also imply the contribution mechanism of Al on the carbon sequestration of marine diatoms.

We validate the recent ALES-reprocessed coastal satellite altimetry dataset along the Norwegian coast between 2003 and 2018. We find that coastal altimetry and conventional altimetry products perform similarly along the Norwegian coast. However, the agreement with tide gauges slightly increases in terms of trends when we use the ALES coastal altimetry data. We then use the ALES dataset and hydrographic stations to explore the steric contribution to the Norwegian sea-level anomaly.

Spectral analyses showed the importance of the blue, green, and NIR wavelengths for submerged aquatic vegetation (SAV) discrimination. Moreover, the integration of the blue or the green bands in water vegetation indices (WVIs) increases their discriminating power of SAV. Statistical fits between homologous bands of Sentinel-SMI and Landsat-OLI revealed excellent linear relationships (R² of 0.999) with insignificant RMSD (≤ 0.0015). Accordingly, MSI and OLI sensors are spectrally similar.

A turbulence instrument was installed on a light autonomous underwater vehicle (AUV) and deployed in the Barents Sea in February 2021. We present the data quality and discuss limitations when measuring turbulence from the AUV. AUV vibrations contaminate the turbulence measurements, yet the measurements were sufficiently cleaned when the AUV operated in turbulent environments. In quiescent environments the noise from the AUV became relatively large, making the turbulence measurements unreliable.

The Baltic Sea is predicted to freshen in the future. To explore the effect of decreasing salinity on N₂ fixers, we followed the natural salinity gradient in the Baltic Sea from the Kiel Fjord to the Gotland Basin and identified an N₂ fixer community dominated by Nodularia and UCYN-A. A salinity threshold was identified at a salinity of 10, with Nodularia dominating at low and UCYN-A dominating at higher salinity, suggesting a future expansion of Nodularia N₂ fixers and a retraction of UCYN-A.

Ocean surface waves forced by tropical cyclones can cause tremendous damage to offshore structures and coastal communities. As such, forecasting their evolution is of utmost importance. This study investigates the usage of a long short-term memory neural network to forecast hurricane-forced waves in the Caribbean Sea. Results strongly suggest that forecasts can be performed to a high degree of accuracy up to 12 h at minimal computational expense and even outperform a wave model.

Organic carbon in the oceans can take various paths: it may e.g. sink to the sediment, be eaten, or be recycled to start all over again. Where carbon ends up for how long has implications for atmospheric CO₂ concentrations and our climate. To assess which pathways exist and how they are structured, we introduce a qualitative concept of organic carbon pathways. This concept helps to identify pathways, compare ecosystems, and assess how human actions and environmental changes alter pathways.

We provide the first insights on bio-optical processes in Storfjorden (Svalbard). Information on factors controlling light propagation in the water column in this arctic fjord becomes crucial in times of rapid sea ice decline. We find a significant contribution of dissolved matter to light absorption and a subsurface absorption maximum linked to phytoplankton production. Dense bottom waters from sea ice formation carry elevated levels of dissolved and particulate matter.

The signature of internal tides has become an important component for high-resolution altimetry over oceans. Several studies have proposed some solutions to resolve part of these internal tides based on the altimetry record. Following these studies, we propose here a new inversion approach aimed to mitigate aliasing with other dynamics. After a description of the methodology, the solution for the main tidal components has been successfully validated against independent observations.

The mistral winds are believed to be the primary source of cooling of the Gulf of Lion, leading to deep convection in the region, a process that mixes the ocean column from the seafloor to the sea surface. However, we have found that seasonal atmospheric changes also significantly cool the Gulf of Lion waters to cause deep convection, rather than mistral winds being the sole source, contributing roughly two-thirds of the required cooling, with the mistral winds contributing the final third.

We have collated multiple sources of tide gauge data for Dublin Port, and subsequently corrected them for bias. We have then shown that these corrected mean sea level measurements agree with nearby tide gauges to a far higher degree than the raw data. A longer-term comparison with Brest and Newlyn also indicates overall agreement. Our final adjusted dataset estimated the rate of sea level rise to be 1.1 mm/yr between 1953 and 2016 and 7 mm/yr between 1997 and 2016 at Dublin Port.

Ocean heat and carbon content increase proportionately as the planet warms. However, circulation changes in response to changing heat content, redistributing preindustrial heat, carbon, and salinity fields. Redistribution leaves properties unchanged, so we may leverage our skill identifying preindustrial carbon in order to trace preindustrial heat and salinity field redistribution. Excess salinity opposes excess-temperature-induced density change, and redistribution grows continually.

The European Slope Current (SC) is a northward-flowing current running parallel to the UK coastline. It is forced by changes in the density gradient of the wider North Atlantic Ocean. As the North Atlantic has warmed since the late 1990s, these gradients have changed strength and moved, reducing the volume and speed of water feeding into the SC. The SC flows into the North Sea, where changes in the species distribution of some plankton and fish have been seen due to the warming inputs.