This study targets high-resolution, diatom-specific sedimentary ancient DNA using a DNA metabarcoding approach. Diatom DNA is preserved with substantial taxonomic richness in the eastern Fram Strait over the past 30,000 years with taxonomic composition being dominated by cold-water and sea-ice associated diatoms. Taxonomic re-organizations took place after the Last Glacial Maximum and after the Younger Dryas. Peak proportions of pennate diatoms might indicate past sea-ice presence.

Satellite observations of the ocean were combined with a numerical model to create simulations of the ocean state between 1998-2010. Relationships between physical and biogeochemical quantities were assessed, to investigate whether observations of different variables are consistent in their representation of the Earth System. Good consistency was found. The results also highlighted ways in which the model could be improved, and the respective impacts of using different observations.

The ocean is an important source of nutrients and organisms to coastal waters, but it is not clear what controls current flow between the deep ocean and the coast. We contrasted ocean flow pathways and coastal water properties between summer 2013 and a series of intense storms in December 2013. Further, we assessed the likelihood of storms occurring over the North Atlantic during each winter. We found that local weather patterns exert a strong influence on coastal water properties and origins.

Observations in the Nordic Seas have shown a general warming and an increase in sea surface height over the last few decades. However, our results reveal that the sea surface heights and heat content in the decade following the mid-2000s have not risen much or even stagnated. This is most prominent in the eastern Nordic Seas, where waters of Atlantic origin dominate. We conclude that this stagnation is possibly a consequence of decreased heat transport from the Subpolar North Atlantic.

Seagrass, as plants, need light for photosynthesis and production.This study measured the changes in productivity and light in a back-barrier estuary, and connected those changes with the type of seabed within the estuary. We found that the locations with seagrass on the seabed had more light getting through the water and higher productivity, because of the way seagrass keeps sediment on the seabed during wave events. When sediment stays on the bed, it cannot reduce the light in the water.

The ocean circulation is crucial for the climate and the North Atlantic subpolar gyre is a key component of the meridional heat transport. In this study we use a high resolution simulation with bottom following coordinates to investigate the gyre dynamics. We show that non-linear processes, underestimated in most climate models, control the circulation in the gyre interior. This result contrasts with the classical theory putting forward the wind effects on the large scale circulation.

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.

Observations of transient tracer distribution provide essential information on ocean ventilation. The use of several commonly used transient traces is impeded as their atmospheric mole fractions are decreasing with time. Here we explore new potential oceanic transient tracers with a novel analytical system that simultaneous measures a large range of compounds. Combined with the known atmospheric history and seawater solubility we discuss the utility of selected HCFC, HFC and PFC as tracers.

Coastal regions play a significant role in global processes. Numerical models are one of the major instruments in understanding ocean dynamics. The main objective of this article is to demonstrate the representativeness of the simulations with the new FESOM-C model by comparing the results with observational data for the southeastern part of the North Sea. An equally important objective is to present the application of convergence analysis of solutions for grids of different spatial resolutions.

The diel vertical migration of zooplankton considered the largest daily migration of biomass on earth. This study investigates zooplankton distribution, dynamics and factors controlling them during open water and ice cover periods in Hudson Bay, a large, seasonally-ice covered Canadian inland sea. The presented data constitutes a first-ever observed presence of diel vertical migration of zooplankton in Hudson Bay during winter as well as its interaction with the tidal dynamics.

Our main aim is to study the feasibility of reconstructing oceanic currents extending the data obtained from coastal multiplatform observatories to nearby areas in 3D in the SE Bay of Biscay. To that end, two different data-reconstruction methods with different approaches were tested, providing satisfactory results. This work is a first step towards the real applicability of these methods in this study area and shows the method’s capabilities for a wide range of applications.

This paper focuses on internal tides in the marginal Solomon Sea where LLWBCs transit. The objective is to characterise such internal tides and to give som insights on their impacts on water mass transformation in this area of interest for the global circulation. Results are discussed for two contrasted ENSO conditions with different mesoscale activity and stratification. Such study is motivated by the next altimetric SWOT mission that will be able to observe such phenomena.