Dissolved organic carbon (DOC) is the largest OC pool in the ocean. Its dynamics are largely influenced by hydrodynamic mixing of different water masses in the East China Sea and Kuroshio Extension. Water from Kuroshio intrusion could dilute DOC in the shelf break of the ECS, and spatial variations of DOC in upper 700 m in the KE were mainly influenced by mixing of the Kuroshio and Oyashio currents. The study provides updated and useful information for understanding DOC cycles in the ECS and KE.

Two gridded sea surface salinity (SSS) products have been derived from the European Space Agency’s Soil Moisture and Ocean Salinity mission. The uncertainties of these two products in the Arctic are quantified against two SSS products in the Copernicus Marine Environment Monitoring Services, two climatologies, and other in situ data. The results compared with independent in situ data clearly show a common challenge for the six SSS products to represent central Arctic freshwater masses (<24 psu).

This paper deals with sea level altimetery products. These geophysical data are distributed as along-track and gridded data through Copernicus programs CMEMS and C3S. We present in detail a new reprocessing of the data (DT2018) from 1993 to 2017. The main changes and their impacts since the last version (DT2014) are carefully discussed. This comparison is made using an independent dataset. DT2018 sea level products are improved at the global and regional scale, especially in coastal areas.

The present study describes the surface distribution of the partial pressure of CO₂ in the continental shelf of the eastern Gulf of Cádiz. For this, eight oceanographic cruises were carried out between March 2014 and February 2016. This distribution presents a linear dependence with the temperature and it decreases with distance from the coast. The Gulf of Cádiz shows a mean rate of −0.18 ± 1.32 mmol m^-2 d^-1, with an annual uptake capacity of CO₂ of 4.1 Gg C year^-1.

Satellite wind data were used to understand surface wind variability in the eastern austral Pacific Ocean, a region dominated generally by strong westerlies, but the empirical orthogonal function demonstrated that wind variability was dominated by a synoptic scale. Nighttime heatwave events were detected to produce air temperature maxima which exceeded the normal midday maxima caused by solar radiation. Downwelling conditions prevailed in the study region due to onshore Ekman transport.

Monitoring of marine waters is currently mainly limited to low-resolution methods, while the ocean can be highly variable both in time and space. This study explores the use of two high-resolution methods to study phytoplankton dynamics and uses a model to organize the large amount of data. The results show that the combination of FRR fluorometry and flow cytometry offers an elaborate view of the phytoplankton community and can improve existing monitoring programs.

Ocean forecasting systems predict ocean water level, but the accuracy of predictions varies as a function of the forecast lead time and the dynamics causing water level variability. This study investigates the accuracy of predictions of tidal water levels in the AMSEAS forecast system, with emphasis on the small (roughly 5 cm) fluctuations associated with the baroclinic tide.

Coupled atmosphere–ocean modelling systems allow changes in the ocean to directly and immediately feed back on the atmosphere and enable improved weather prediction and ocean forecasts. This is particularly true if the coupled feedbacks are also considered in the way real-time observations of the atmospheric and oceanic states are used to obtain the initial conditions for the forecasts. Here we demonstrate promising performance from such a coupled system when used for ocean prediction.

The pelagic in situ observation system (PELAGIOS) is a towed observation system with HD video camera and environmental sensors. It is used for pelagic video transects down to 3000 m. The system enables the visualization and exploration of pelagic organisms (> 1 cm), in particular delicate gelatinous fauna, which cannot be captured by nets. The video and hydrographic data give insight into the biodiversity, abundance, and distribution of oceanic pelagic organisms from the surface to the deep sea.

The Galápagos Archipelago and Galápagos Marine Reserve are among the world's most iconic wildlife refuges. Yet, plastic litter is now found even in this remote archipelago. It is unclear where this plastic originates from. In this study, we show that remote coastal sources of plastic pollution are fairly localized and limited to South American and Central American coastlines. Identifying how plastic ends up in the Galápagos aids integrated management opportunities to reduce plastic pollution.

Analyses of ocean tides are based on the separation of the tidal signal into constituents with different periodicities. We prepare a constituents list for the operational usage of a tidal prediction method called harmonic representation of inequalities. A frequency analysis is applied to data from 111 tide gauges. The new list consists of 39 entries. This is four constituents less than previously used. Comparisons with observations suggest that it leads to slightly improved tidal predictions.

Global circulation of intermediate water masses has been extensively studied; however, its regional and local circulation along continental margins and variability and implications on sea floor morphologies are still not well known. In this study the intermediate water mass variability in the Gulf of Cádiz and adjacent areas has been analysed and its implications discussed. Remarkable seasonal variations of the Antarctic Intermediate Water and the Subarctic Intermediate Water are determined.