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.

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.

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).

Diatoms are a group of phytoplankton species responsible for ~ 25 % of primary production on Earth. Ocean acidification (OA) could influence diatoms but the key question is if they become more or less important within marine food webs. We synthesize OA experiments with natural communities and found that diatoms are more likely to be positively than negatively affected by high CO² and larger species may profit in particular. This has important implications for ecosystem services diatoms provide.

A new high-resolution ocean model at 1.5 km has replaced the 7 km system for delivering short-term forecasts of the North-West European Shelf seas. The products (temperature, salinity, currents, and sea surface height) are available on the Copernicus Marine Service catalogue. This study focuses on the high-resolution impact on the quality of the products delivered to the users. Results show that the high-resolution model is better at resolving the variability of the physical variables.

This study investigates the resolving capabilities of the DUACS gridded products delivered through the CMEMS catalogue. Our method is based on the noise-to-signal ratio approach. While altimeter along-track data resolve scales on the order of a few tens of kilometers, we found that the merging of these along-track data into continuous maps in time and space leads to effective resolution ranging from ~ 800 km wavelength at the Equator to 100 km wavelength at high latitude.

The Copernicus Marine Service (CMEMS) provides oceanographic products and services. Using a mesoscale eddy tracker, we evaluate the performance of three CMEMS model products in the western Mediterranean. Performance testing provides valuable feedback to the model developers. The eddy tracker allows us to construct 3-D eddy composites for each model in the Alboran Sea gyres. Comparison of the composites with data from Argo floats highlights the importance of data assimilation for these models.

The ocean emits the gases carbonyl sulfide (OCS) and carbon disulfide (CS₂), which affect our climate. The goal of this study was to quantify the rates at which both gases are produced in the eastern tropical South Pacific (ETSP), one of the most productive oceanic regions worldwide. Both gases are produced by reactions triggered by sunlight, but we found that the amount produced depends on different factors. Our results improve numerical models to predict oceanic concentrations of both gases.

Methane seepage from the seafloor west of Svalbard was investigated with a fast-response membrane inlet laser spectrometer. The acquired data were in good agreement with traditional sparse discrete water sampling, subsequent gas chromatography, and with a new 2-D model based on echo-sounder data. However, the acquired high-resolution data revealed unprecedented details of the methane distribution, which highlights the need for high-resolution measurements for future climate studies.

The assimilation of satellite SST data into ocean models is complex. The temperature of the thin uppermost layer that is measured by satellites may differ from the much thicker upper layer used in numerical models, leading to biased results. This paper shows how canonical correlation analysis can be used to generate observation operators from existing datasets of model states and corresponding observation values. This type of operator can correct for near-surface effects when assimilating SST.

This work uses high-resolution ocean model data to quantify the sinking of waters in the subpolar North Atlantic. The largest amount of sinking is found at the depth of maximum AMOC at 45° N below the mixed layer depth, and 90 % of the sinking occurs near the boundaries in the first 250 km off the shelf. The characteristics of the sinking (total amount, seasonal variability, and vertical structure) vary largely according to the region considered, revealing a complex picture for the sinking.

After 10 years of research and development, validated analysis and forecasts of the main parameters of the Mediterranean Sea biogeochemistry (e.g. phytoplankton, nutrients, oxygen, pH, carbon fluxes) at high spatial and temporal resolution are provided in the frame of the EU Copernicus Marine Environment Monitoring Service. Along with a traditional skill performance assessment, novel metrics exploiting the Biogeochemical Argo floats data are designed to estimate the forecasts uncertainty.