'''This product has been archived''' '''Short description:''' Arctic sea ice thickness from merged SMOS and Cryosat-2 (CS2) observations during freezing season between October and April. The SMOS mission provides L-band observations and the ice thickness-dependency of brightness temperature enables to estimate the sea-ice thickness for thin ice regimes. On the other hand, CS2 uses radar altimetry to measure the height of the ice surface above the water level, which can be converted into sea ice thickness assuming hydrostatic equilibrium. '''DOI (product) :''' https://doi.org/10.48670/moi-00125

The abundance of ichthyoplankton in samples from dedicated plankton surveys by Cefas with positional and sample data. Surveys took place off the Western Coast of the UK and Ireland between 1986 and 2004. Series of cruises undertaken to contribute to the estimation of the spawning stock biomass of the western mackerel and horse mackerel stocks by plankton survey. The triennial mackerel egg surveys were begun in 1977 to estimate the SSB of the western mackerel stock. Since 1986 the surveys have also been used to estimate the SSB of horse mackerel. Plankton sampling is undertaken to estimate the egg production and trawling is carried out to estimate the mean fecundity of the mature female fish. Various designs of Gulf VII type samplers have been used with various apertures of nosecones and 270 micron nets. Samplers are now standardised to the 53cm version, fitted with 20cm aperture nosecones. Analysis at Cefas involved separating all fish eggs and larvae from samples. Where possible all eggs were identified. Eggs lacking identifiable features were measured. Where >100 eggs were found, sub-sampling was undertaken. Eggs that were unmeasured were apportioned across the size distribution of measured eggs. All mackerel and horse mackerel eggs were staged.

ROCCH, the French Chemical Contaminant Monitoring Network, regularly provides data for assessing the chemical quality of French coastal waters. Concentrations of trace metals and organic compounds are measured in integrative matrices (bivalves and sediments). Surface sediment samples are collected from 200 to 250 monitoring stations in the English Channel, the Bay of Biscay and Mediterranean lagoons every six years. Results concerning approximately 140 historical and emerging chemical substances (metals, PAHs, PCBs, PBDEs, PFAS …) are submitted to international databases of the Regional Sea Convention (OSPAR for the North East Atlantic and the Barcelona Convention for the Mediterranean) and disseminated to public stakeholders. During the ROCCHSED campaign in spring 2022, three sediment cores, each forty to fifty centimetres long, were collected from three different sites in the Bay of Biscay. Horizons of one to two centimetres in length were dated, sieved and freeze-dried for chemical analysis. The concentrations of metals, PAHs and PCBs were determined in horizons aged from over 150 years to the present in order to define the reference concentration of natural levels and describe the temporal profile of contamination.

The 4D Marine Heatwaves (MHW) atlas contains 4D (x, y, z, t) **daily temperature and marine heatwaves categories** for global region [82.875°S-89.875°N, 0.125°E-359.875°E], from 0 to 300m depth and a spatial resolution of 1/8°. It covers the period 1993-2022. The MHW atlas has been computed from the temperature 4D fields of the ARMOR3D global product delivered in the Copernicus Marine Service (MULTIOBS_GLO_PHY_TSUV_3D_MYNRT_015_012 - https://doi.org/10.48670/moi-00052 ). The MHW categories are derived from the Hobday’s method [Hobday et al.,2018]. Each MHW event is classified among four categories (moderate to extreme), identified in terms of multiples of the local difference between the 90th percentile and climatological values, and defined as moderate (1-2×, Category I), strong (2-3×, Category II), severe (3-4×, Category III), and extreme (>4×, Category IV). When the category is zero, this means that there is no MHW. The period 1993-2021 is used as a baseline for defining the climatology to be as close as possible to the 30-year period suggested by Hobday. This choice is motivated by the need of altimetry data to constrain the vertical temperature reconstruction, which is required for most ocean reanalyses as well. Additionally, ancillary data are provided together with the data. It consists of 4D daily **temperature climatology** and **90 percentiles of the temperature**. These fields have been used to compute the MHW categories. They are delivered over the same domain as the MHW atlas. ARMOR3D **temperature uncertainties** are also supplied as they can help users to select only the most reliable events in the database. This dataset was generated by CLS (Collecte Localisation satellite) and is distributed by Ifremer /CERSAT in the frame of the CAREHeat project (CAREHeat Website) funded by the European Space Agency (ESA).

Seasonal Climatology of Silicate for Loire River for the period 1965-2019 and for the following seasons: - winter: January-March, - spring: April-June, - summer: July-September, - autumn: October-December Observational data span from 1965 to 2019. Depth levels (m): -125.0, -100.0, -75.0, -50.0,-40.0, -30.0, -25.0, -20.0, -15.0, -10.0, -8.0, -6.0, -4.0, -2.0, -0.0 Data Sources: observational data from SeaDataNet/EMODNet Chemistry Data Network. Description of DIVAnd analysis: The computation was done with the DIVAnd (Data-Interpolating Variational Analysis in n dimensions), version 2.7.4, using GEBCO 30sec topography for the spatial connectivity of water masses. The horizontal resolution of the produced DIVAnd maps grids is 0.01 degrees. Correlation length was optimized and filtered vertically and a seasonally-averaged profile was used. Signal to noise ratio was fixed to 1. Logarithmic transformation applied to the data prior to the analysis. Background field: the data mean value is subtracted from the data. The weight of time series was decreased by a factor of 10 relative to the weight of the profiles to account for the redundancy in the time series observations. Detrending of data: no, Advection constraint applied: no. Units: umol/l.

MISSION ATLANTIC assesses the whole Atlantic, and ecosystem components at risk from natural hazards and the consequences of human activities, including individual regional Case Studies, and their interconnectivity. To do this, Mission Atlantic develops IEAs for seven regional Case Studies, in sub-Arctic and Tropical regions of the Atlantic Ocean, ranging from shelf seas to the mid-Atlantic Ridge: 1) Norwegian Sea 2) Celtic Sea 3) Canary Current 4) North Mid Atlantic Ridge 5) South Mid Atlantic Ridge 6) Benguela Current 7) South Brazilian Shelf