A time series of ocean circulation in the North Atlantic from 1900-2018 was calculated using a number of gridded data products. These comprise the EN4.2.1 gridded temperature and salinity dataset (Good et al. 2013), using Gouretski and Reseghetti (2010) corrections (https://www.metoffice.gov.uk/hadobs/en4/download-en4-2-1.html), gridded satellite altimetry from the Copernicus Marine Environment Monitoring Service (CMEMS, http://marine.copernicus.eu) and gridded wind stress fields from the European Centre for Medium-Range Weather Forecasts (ECMWF, https://www.ecmwf.int). Both ERA-20C and ERA-Interim products were obtained to cover the periods 1900-1978 and 1979-2018 respectively.

The Marine Autonomous Systems in Support of Marine Observations (MASSMO) campaign 4 dataset includes data collected by 8 submarine gliders, 2 wavegliders and one autonomous surface vehicle. The dataset comprises recovery version data. i.e. the data downloaded from a vehicle at the end of its mission. The data obtained from gliders operated by the University of East Anglia (UEA) is fully quality controlled. No quality control procedures have been applied to the data obtained from all other autonomous vehicles. Parameters observed include, temperature, salinity, chlorophyll fluorescence, optical backscatter, oxygen, acoustic noise and video data. The dataset was collected within the UK sector of the Faroe-Shetland Channel, focussing on the outer shelf and upper shelf. The work area had a bounding box of 58-62 degrees north and 2-9 degrees west. The MASSMO 4 campaign was run between 1st June 2017 until 7th June 2017 while platforms were deployed they were collecting data continuously. The dataset was collected using a mixture of three autonomous surface vehicles and eight submarine gliders. Glider sensor suites included CTD, bio-optics, oxygen optodes, and passive acoustic sensors. Additionally the surface vehicles were equipped with meteorological sensors and cameras. The campaign comprised a range of oceanographic data collection, but had a particular focus on passive acoustic monitoring of marine mammals and oceanographic features, and included development of near-real-time data delivery to operational data users. MASSMO 4 was co-ordinated by the National Oceanography Centre (NOC) in partnership with University of East Anglia (UEA), Plymouth Marine Laboratory (PML) and Scottish Association for Marine Science (SAMS). The mission was sponsored by Defence Science and Technology Laboratory (Dstl) and involved close co-operation with the NATO Centre for Maritime Research and Experimentation (CMRE) and UK Royal Navy, and was supported by several additional commercial, government and research partners.

Five ocean gliders were deployed during cruise SSD-024 as part of the Bay of Bengal Boundary Layer Experiment (BoBBLE), a collaborative project between India and the UK, funded jointly by Ministry of Earth Sciences (MoES), Government of India, and Natural Environmental Research Council, UK, through the “Drivers of Variability in the South Asian Monsoon” programme. The major objective of this project is to understand the east-west contrast in the upper layer characteristics of the southern Bay of Bengal and its interaction with the summer monsoon. The major observational objectives of SSD-024 were to profile the hydrography along 8°N in international waters and to carry out a 10-day time series at 8°N, 89°E. 14 scientists from India and 8 from the UK made up the scientific contingent of SSD-024. Five Seagliders were successfully deployed in the southern Bay of Bengal from ORV Sindhu Sadhana during the BoBBLE cruise. These autonomous underwater vehicles fly in a continuous repeating sawtooth pattern from the surface down to a maximum depth of 1000 m. They are all equipped with conductivity-temperature-depth (CTD) sensors. Additional sensors include dissolved oxygen, chlorophyll fluorescence and backscatter, photosynthetically active radiation (PAR) and microstructure sensors. Three Seagliders (including one microstructure enabled glider) are from the University of East Anglia (UEA), UK glider facility. The remaining two Seagliders are from the Marine Autonomous Robotics Systems (MARS) national UK facility. All five Seagliders were deployed and piloted by UEA and associated personnel.

The GEBCO_2020 Grid is a global continuous terrain model for ocean and land with a spatial resolution of 15 arc seconds. In regions outside of the Arctic Ocean area, the grid uses as a base Version 2 of the SRTM15_plus data set (Tozer, B. et al, 2019). This data set is a fusion of land topography with measured and estimated seafloor topography. Included on top of this base grid are gridded bathymetric data sets developed by the four Regional Centers of The Nippon Foundation-GEBCO Seabed 2030 Project. The GEBCO_2020 Grid represents all data within the 2020 compilation. The compilation of the GEBCO_2020 Grid was carried out at the Seabed 2030 Global Center, hosted at the National Oceanography Centre, UK, with the aim of producing a seamless global terrain model. Outside of Polar regions, the gridded bathymetric data sets supplied by the Regional Centers, as sparse grids, i.e. only grid cells that contain data were populated, were included on to the base grid without any blending. The data sets supplied in the form of complete grids (primarily areas north of 60N and south of 50S) were included using feather blending techniques from GlobalMapper software. The GEBCO_2020 Grid has been developed through the Nippon Foundation-GEBCO Seabed 2030 Project. This is a collaborative project between the Nippon Foundation of Japan and the General Bathymetric Chart of the Oceans (GEBCO). It aims to bring together all available bathymetric data to produce the definitive map of the world ocean floor by 2030 and make it available to all. Funded by the Nippon Foundation, the four Seabed 2030 Regional Centers include the Southern Ocean - hosted at the Alfred Wegener Institute, Germany; South and West Pacific Ocean - hosted at the National Institute of Water and Atmospheric Research, New Zealand; Atlantic and Indian Oceans - hosted at the Lamont Doherty Earth Observatory, Columbia University, USA; Arctic and North Pacific Oceans - hosted at Stockholm University, Sweden and the Center for Coastal and Ocean Mapping at the University of New Hampshire, USA.

Collection of geophysical and oceanographic data from several cruises dedicated to the repeated mapping and monitoring of three UK Marine Protected Areas (MPAs) - Haig Fras, Whittard Canyon and the Darwin Mounds. Data were collected during the following 2018-2020 cruises: JC166/7, DY103, DY108/9, DY120 and DY106. Data collection took place at three of the UK’s MPAs - Haig Fras Marine Conservation Zone (MCZ) in the Celtic Sea, Whittard Canyon submarine complex, which includes The Canyons MCZ, situated off the south west UK continental shelf and Darwin Mounds Special Area of Conservation (SAC), situated in the northern Rockall Trough. An Autonomous Underwater Vehicle (AUV) was used to collect photographic data, sidescan sonar and multibeam bathymetry. Other data included shipboard multibeam bathymetry data; moored ADCP, CTD and sediment trap datasets from repeat mooring deployments; ROV video, pushcores and specimen samples; settling plate experiments; box cores and mega cores; BioCam imagery. The MPAs under investigation had been previously surveyed on cruises JC035 (2009) and JC125 (2015) hence these cruises formed part of the Fixed Point Observations Underpinning Activity. Here repeated observations and surveys of MPAs and their surroundings aim to provide insight into the development and recovery of benthic ecosystems following natural and/or anthropogenic impacts. The data collection was undertaken by scientists at the UK’s National Oceanography Centre (NOC) and formed part of the Natural Environment Research Council (NERC) Climate Linked Atlantic Sector Science (CLASS) Programme (NERC grant reference NE/R015953/1).

This dataset consists of a variety of hydrographic, biological, biogeochemical and meteorological data. Underway automatic sampling followed by flow cytometry was used for assessing mesoscale spatial variability of microorganisms. Coarse-scale (CTD) and fine-scale (PumpCast profiler) vertical distribution of microorganisms was determined, with dominant microbial prokaryotic and eukaryotic groups quantified by flow cytometry. Samples were collected and processed for subsequent molecular identification of flow cytometrically sorted dominant microbes. Abundance of larger microplankton organisms was assessed. Microbial respiration in the twilight zone was studied. Group-specific uptake of bicarbonate, phosphate and different nitrogen compounds was determined and group-specific production and grazing assessed using flow sorting. The ambient turnover rates of phosphate, organic phosphorus and labile dissolved organic matter, e.g. amino acids, was bioassayed. In order to put the microbial community data into context, physical and chemical parameters were measured. A ship mounted Acoustic Doppler Current Profiler (ADCP) was used to collect information about physical, mesoscale spatial context and, when combined with turbulence profiler data, SeaSoar profiler data and data collected using intensive Conductivity, Temperature and Depth (CTD) sampling for dissolved inorganic nutrients, may estimate mesoscale nutrient fluxes into the photic zone. PELAGRA neutral buoyancy sediment traps were used to estimate biogenic sedimentation. Samples were collected for particulate calcite, opal, and Particulate Organic Matter (POM) measurements, together with the isotopic composition of Particulate Organic Nitrogen (PON). Data collection was in the North Atlantic subtropical gyre between 9th August and 15th September 2011 during RRS Discovery cruise D369. The data were collected as part of the United Kingdom (UK) Natural Environment Research Council (NERC) Oceans 2025 programme (Theme 2). D369 was the last of three National Oceanography Centre 'process study' research cruises to be run by the Ocean Biogeochemistry and Ecosystems research group under the NERC Ocean 2025 research programme. The Principal Scientist was Mikhail V Zubkov of National Oceanography Centre, Southampton. Data from this cruise are held at the British Oceanographic Data Centre.

The data set comprises hydrographic data, including salinity, temperature, depth, dissolved oxygen, transmittance and chlorophyll. Chemical and biological measurements of water samples, such as dissolved inorganic nutrients, trace metals (including iron and aluminium), dissolved oxygen, biogenic silica, particulate inorganic/organic carbon and particulate organic nitrogen. Also included are the results of biological experiments focusing on iron and ecosystem grazing pressures. This data set was generated by two research cruises (RRS Discovery cruises D350 and D354) carried out as part of the Irminger Basin Iron Study (IBIS). Data were collected from the Irminger and Iceland Basins on the cruises, which took place between 26/04/2010 and 11/08/2010. Standard cruise measuring techniques, including CTD casts, the ship’s underway system, discrete water sampling and SeaSoar surveys were carried out. In addition, water was collected from an epoxy-coated tow fish and pumped directly into a clean chemistry container using a Teflon pump system through acid washed PVC tubing. Experimental work was performed to measure the biological response to both artificial manipulation of the availability of the micronutrient iron and grazing pressure. Measurement of the uptake rate of various substrates was further performed using a variety of tracer techniques. The study aimed to study the iron biogeochemistry in the high attitude North Atlantic, assess whether community productivity in parts of the North Atlantic is iron limited following the annual spring bloom and determine the factors that lead to this situation. Collectively, the sampling methods adopted as part of IBIS provide a good understanding of the water column structure and the processes taking place within it. The data were collected by scientists at the National Oceanography Centre (NOC) under the supervision of Eric Achterberg. Hydrographic data from the CTDs and underway system (together with associated discrete chemical and biological sample data) are currently held at the data centre. The remaining data described are yet to be supplied.

This dataset comprises hydrographic sections, together with measurements collected by ocean gliders and moored instrumentation deployed during the UK Overturning In the Subpolar North Atlantic Programme (UK-OSNAP). UK-OSNAP is the UK contribution to the International OSNAP Programme. The dataset also includes modelling output informed by the observations. OSNAP observations are focused on two lines: i) OSNAP West, extending from south Labrador to southwest Greenland and ii) OSNAP East from southeast Greenland to Scotland. Data collection commenced June 2014 and is ongoing. UK-OSNAP consists of cruises JR302, PE399, DY053, DY054, two alternating glider deployments, current meter moorings (five at Cape Farewell and three in the Rockall trough) and ADCPs in the Rockall Trough Shelf Edge Current. The model data addresses the Subpolar Gyre circulation and fluxes using data assimilation and theoretical analysis. The datasets assembled as part of UK-OSNAP provide a continuous record of full-depth, trans-basin mass, heat, and freshwater fluxes in the North Atlantic Subpolar Gyre. These, coupled with the associated modelling exercises help improve the understanding of the circulation and fluxes of the North Atlantic Subpolar Gyre. UK-OSNAP, funded by the Natural Environment Research Council (NERC) is led by the National Oceanography Centre (NOC). UK-OSNAP is a partnership between NOC, Scottish Association for Marine Science (SAMS), University of Oxford and the University of Liverpool. It is part of international OSNAP that is led by USA and includes 10 further partner groups in Canada, France, Germany, the Netherlands and China. Investigators: National Oceanography Centre (NOC): Dr Penny Holliday, Dr Sheldon Bacon, Dr Chris Wilson, Neill Mackay. Scottish Association for Marine Science (SAMS): Dr Stuart Cunningham, Prof Mark Inall, Loic Houpert. University of Oxford: Prof David Marshall, Dr Helen Johnson. University of Liverpool: Prof Ric Williams, Dr Vassil Roussenov. The full dataset is still being assembled and currently consists of near real time glider measurements, mooring data and cruise data. NERC have added an extension to UK-OSNAP, until October 2024. This will result in the UK-OSNAP-Decade: 10 years of observing and understanding the overturning circulation in the subpolar North Atlantic (2014-2024).

This dataset consists of measurements of temperature, pressure and depth collected using conductivity-temperature-depth (CTD) casts, chlorophyll, water chemistry and biogenic silica data taken from CTD and underway samples, and underway meteorology, navigation and sea surface hydrography. Data were collected in the Southern Ocean, specifically the Drake Passage, Weddell Sea and Powell Basin, on the RRS James Clark Ross cruises JR255A (20th January to 03rd February 2012) and recovery cruise JR255B (04th February 22nd March 2012) Biogenic silica and chlorophyll samples were collected from the non-toxic underway and CTD Niskin bottles, filtered, dried and processed spectrophotometrically post-cruise. Similarly, water chemistry samples were collected, filtered and dried before post-cruise processing with an elemental analyser. A SeaBird CTD rosette was launched at stations throughout the cruise collecting temperature, pressure and depth values with an attached deep ocean thermometer collecting temperature data which were used to calibrate the CTD data. The underway oceanlogger was running through the duration of the cruises, excepting times for cleaning, entering and leaving port, and while alongside. The data were collected as part of the “Gliders: Excellent New Tools for Observing the Ocean (GENTOO)” project. The objectives of the GENTOO project are: (i) To quantify and understand the possible new source of dense water overflow and its variability; to determine the outflow's potential as an early indicator of Antarctic climate change; to assess the impact of changing dense overflows on the locations and strengths of the surface currents and frontal jets; to provide valuable constraints for climate models that describe how changes in ocean circulation feedback on and regulate climate change in polar latitudes. (ii) To determine the krill biomass distribution and (temporal and spatial) variability to the east of the Antarctic Peninsula and its likely impact on the circumpolar krill ecosystem; to assess the impact of any variations in the location of the frontal jets (from objective i) on the krill biomass distribution; to alleviate a severe regional lack of field data on krill, a key species in the Antarctic food web. To achieve the two objectives, our technological deliverable is a critical evaluation of our ability to measure (a) current velocity from a glider and (b) krill biomass from a glider. The data were collected under NERC lead grant NE/H01439X/1, with child grants NE/H014217/1, NE/H014756/1 and NE/H015078/1. The principal investigators were Prof. Karen Heywood,University of East Anglia, Environmental Sciences, Prof. Gwyn Griffiths, National Oceanography Centre, Science and Technology, Dr. Sophie Fielding, NERC British Antarctic Survey, Science Programmes and Dr. Stuart Bruce Dalziel, University of Cambridge, Applied Maths and Theoretical Physics, respectively. With regard the samples data (Biogenic silica, water chemistry and chlorophyll) it is important to note that these data ARE NOT the property of NERC. They belong to Walker Smith of the Virginia Institute of Marine Science(VIMS) who has supplied them in support of GENTOO. As such, he must be credited for use of the data. The CTD and underway navigation, meteorology and sea surface hydrography data have been received by BODC as raw files from the RRS James Clark Ross, are currently being processed and are available in raw format from BODC enquiries. The SBE-35 Deep Ocean Thermometer and biogenic silica, chlorophyll-a and particulate organic carbon/nitrogen samples data have been received by BODC as raw files from the RRS James Clark Ross, processed and quality controlled using in-house BODC procedures and will be made available online in the near future.

This dataset consists of measurements of underway meteorology, navigation and sea surface hydrography, seismic reflection and refraction, and bathythermograph data collected during a comprehensive survey of the Tonga-Kermadec island arc-deep-sea trench system, undertaken between April and June 2011. Data were collected on RV Sonne cruise SO215 by an integrated marine geophysical experiment that comprised simultaneous seismic reflection (MCS) and wide-angle (WA) refraction, gravity, magnetic, bathymetry and sub-seabed high-resolution imaging of the Louisville Ridge-Tonga-Kermadec Trench collision system. This cruise formed the field component of NERC Discovery Science project "The Louisville Ridge-Tonga Trench collision: Implications for subduction zone dynamics". The key scientific objectives for the cruise were as follows: a)Determine the 'background' crustal and uppermost mantle structure of the subducting plate; b)Determine the crustal and uppermost mantle structure across and along the Louisville Ridge; c)Determine the physical properties of the leading edges of the subducting and over-riding plates; d)Determine the state of isostasy, ridge-related flexure and moat characteristics at the Louisville Ridge, and the mechanical properties of the subducting and over-riding plates; e)Determine the seafloor morphology and collision-related deformation in the Tonga forearc. The Discovery Science project was composed of Standard Grant reference NE/F004273/1 as the lead grant with child grant NE/F005318/1. The lead grant ran from 1 Mar 2011 - 31 Aug 2016 and the child grant ran from 1 Oct 2010 - 30 Sep 2014. Professor Christine Peirce of University of Durham, Department of Earth Sciences was the principal investigator of the lead grant of this project. Prof Anthony Watts of University of Oxford, Earth Science was the principal investigator of the child grant. The bathythermograph data have been received by BODC as raw files from the RV Sonne, processed and quality controlled using in-house BODC procedures and will be made available online soon. The remaining data have been received by BODC as raw files from the RV Sonne and are available on request.