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.

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 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.

This dataset consists of measurements of underway meteorology, navigation and sea surface hydrography. The data were collected on RRS Discovery cruise DY051 through the Goban Spur and Rockall Trough areas of the North East Atlantic. The cruise spanned the 13th of May to the 3rd of June 2016. Navigation data were collected using an Applanix POSMV system and meteorology and sea surface hydrography were collected using the NMF Surfmet system. Both systems were run through the duration of the cruise, excepting times for cleaning, entering and leaving port, and while alongside. The data were collected as part of the MAC-EXP: Development of a pressurised sampling, experimentation and cultivation system for deep-sea sediments project. The project aims to develop a flexible, cost-effective alternative to in situ experimentation: a pressure-coring, experimentation and cultivation system that enables studies of deep-sea prokaryote biodiversity and ecosystem functioning, under ambient or manipulated pressure, temperature and oxygen conditions from any medium sized ocean going research ship with coring capability. This Multiple-Autoclave-Coring and Experimentation system (MAC-EXP) will aim to provide the possibility to systematically test the influence of environmental parameters, such as pressure, oxygen availability or pH on deep-sea organisms and their biochemistry, as well as on rates and pathways of biogeochemical and geomicrobial processes. The system will also aim to allow pioneering work in the field of marine biodiscovery: secondary metabolites from marine microorganisms are a rich source of chemical diversity and several marine-microbe derived compounds are now in clinical trials. Funding was provided by NERC Standard grants NE/I023465/1 (lead) and NE/I024232/1. The lead grant covered 01 February 2013 to 31 December 2016 and the child grant covered 01 April 2012 to 31 March 2015. Professor Ursula Witte of University of Aberdeen, Institute of Biological and Environmental Sciences was the principal investigator for the lead grant. Professor Ronald J Parkes of Cardiff University School of Earth and Ocean Sciences was the principal investigator for the child grant. The underway navigation, meteorology and sea surface hydrography data have been received by BODC as raw files from the RRS Discovery, processed and quality controlled using in-house BODC procedures and will be made available online in the near future.

For around a decade, southern elephant seals (mirounga leonina) have been used to collect hydrographic (temperature & salinity) profiles in the Southern Ocean. CTD-SRDLs (Conductivity Temperature Depth –Satellite Relayed Data Loggers) attached to seals' heads in Antarctic and sub-Antarctic locations measure water property profiles during dives and transmit data using the ARGOS (Advanced Research & Global Observation Satellite) network (Fedak 2013). CTD-SRDLs are built by the Sea Mammal Research Unit (SMRU, University of St Andrews, UK); they include miniaturised CTD units made by Valeport Ltd. When seals are foraging at sea 2.5 profiles can be obtained daily, on average. Profiles average 500m depth, but can be 2000m in extreme cases (Boehme et al. 2009, Roquet et al. 2011). Deployment efforts have been very intensive in the Southern Indian Ocean, with biannual campaigns in the Kerguelen Islands since 2004 and many deployments in Davis and Casey Antarctic stations (Roquet et al., 2013) more recently. 207 CTD-SRDL tags have been deployed there, giving about 75,000 hydrographic profiles in the Kerguelen Plateau area. About two thirds of the dataset was obtained between 2011 & 2013 as a consequence of intensive Australian Antarctic station deployments. There is also regular data since 2004 from French and Franco-Australian Kerguelen Island deployments. Although not included here, many CTD-SRDL tags deployed in the Kerguelen Islands included a fluorimeter. Fluorescence profiles can be used as a proxy for chlorophyll content (Guinet et al. 2013, Blain et al. 2013). Seal-derived hydrographic data have been used successfully to improve understanding of elephant seal foraging strategies and their success (Biuw et al., 2007, Bailleul, 2007). They provide detailed hydrographic observations in places and seasons with virtually no other data sources (Roquet et al. 2009, Ohshima et al. 2013, Roquet et al. 2013). Hydrographic data available in this dataset were edited using an Argo-inspired procedure and then visually. Each CTD-SRDL dataset was adjusted using several delayed-mode techniques, including a temperature offset correction and a linear-in-pressure salinity correction - described in Roquet et al. (2011). Adjusted hydrographic data have estimated accuracies of about +/-0.03oC and +/-0.05 psu (practical salinity unit). The salinity accuracy depends largely on the distribution of CTD data for any given CTD-SRDL, which decides the quality of adjustment parameters. Adjustments are best when hydrographic profiles are available in the region between the Southern Antarctic Circumpolar Current Front and the Antarctic divergence (55oS-62oS latitude range in the Southern Indian Ocean). Several institutes provided funding for the associated programs and the logistics necessary for the fieldwork. The observatory MEMO (Mammifères Echantillonneurs du Milieu Marin), funded by CNRS institutes (INSU and INEE), carried out the French contribution to the study. The project received financial and logistical support from CNES (TOSCA program), the Institut Paul-Emile Victor (IPEV), the Total Foundation and ANR. MEMO is associated with the Coriolis centre, part of the SOERE consortium CTD02 (Coriolis-temps différé Observations Océaniques, PI: G. Reverdin), which distributes real-time and delayed-mode products. The Australian contribution came from the Australian Animal Tracking and Monitoring System, an Integrated Marine Observing System (IMOS) facility. The work was also supported by the Australian Government's Cooperative Research Centres Programme via the Antarctic Climate & Ecosystem Cooperative Research Centre. The University of Tasmania and Macquarie University's Animal Ethics Committees approved the animal handling. Both tagging programs are part of the MEOP (Marine Mammals Exploring the Oceans Pole to Pole) international consortium - an International Polar Year (IPY) project.

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.

This collection comprises physical measurements of the water column and surface waters, together with supporting discrete chemical and biological datasets. The data were obtained from the Irish Sea and in the sea off western Scotland over 4 periods: 17 and 23 August 2011 and 06 - 07 March 2012, all collected on Seiont IV cruises and 15 - 22 June 2012 obtained using the RV Prince Madog. These datasets and their collection methods are as follows: 1) LISST particle size data - A LISST 100X type C laser diffraction instrument was lowered in a frame from the ship and the depth-averaged volumes of particles in 32 size classes in a water column from the surface to a depth of 10 m (or the bottom, where shallower) were measured. 2) CTD profiles of conductivity, temperature, sigma-theta and salinity. At each station, a CTD with attached rosette was lowered, with data measurements taken. 3) SPM, mineral SPM, chlorophyll and CDOM water sample data. At each station a surface water sample was collected either in a bucket or in a rosette sampler on the CTD and triplicate sub-samples were filtered and subsequently dried and weighed, baked (at 500°C for 3 hours to remove organic material) and weighed again. 4) CDOM discrete samples taken from CTD and underway. Surface water samples collected at each station were filtered through 0.2 μm filters and the spectral variation of the absorption coefficient of the dissolved material in the filtrate was measured in a 10 cm cell in a Shimadzu 1600 dual-beam spectrophotometer, using distilled water as a reference.. 5) Water column inherent optical property profiles. Measurements of beam attenuation were made using a Sea Tech T1000 transmissometer (20cm pathlength) fixed to the CTD on the RV Prince Madog. At some stations, vertical profiles of downwelling irradiance and upwelling radiance were made with a PRR radiometer. These cruises formed the fieldwork component of the NERC-funded project “Measurement of the abundance and optical significance of sub-micron sized particles in the ocean”. The project aimed to use different magnifications and commercially available in-situ particle sizing instruments to create a package of instruments for measuring the undisturbed particle size distributions from 0.2 μm to 1 mm. This package will first be used in a turbulence tank to 'film' the flocculation process. The insight this gives will be used to construct new theoretical models of the particle size distribution. Because the camera also measures the shape of the particles, differences between observed and calculated optical properties can be compared, for the first time, to particle shape. Finally, the complete dataset will be collated to determine what size particles, under what conditions, are primarily responsible for the signals seen in visible band satellite images of the oceans. The NERC-funded project was held under lead grant reference NE/H022090/1 with child grants NE/H020853/1 and NE/H021493/1. The lead grant was held at Bangor University, School of Ocean Sciences by Professor David Bowers and ran from 01 April 2011 to 31 March 2014. Grant NE/H020853/1 was held at the University of Plymouth, School of Marine Science and Engineering by Dr. William Alexander Nimmo Smith and ran from 01 October 2010 to 30 September 2013. Finally, grant NE/H021493/1 was held at the University of Strathclyde Physics Department by Dr. David McKee and ran from 01 April 2011 to 31 March 2014. All data have been received by BODC as raw files from the RV Prince Madog and Seiont IV, processed and quality controlled using in-house BODC procedures.

This dataset consists of a variety of hydrographic, biogeochemical and meteorological data. Hydrographic profiles, towed and underway measurements and point sources provided information on free-fall turbulence data, current velocities and acoustic backscatter, water column structure including temperature and salinity, the underwater light field, fluorescence and dissolved oxygen. A comprehensive biogeochemical water sampling programme provided details on nutrients, primary productivity, dissolved organic matter and phytoplankton pigments. Biological samples such as zooplankton were obtained from the water column using nets, and from the sea-bed using grabs. Bathymetry and meteorological parameters were measured across the study area. A dye release experiment was also carried out. Data collection was undertaken in the Celtic Sea. The data were collected during the period 02 - 27 July 2008 during RRS James Cook cruise JC025. Measurements were taken using a variety of instrumentation, including conductivity-temperature-depth (CTD) profilers with attached auxiliary sensors, bathymetric echosounders, water bottle samplers, nets, acoustic Doppler current profilers (ADCPs), remote access water samplers, towed undulators, free-fall turbulence profilers, temperature loggers, fluorometers, grabs and ship flow-through and meteorological packages. The data have been collected as part of the United Kingdom (UK) Natural Environment Research Council (NERC) Oceans 2025 programme (Work Package 3.2) to provide information on vertical mixing processes at the thermocline. This will help improve modelling of these processes and is an expansion of work carried out during a previous National Oceanography Centre Liverpool (NOCL) project ‘Physical-Biological Control of New Production within the Seasonal Thermocline’. The cruise was undertaken jointly by NOCL, the Scottish Association for Marine Sciences (SAMS), the University of Aberdeen, the University of Strathclyde, Napier University and the Joint Nature Conservation Committee (JNCC). The Principal Scientist during the research cruise was Professor Jonathan Sharples of NOCL, who is also the Principal Investigator of Work Package 3.2. CTD data, towed undulator data, temperature logger data, nutrient data, ADCP data, dye tracking data, zooplankton data, primary productivity data and ship underway monitoring system data from this cruise are held at the British Oceanographic Data Centre. Other data have not yet been supplied.

This dataset describes an evaluation project using ocean glider data collected in the Celtic Sea, funded by the United Kingdom Integrated Marine Observing Network (UK-IMON) initiative. The data measured form a three dimensional trajectory through the water column covering a transect from just North West of the Scilly Isles, to the South west in the Celtic Sea. The date span for the data is 12 September 2013 to mid-October 2013 (expected). Deployment occurred off the RV Cefas Endeavour on 12th September and it is expected that the gliders will be recovered in Mid October. The project includes 2 ocean gliders, both equipped with a CTD and triplet optical phytoplankton fluorescence, backscatter and coloured dissolved organic matter sensor. There is also an echo sounder (on one glider) and Sea Mammal Research Unit (SMRU) Passive Acoustic Monitor (PAM) (cetacean monitoring) on the other glider. The goal of the evaluation project is to study tidal mixing and to contribute to oceanographic sensor development. The organisations contributing to the dataset are the UK National Oceanography Centre (NOC), the Centre for Environment, Fisheries & Aquaculture Science (CEFAS) and the Sea Mammal Research Unit (SMRU). The data are held by BODC as an archive of the real time data stream as transmitted by the glider. The delayed mode full resolution (downloaded on platform recovery) and delayed mode quality controlled data are expected in due course.

The dataset comprises scanned images of historical analogue charts and data ledgers from eight tide gauge sites around the UK. The sites include: Sheerness, Belfast, and several sites around Liverpool managed by the Mersey Docks and Harbour Company namely, Eastham, Gladstone, Hilbre, Princes Pier, Tranmere and Waterloo. The Sheerness ledger data represents some of the earliest records of sea level data in the UK and cover the periods - January 1870 to December 1881, July 1882 to October 1894 and December 1929 to April 1941. Data availability for the other sites are: Belfast analogue charts - 27 November 1901 to 24 May 1902; Princes Pier ledgers: - 1941 to 1950, 1951 to 1960 and 1961 to 1970; Eastham, Gladstone, Hilbre, Princes Pier, Tranmere and Waterloo ledgers: - 1982 to 1988. The data recorded in some of the ledgers also describe meteorological measurements for example, air pressure, air temperature, wind speed and direction, and precipitation and evaporation. Funding to rescue these historical sea level data came from the Marine Environmental Data and Information Network (MEDIN) and the British Oceanographic Data Centre (BODC).These images have now been added to the National Oceanographic Database and are freely available to registered users (subject to licence agreement).