The Porcupine Abyssal Plain (PAP) Observatory is a sustained, multidisciplinary observatory. Key time-series datasets include measurements of sea temperature, air temperature, air pressure, waves, wind, CO2, salinity, Megafauna (Species diversity, abundance and biomass), geochemistry, humidity, chlorophyll, nitrate, PAR and currents. The PAP observatory is situated in the Northeast Atlantic away from the continental slope and mid Atlantic ridge (49N,16.5W, depth 4800m). Since 1989, this environmental study site in the Northeast Atlantic has become a major focus for international and interdisciplinary scientific research and monitoring including water column biogeochemistry, physics and benthic biology. Since 2002, a mooring has been in place with sensors taking a diverse set of biogeochemical and physical measurements of the upper 1000m of the water column. Some of these data are transmitted in near real-time via satellite. A diverse range of Essential Climate variables are measured and sampled at the PAP site from the atmosphere and surface ocean to the seafloor. The instruments used include CTD + Backscatter; ADCP (2 way, re-programmable for water profiling as well as burst sampling), Seismometer (2 way, retrieval of selected time period - 1 Minute - in the past e.g. seismic event), Bottom Pressure Sensor, Sediment trap (2 way, re-programmable for change sampling interval), Boxcores, Mega- and Multicores, Optode, Digital Camera and Stand-alone hydrophone. Seafloor sampling includes trawling, coring, towed camera systems from a research ship and time-lapse photography. Since 2002 many of the upper ocean measurements (0-1000m) have been transmitted in near real-time. There is a growing need for ever more accurate climatic models to predict future climate change and the impact this will have on human settlement, the insurance industry, fisheries, agriculture and nature at large. Long term observations at fixed points in the open oceans are essential to provide high quality and high resolution data to increase our knowledge of how our oceans function, how they are changing and how this may impact on the climate. The observatory is coordinated by the National Oceanography Centre. In 2010, a collaboration between NERC and UK Met Office has led to the first atmospheric measurements at the site.

The dataset comprises 5 hydrographic data profiles, collected by a conductivity-temperature-depth (CTD) sensor package, from across the North East Atlantic Ocean (limit 40W) area specifically along the south west coast of Western Sahara, during October of 2006. A complete list of all data parameters are described by the SeaDataNet Parameter Discovery Vocabulary (PDV) keywords assigned in this metadata record. The data were collected by the National Oceanography Centre, Southampton as part of the Rapid Climate Change Programme.

The dataset comprises 50 hydrographic data profiles, collected by a conductivity-temperature-depth (CTD) sensor package, from across the North East Atlantic Ocean (limit 40W) area specifically around the Mid-Atlantic Ridge, during July and August 2007. A complete list of all data parameters are described by the SeaDataNet Parameter Discovery Vocabulary (PDV) keywords assigned in this metadata record. The data were collected by the National Oceanography Centre, Southampton as part of the ECOsystems of the Mid Atlantic Ridge (ECOMAR) project.

The dataset comprises 117 hydrographic data profiles, collected by a conductivity-temperature-depth (CTD) sensor package, from across the South Atlantic Ocean area specifically a complete section from continent to continent from South America to Africa, during March and April of 2009. A complete list of all data parameters are described by the SeaDataNet Parameter Discovery Vocabulary (PDV) keywords assigned in this metadata record. The data were collected by the National Oceanography Centre, Southampton.

The Rapid Climate Change (RAPID) data set comprises a diverse collection of oceanographic and benthic observations, including profiles of temperature, salinity, dissolved gases and currents. The dataset also includes discrete measurements of plankton, stable isotopes, dissolved metals, chlorofluorocarbons (CFCs) and nutrients in the water column, sediment grain size parameters and geochemistry, and atmospheric concentrations of inorganic halogens. The RAPID data were collected from numerous locations in the North Atlantic, North Sea, Greenland and Europe via over 30 cruises between 2004 and 2008. Many of the oceanographic data resulted from an extensive mooring array in the North Atlantic devoted to monitoring the Atlantic overturning circulation. These mooring arrays are continuing to return data in the follow-on programmes, Rapid Climate Change - Will the Atlantic Thermohaline Circulation Halt? (RAPID-WATCH, 2008-2015) and RAPID - Atlantic Meridional Overturning Circulation (RAPID-AMOC, 2015 onwards) which will result in a decadal time series spanning the North Atlantic. RAPID, RAPID-WATCH and RAPID-AMOC aim to investigate and understand the causes of rapid climate change, with a primary (but not exclusive) focus on the role of the Atlantic Ocean thermohaline circulation. A Rapid Climate Change project office has been established at the National Oceanography Centre, Southampton. The cruise and mooring data are managed by the British Oceanographic Data Centre and are supplemented by atmospheric model output held at the British Atmospheric Data Centre (BADC).

The dataset comprises concentration of gas hydrates beneath the seabed, in the water column and, atmosphere along with the topography of the sea floor. Data were collected in the Arctic Ocean off the NorthWestern coast of Svalbard across the continental margin between 78 and 80 North and 4 and 11 East. The data were collected during cruise JR211 which, over two legs, took place between 23rd August 2008 and 24th September 2008. Geophysical and geological techniques were used to detect methane hydrate beneath the seafloor and to investigate features trough which methane escapes to the seafloor. The seabed was imaged and mapped using a multibeam sonar (Simrad EM120), an echosounder (Simrad EK60), TOBI deep-towed sidescan sonar (30 kHz), widescan sidescan sonar (100 and 350 kHz). The sedimentary layers and geological structures beneath the seabed were imaged with the 7 kHz profiler in TOBI, a TOPAS sub-bottom acoustic profiler and multichannel seismic reflaction (96 channels with 6.25 m group spacing) using two air guns in true GI mode 45/105 cu.in. More accurate information on seismic velocity was obtained by deploying ocean-bottom seismometers on the seabed which contained 3 Sercel L-28 4.5 Hz geophones and a High Tech HTI-90-U hydrophone. Sediment samples were obtained using a piston corer, a gravity corer and, a box corer. Water chemistry was measured from discrete samples taken from bottles attached to the conductivity-temperature-depth (CTD) sensor package and continuously from the ship's seawater supply. Methane concentration was measured on-board using a headspace technique. Air samples were collected at 12 hour intervals. Sampling occurred on the Navigation Bridge deck and the side of the ship upwind of the ships emissions was chosen each time. Additional samples were also collected close to the ship's funnel, to check for contamination, and from the gas released by the cores when in an inert atmosphere (N2). Analysis of methane mixing ratio is performed by Gas Chromatography - Flame Ionisation Detector (GC-FID) and the stable carbon isotopic composition of methane is analysed using a continuous flow Gas Chromatography - Isotope Ratio Mass Spectrometry (GC-IRMS) system. Almost half of the Earth's carbon is stored in gas hydrates and related shallow gas deposits. Numerical models predict that this reservoir is highly mobile and that escaping gas has a significant potential to accelerate climate change releasing as much as 2000 Gt of methane over a short period of time. As methane is a potent greenhouse gas it would course further global warming. Arctic gas hydrates are most vulnerable to future climate change because (1) it is predicted that temperatures will increase faster in the Arctic than in low latitudes (2) the intercept of the gas hydrate stability zone with the seabed is within the reach of fast warming surface waters and (3) the water column above the vulnerable zone of gas hydrates is smaller than in warmer oceans facilitating more efficient transport of greenhouse gases to the atmosphere. This information will allow a detailed assessment of the mobility of Arctic gas hydrates and it will significantly decrease the uncertainties involved in climate modelling. The data were collected by the National Oceanographic Centre, Southampton with Professor Tim Minshull as the principal scientist on-board.

Seawater samples were collected from a series of ships of opportunity transiting between the UK and the Caribbean. Crossings occured almost monthly between May 2002 and October 2017. Roughly 90-100 samples were collected for each return journey from the ships' underway system and were frozen immediately for subsequent laboratory analysis. Nitrate, silicate, and phosphate levels were measured from these seawater samples. This work was funded by 5 different projects over the years - The Carbon variability studies by ships of opportunity (2000-2003), CARBOOCEAN FP6 (2001-2009), Carbochange (2011-2015), FixO3 (2013-2016), and NERC Greenhouse Gas most recently.

This dataset consists of 20 CTD cast profiles from 20 stations in the Whittard Canyon and Haig Fras marine conservation zones, as part of the CodeMAP (Complex Deep-sea Environments: Mapping habitat heterogeneity As Proxy for biodiversity) project. These data were collected aboard the RRS James Cook cruise JC125 (Chief Scientist Veerle Huvenne), which departed and returned to Southampton from 09 August 2015 to 12 September 2015. The cruise was conducted to carry out habitat mapping work in the Whittard Canyon and Haig Fras to obtain a better insight in the biodiversity patterns, benthic habitat distributions and sediment transportation processes of submarine canyons. The CTD profile data collected supports data from marine geology, ecology, remote sensing and underwater vehicle technology to establish an integrated, statistically robust, and fully 3D methodology to map complex deep-sea habitats. Parameters measured from the CTD profiles include: pressure, depth, temperature, practical salinity, dissolved oxygen, chlorophyll-a fluorescence, transmittance, attenuance and turbidity. Data were collected using a ship deployed stainless steel CTD frame mounted with the following equipment: Sea-Bird 911plus CTD System, Digiquartz pressure sensor, Sea-Bird 3plus premium temperature sensor, Sea-Bird 4C conductivity sensor, Sea-Bird 43 dissolved oxygen sensor, WET Labs ECO BB(RT)D backscattering sensor, Chelsea Technologies Group Aquatracka III fluorometer, Chelsea Technologies Group Alphatracka II transmissometer (25 cm path length). The CTD data were received by the British Oceanographic Data Centre (BODC) having been binned into 2 m depth profiles for the downcast. The data have been processed and quality controlled using in-house BODC procedures and are available to download from the BODC website. Funding was provided by the European Research Council to CodeMAP (Grant No 258482).

This dataset consists of coccolithophore abundances in the North Atlantic that were collected from 37 CTD casts during three RRS Discovery cruises (D350, D351, D354) in the spring and summer of 2010. Water samples (0.2-1 L) were collected from CTD casts and filtered through cellulose nitrate (0.8 µm) and polycarbonate (0.45 µm or 0.8 µm) filters, rinsed with trace ammonium solution, oven dried (30-40 °C, 6-12 h) and stored in Millipore PetriSlides. The filters were examined using a Leo 1450VP scanning electron microscope, with coccolithophores identified following Young et al. (2003), and enumerated from 225 fields of view (Daniels et al., 2012). The detection limit was estimated to be 0.2-1.1 cells mL-1. The samples were collected to investigate coccolithophore community dynamics in the North Atlantic as part of the Irminger Basin Iron Study (IBIS)(D350, D354), Extended Ellett Line (EEL)(D351) and a NERC Fellowship. Samples were collected on D350 by Martine Couapel, on D351 by Stuart Painter and on D354 by Alex Poulton and Mike Lucas. In the lab, samples were prepared and processed by Chris Daniels, Elena Maher and Jonathan Hurst, and were analysed for coccolithophore abundances by Chris Daniels and Jeremy Mirza. The data are held at the British Oceanographic Data Centre (BODC). Daniels, C. J., Tyrrell, T., Poulton, A. J., and Pettit, L.: The influence of lithogenic material on particulate inorganic carbon measurements of coccolithophores in the Bay of Biscay, Limnol. Oceanogr., 57, 145-153, doi:10.4319/lo.2012.57.1.0145, 2012. Young, J. R., Geisen, M., Cros, L., Kleijne, A., Sprengel, C., Probert, I., and Ostergaard, J.: A guide to extant coccolithophore taxonomy, J. Nannoplankt. Res. Special Issue, 1, 1-132, 2003.

This dataset contains hydrographic profiles (temperature, salinity, oxygen, fluorometer, transmissometer, irradiance) and along track measurements (bathymetry, surface meteorology, sea surface hydrography), with discrete measurements including water chemistry (organic and inorganic nutrients, particulate organic carbon and nitrogen, dissolved gases, trace metals) collected from a hydrographic section in the North Atlantic Ocean. This hydrographic section, designated A05 by the World Ocean Circulation Experiment (WOCE), runs along a nominal latitude of 24.5N between Florida and either Spain, North Africa, Portugal or the Canary Islands. Four UK cruises (D279, D346, DY040 and JC191) have contributed to this dataset to date using CTD casts, vessel-mounted and lowered ADCPs, bottle sampling and meteorological measuring systems to collect data. The measurements were collected as one of the UK's contributions to the Global Ocean Ship-based Hydrographic Investigations Program (GO-SHIP) and with the aim of contributing to the study of decadal variability of the present ocean circulation and meridional transport of heat, freshwater and biogeochemistry, as part of the Climate Linked Atlantic Sector Science (CLASS) project. The work was led by teams from the National Oceanography Centre at Southampton. Data from the section are held at the British Oceanographic Data Centre (BODC).