This dataset contains particle flux analyses and current measurements collected from sediment traps and associated moored current meter instrumentation. Four McLane sediment traps were deployed in the Iceland Basin (by the Ocean Weather Station India) in a mesoscale array around 60 degrees N 20 degrees W to sample particle flux time series between November 2006 - July 2007 and August 2007 - June 2008. Sediment traps were deployed with Aanderaa RCM8 current meters 15 m below the traps, recording current speed and direction once an hour. The sediment traps were initially deployed during RRS Discovery cruise D312 and recovered on RRS Discovery cruise D321. For the second deployment period the traps were deployed on RRS Discovery cruise D321 and recovered on RRS Discovery cruise D340. The first sediment traps were prepared for analysis by scientists shortly after recovery. The second deployment samples were stored in the dark at 4 degrees Celsius until 2016 and were subsequently analysed. All sediment trap samples are preserved with formalin and hence should not be affected by long time storage. The samples were analysed for mass flux, particulate organic carbon (POC) and nitrogen (PON) flux, calcium carbonate flux, biogenic silica flux (including dissolved contribution for deployment 2), strontium flux (including Acantharian cyst fractions for deployment 1 and 2 and particulate fractions for deployment 2). The samples from the latter part of deployment 2 are thought to have severely under collected and so those data are flagged. The dataset was produced for the purposes of calculating sediment fluxes in the Iceland Basin and was funded by the Natural Environment Research Council (NERC) - Oceans 2025 Programme (Grant number NE/L002531/1).

The dataset contains physical, biogeochemical and biological data, including measurements of water temperature, salinity, fluorescence, dissolved gases and current velocities; plankton samples from nets and plankton recorders; water samples for analysis of nutrients, phytoplankton, radioactivity and biogeochemical parameters; benthic cores; meteorological time series (pressure, temperature, humidity, wind velocities); atmospheric samples and ocean-atmosphere fluxes; and results from incubation experiments. The data were collected north of the Crozet Plateau in the Southern Ocean/Southwest Indian Ocean on RRS Discovery cruises D285 (3rd November - 10th December 2004) and D286 (13th December 2004 - 21st January 2005). Much of the data collection focussed on a series of Major Stations (called M1 to M10), with measurements being collected at these stations every two or three days. Conductivity-temperature-depth (CTD) casts were undertaken at each station, providing both hydrographic data and water samples from a range of depths. Other work at each Major Station included zooplankton nets, Longhurst-Hardy Plankton Recorder (LHPR) tows, sediment coring and Argo float deployment. In between Major Stations some additional CTD casts were undertaken. The SeaSoar oceanographic undulator provided further hydrographic data, while hull-mounted acoustic Doppler current profilers (ADCPs) provided current velocity data across the survey area. In addition, continuous underway measurements of hydrographic and meteorological parameters and surface water samples were collected along the cruise track. Five moorings were deployed, one of which was recovered at the end of D286. The other four, including sediment traps, current profilers and CTDs were deployed for one year. CROZEX (CROZet circulation, iron fertilization and Export production experiment) is a complex, multidisciplinary project to examine, from surface to sediment, the structure, causes and consequences of a naturally occurring annual phytoplankton bloom that forms. This collaborative project involved researchers in Ireland and the UK, and was administered by the National Oceanography Centre (NOC), Southampton. Data are managed by the British Oceanographic Data Centre. Much of the CROZEX data processing is ongoing and a number of datasets have yet to be submitted to BODC. The data described here are those presently held by BODC, with the exception of the Argo floats (these data are not expected by BODC and should be accessible via the Argo website) and the four year-long mooring deployments (data from these will be submitted to BODC in the future).

The data set comprises a diverse collection of physical, chemical and biological measurements, encompassing over 1000 parameters. There are data from over 1650 conductivity-temperature-depth (CTD)/rosette stations, over 300 core profiles, over 370 sediment trap samples and much, much more. Most of this effort was directed at the region of the east Atlantic margin between La Chapelle Bank and the Goban Spur (between France and Ireland). In addition, there were two secondary areas of interest: the Norwegian Shelf Break just off Tromso and the Iberian Margin, either off Vigo or in the vicinity of the Tagus estuary. Measurements were collected from April 1993 until the end of December 1995 during 55 research cruise legs. Data were collected using a variety of equipment and techniques, including expendable bathythermography (XBTs), CTDs and oceanographic undulators with auxiliary sensors. These hydrographic profiles were accompanied by net hauls, plankton recorder deployments, sediment cores and comprehensive water and air sampling programmes during which a wide variety of chemical and biological parameters were measured. The station data were supplemented by underway measurements of oceanographic and meteorological properties. Results from production and trace metal experiments are also included in the dataset, as are bathymetric data from the British Oceanographic Data Centre (BODC) GEBCO digital Atlas, air-sea flux measurements and data from moored instruments and benthic landers that were deployed for periods from a few weeks to a year. The dataset also includes imagery from satellites, water column and seabed photography, scanning electron micrographs and X-ray photographs. FORTRAN source code for biogeochemical models developed during OMEX I is also included. The aim of the project was to study biogeochemical processes at the shelf break and to quantify the fluxes of material between the shelf and the open ocean. OMEX I involved scientists from 30 institutions in 10 countries. BODC is assembling the data sets collected during OMEX I into its database system and the data are also available on CD-ROM.