The data set comprises hydrographic, biogeochemical and biological data, including measurements of temperature, salinity and attenuance, plus concentrations of parameters such as nutrients, pigments, urea, hydrocarbons, sedimentation flux, sulphur and dissolved carbon. Analyses of bacterial, zooplankton and phytoplankton communities were also undertaken. The oceanographic data were supplemented by measurements of surface meteorological parameters. Data were collected across three repeated sections: one along the Gulf of Oman; a section at 67deg East from 8 to 14.5deg North; and a major section from 8deg North, 67 deg East to the coast of Oman. Other one-off sections were also traversed in the Arabian Sea and Gulf of Oman areas. Measurements were collected during two cruises: one between 27 August and the 4 October 1994 and the other between the 16 November and the 19 December 1994. Sections were covered by underway surface ocean measurements (one minute sampling of multiple parameters providing some 5 million measurements) complemented by a total of 21 CTD/water-bottle stations, 14 of which were repeated. ARABESQUE was organised by the Plymouth Marine Laboratory of NERC's Centre for Coastal and Marine Sciences and involved the University of Wales, Bangor; Queen's University of Belfast; University of East Anglia; University of Edinburgh; University of Newcastle; the Bedford Institute of Oceanography, Canada; the Max Planck Institute for Limnology, Germany and the Sultan Qaboos University, Oman. Data management support for the project was provided by the British Oceanographic Data Centre. All data collected as part of the project were lodged with BODC who had responsibility for assembling, calibrating, quality controlling and fully documenting the data. BODC checked for instrument spikes or malfunction, values beyond the calibration range, unreasonable ratios of chemical constituents and unreasonable deviations from climatological means. Data were assembled into a relational database, complete with supporting documentation and a user manual. The full data set has been published by BODC on CD-ROM complete with user interface.

The data set comprises a diverse collection of physical, chemical and biological measurements, encompassing well over 1000 parameters. There are data from over 1000 conductivity-temperature-depth (CTD)/rosette stations, over 440 core profiles, over 180 sediment trap samples, over 140 net hauls and much, much more. The primary study area was a box extending to the base of the slope from Vigo to Cap Finistere. However, data are included from both further offshore (filament tracking) and from the Portuguese Margin. Measurements were taken from November 1996 to October 1999 during 33 cruise legs, involving research vessels from seven nations. Data were collected using a variety of equipment and techniques, including expendable bathythermographs (XBTs), turbulence probes, CTDs and oceanographic undulators with auxiliary sensors. These hydrographic profiles were accompanied by net hauls, plankton recorder deployments, sediment cores and a comprehensive water 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 phosphate uptake experiments are also included in the dataset, as are bathymetric data from multibeam (swath) surveys, coastal upwelling measurements and data from moored instruments and benthic landers. The dataset also includes imagery from satellites, seabed photography and X-ray photographs of core samples. The aim of the project was study biogeochemical processes at the shelf break and to quantify the fluxes of material between the shelf and the open ocean. The project brought together over 100 scientists from 40 research centres and universities throughout Europe. The British Oceanographic Data Centre (BODC) is assembling the data sets collected during OMEX II into its project database system and the data set is also available on CD-ROM.