2395dbfb4d9d599690f98ca3931e9d19 English dataset Polly Hadžiabdic British Oceanographic Data Centre Head of the BODC Requests Team Joseph Proudman Building 6 Brownlow Street Liverpool Merseyside L3 5DA United Kingdom enquiries@bodc.ac.uk http://www.bodc.ac.uk/ pointOfContact 2018-02-06T15:16:39 MEDIN Discovery Metadata Standard Version 2.3.8 urn:ogc:def:crs:EPSG::4326 OGP Oceanographic data from the Propagation Channel Simulator (PROSIM) Clyde Sea experiment British Oceanographic Data Centre record 1048PROSIM 2017-10-03 publication 2010-10-01 creation 2011-01-26 revision EDMED4279 http://www.bodc.ac.uk/ The data set comprises measurements of water temperature, salinity, current velocities and sound velocity, and sediment characteristics. The data were collected in the Clyde Sea in July and August 1997. The bulk of the measurements were made at the acoustic transmission point Tx1 (55 31.6N, 4 49.7W), and at receiving points SW of Tx1 up to 20 km away. In addition a SW-NE section (55 13.5N, 5 9.4W to 55 35.0N, 4 46.3W) was sampled at the beginning and end of the experiment, and a W-E section (5 3.0W to 4 52.7W at 55 31.6N) was run three times during the experiment. The data were collected by the research vessels Prince Madog and Calanus. Throughout the experiment the Prince Madog was used to deploy the acoustic transmission equipment, and as the main oceanographic vessel. The Calanus acted as the receiving ship, and also collected conductivity-temperature-depth (CTD) profiles. Overall, 199 CTD casts, 71 hours of temperature time series data, 150 hours of acoustic Doppler current profiler (ADCP) data, 70 hours of RoxAnn (sidescan sonar), position and water depth data, and three sediment sound speed profiles were collected. Two CTDs were used onboard the Prince Madog: a Seabird SBE-19 and a Neil Brown Mk. III. A Neil Brown SmartCTD was used on the Calanus. Several casts were made onboard the Madog with both CTDs attached to the same frame for intercalibration purposes. At the bottom of each cast with the Neil Brown Mk. III CTD two SIS digital reversing thermometers were triggered and a seawater sample collected, which was later analysed in the laboratory for salinity. Temperature and salinity data from the Madog CTDs were calibrated using these values. No seawater samples were collected by the Calanus. Data from all CTDs were despiked and spurious density inversions were removed. The majority of the CTD casts were repeat casts at either the acoustic transmission or reception point, the object being to monitor the high frequency variability of the water column, and allow model predictions of the acoustic signal characteristics to be tested against observed signal variations. Whilst the Prince Madog was on station at Tx1 four internally recording temperature sensors were deployed at fixed depths. During some overnight runs a single temperature/depth sensor was also deployed; during transmission experiments this sensor was attached to the acoustic source. The ADCP onboard the Madog was used to record vertical current profiles for most of the experiment. A RoxAnn system onboard the Prince Madog was used during part of the experiment to log ship position, water depth, and the bottom roughness and hardness indices E1 and E2. Three bottom sediment cores were collected on 5/8/97 with a hydroplastic (gravity) corer. Two metre core barrels with an internal diameter of about 8cm were used. The cores each contained between 1m and 1.5m of sediment, and were analysed for sound speed at the University of Wales, Bangor after the cruise. The cores were taken at Tx1 (55.527N, 4.832W), 10 km (55.441N, 4.843W), and 20 km (55.371N, 4.880W) along the primary acoustic track. The precision of the sound speed measurements is +/- 10 m/s. The PROSIM Clyde Sea experiment was primarily an acoustic transmission experiment designed to study shallow water acoustic propagation. The oceanographic data were collected to provide information on the mean and time-varying characteristics of the water column for use in acoustic modelling. PROSIM was undertaken by the Unit for Coastal and Estuarine Studies, a self-funded research unit attached to the School of Ocean Sciences, University of Wales, Bangor. The unit specialises in physical oceanography and ocean modelling. The data are stored at the British Oceanographic Data Centre (BODC). Unknown University of Wales, School of Ocean Sciences Unknown School of Ocean Sciences, University of Wales Bangor, Menai Bridge, Anglesey, Menai Bridge Anglesey LL59 5AB United Kingdom inapplicable http://www.sos.bangor.ac.uk/ originator British Oceanographic Data Centre Director Joseph Proudman Building 6 Brownlow Street Liverpool Merseyside L3 5DA United Kingdom enquiries@bodc.ac.uk http://www.bodc.ac.uk/ custodian asNeeded Sediment acoustics Sound velocity and travel time in the water column Vertical velocity of the water column (currents) Salinity of the water column Temperature of the water column Horizontal velocity of the water column (currents) SeaDataNet PDV 2018-01-12 revision unknown Vertical Coverages 2013-02-06 revision Natural Environment Research Council Designated Data Centres Marine Environmental Data and Information Network MEDIN metadata record availability 2012-01-11 revision Geology Oceanographic geographical features INSPIRE themes 2009-07-31 revision Usage restrictions are specified in the terms of the licence otherRestrictions Data are freely available to all following agreement to the terms and conditions of a Data Licence English oceans -6.00 -4.00 55.00 56.00 1997 1997 British Oceanographic Data Centre Director Joseph Proudman Building 6 Brownlow Street Liverpool Merseyside L3 5DA United Kingdom enquiries@bodc.ac.uk http://www.bodc.ac.uk/ distributor dataset Instrument(s) used to collect data: current profilers; sidescan sonars; unconsolidated sediment corers; CTD; water temperature sensor.