CTD profiles (depth, pressure, temperature, salinity, potential temperature, density, fluorescence, transmissance, downwelling PAR, dissolved oxygen concentration) binned to 0.5 m and 0.25 m at sites L4 and E1 in the Western English Channel between January 2002 and December 2014.

This dataset consists of CTD profiles carried out by Plymouth Marine Laboratory (PML) in the Western English Channel from January 2002 to December 2014. These data were collected as part of the Western Channel Observatory, a programme run at PML that has expanded from the L4 plankton time-series started in 1988 at site L4 (50.25 N, 4.22 W) to include site E1 (50.033 N, 4.367 W). The CTD profiles provide a background to the changing properties of the water column at these sites, which are concurrently sampled for a wide range of optical, biological and chemical parameters. Sampling was carried out weekly at site L4 and monthly at site E1 subject to appropriate weather conditions. Salinity, temperature, depth and fluorescence measurements were available throughout the period sampled. Values for pressure, density (sigma-theta), potential temperature and oxygen saturation were derived by BODC. Ancillary sensors that measured transmissance, downwelling PAR and dissolved oxygen concentration were added to the CTD rig during the period and these data were included in the most recent profiles. Sensors deployed on the rig to collect the data were a Sea-Bird SBE19+ SEACAT profiler CTD, Chelsea Technologies MiniTracka II fluorometer, Wetlabs C-star transmissometer (25 cm pathlength red light), Chelsea Technologies PAR sensor and a Sea-Bird SBE43+ dissolved oxygen sensor. Profiles for the period January 2002 to January 2009 were binned to 0.5 m and those from January 2009 to December 2014 were binned to 0.25 m. N.B. These data are a snapshot of profiles and associated documentation for sites and period stated held within the National Oceanographic Database as at the Dataset Publication Date.