RV CIROLANA 01/1991 Low Resolution Conductivity-Temperature-Depth (CTD) Data dataset https://portal.medin.org.uk/portal/start.php?tpc=009_CEFAS79ee3407-6490-4961-a207-d58c8e65618d The data held in this archive were collected from Cefas (or its predecessor the Directorate of Fisheries Research) research cruises. They broadly cover the European Shelf with some data from the Iberian Abyssal Plain. Data were collected using the lowered CTD rosette system which is used when the vessel is stationary. Usually bottles were fired at particular depths and samples taken for calibration. In early years only a limited set of parameters were collected. Notably Pressure (Depth), Temperature and Conductivity (CTD). From Conductivity Salinity can be calculated using the UNESCO 1978,1983 formulations . In subsequent years more sensors have been added, notably fluorometers, Optical back scatter or transmissometers and Light (PAR, photo synthetically available radiation). The exact configuration varies between cruises and this is reflected in the data format of the output files. Data was collected from research vessels on station, a profile from the surface to near the sea bed is undertaken. The down cast data should be a clean profile. Water bottles for sample collection and calibration are fired on the up cast. 20130515 20130227