The data in this archive was collected from CEFAS (Or DFR) research surveys.
It broadly cover the European Shelf with some data from the Iberian Abyssal
Plain. Data was 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.