CTD data are obtained during the annual CCGS Amundsen scientific expedition.

A large number of CTD rosette casts are performed every year. The rosette has twelve sampling water bottles and several instruments attached to its frame to collect water samples and records physical and chemical data (temperature, conductivity, pressure, fluorescence, light transmission, nitrate, photosynthesis) with sensors. The water samples are distributed to the scientific teams for in-situ analysis. In-situ data belong to and are under the responsibility of the leading scientists while physical and chemical data from the sensors are part of the Amundsen core data collection.

Data typically measured each year and provided in this archive are as follows: temperature, conductivity and pressure (with a Sea-Bird SBE-9plus), dissolved oxygen (Sea-Bird SBE-43), fluorescence (Seapoint chlorophyll fluorometer), CDOM (Wetlabs FL(RT)D), nitrate concentration (Satlantic MBARI-ISUS 5T), transmittance (Wetlabs C-Star transmissometer), light intensity (PAR; LI-COR Biosciences) and surface light intensity (sPAR; LI-COR Biosciences).

Quality control procedures are applied to the data which are available under these formats: .int (one cast by file), .odv, .kml, .btl and .odf (on demand).