Initial CTD data processing used the Sea-Bird data processing software package with input of the raw data file (*.hex) and associated configuration file (*.con) for each cast. Processing steps are described in the file “ctd_process.txt” that accompanies the data files. For bin-averaging, scans acquired during the initial surface “soak” period prior to profiling were removed and only the downcast was processed using 1-m bins for station depths < 100 m and 2-m bins for station depths > 100 m. The bin-averaged data was output in ASCII file format (*b.cnv). Parameter names and units for the output data files are listed above (by column).
Factory calibration factors for CTD package sensors were applied to calculate conductivity, pressure, and temperature (see “ctd_con_report.txt”). Depth was calculated from pressure using the “seawater” setting in the Sea-Bird software and density was calculated by the EOS80 equation of state for seawater (Fofonoff and Millard, 1983). Oxygen (kg/m3, % saturation), optical backscatter (1/m) and PAR (as quantum scalar irradiance, micro-mole photons / m2 s1) were calculated using the manufacturer-supplied calibration factors and algorithms included in the Sea-Bird data processing package. Chlorophyll fluorescence and CDOM fluorescence are reported here as the raw voltages (0-5 volts total signal range).
BCO-DMO Processing:
- added conventional header with dataset name, PI name, version date, reference information, replacing ctd header
- renamed some parameters to BCO-DMO standard
- created toplevel file
- added ctd metadata columns to cast data: cruise_id, cast, year, mon, day_gmt, time_gmt, lat_deg, lat_min, lon_deg, lon_min, depth, station, comment
BCO-DMO Blog
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