SEAN OC SOP 9: Post-season Quality Assurance: Calibration Evaluation version 1
Danielson S, Johnson W, Sharman L, Eckert G, Moynahan B. SEAN OC SOP 9: Post-season Quality Assurance: Calibration Evaluation version 1. NPS SEAN. Juneau, Alaska
After the October cruise, the CTD is returned to Sea-Bird for calibration of the sensors. If multiple CTDs were employed during the season, all must undergo calibration. All sensors on a CTD are to be calibrated. Because no water samples are taken for mid-season calibrations of the conductivity, fluorometers or nephelometers, the annual calibrations provide the only means for the program to independently assess sensor operations. The “Temperature Calibration Report” and “Conductivity Calibration Report” will detail sensor drift between the current and previous instrument calibrations. Use the “As Received” calibration values for purposes of determining drift during the period of instrument use. For Glacier Bay measurements, which describe a dynamic coastal domain, sufficient accuracy of temperature (ºC) and salinity (PSU) data are achieved at the 0.01 and 0.03 levels respectively; however typical measurements will perform better than this, on the order of 0.002–0.005 for the temperature measurements and 0.01–0.02 for the salinity measurements. Water samples are not taken during the Glacier Bay cruises, so the monitoring program has only limited ability to assess and correct deviant readings. After the calibration sheets have been inspected, a data quality flag will be assigned (see OC_M) to each CTD cast, according to the criteria listed below.
- Type
- Standard Operating Procedure
- Authors
- Danielson, Seth; Johnson, William; Sharman, Lewis; Eckert, Ginny; Moynahan, Brendan
- Publisher
- NPS SEAN. Juneau, Alaska
- Units
- GLBA , SEAN
- Keywords
- Alaska, chlorophyll a, CTD, fluorometer, Glacier Bay, Icy Strait, Monitoring, OBS, Oceanography, Oceans, PAR, photic depth, photosynthetically available radiation, physical oceanography, Pressure, Salinity, sigma-t, Temperature, Turbidity
- Subjects
- Ecological Framework: Water | Hydrology | Marine Hydrology