Deployment 2011 to 2012:
calibration info for RBR CTD onboard the BS3 CMP

Conductivity The conductivity sensor of the CMP's onboard RBR CTD was calibrated by comparing it to the SeaBird SBE 37 "microcat" (MC) located below the CMP's bottom stop. After successively eliminating outliers, a conductiviy slope correction was determined as a linear fit to their conductivity difference (Fratantoni et al. 2006). This figure indicates that short-term larger differences related to bottom intensified intrusions of warmer, saltier water were eliminated as outliers. A "sanity check" based on the initial, unprocessed CMP data as generated during the cruise ("proc_ini") and the postcruise-calibrated MC confirmed that outside of these intrusions, the CMP and MC conductivity were very close. A detailed view further suggested that the small conductivity correction further improved the comparison:

Following these checks, the conductivity correction plotted below was applied. Temperature: We typically do not field calibrate the CMP temperature sensor. As a check, the near-bottom CMP readings were again compated to the microcat data. They agreed well outside of the instrusions described above. Therefore, no adjustment was made. ---------- References ---------- Fratantoni, P. S., R. S. Pickart, S. Zimmerman, and M. Schwartz, 2006. Western Arctic Shelf-Basin Interactions Experiment: Processing of moored profiler data from the Beaufort Shelf Edge mooring array. WHOI Technical Report No WHOI-2006-15.