Dataset: CTD hydrocast data
Deployment: KM1910

CTD data were processed and quality controlled following Hawaii Ocean Time-series protocols.

CTD data were quality controlled and screened for spikes when the CTD rosette speed was less than 0.25 m s-1 or its acceleration was greater than 0.25 m s. Data were averaged into 2 dbar pressure bins.

CTD-based dissolved oxygen measurements were calibrated to discrete oxygen samples measured on the ship by Winkler titration. Discrete bottle oxygen samples were collected and analyzed using a computer-controlled potentiometric end-point titration procedure. Precision of the Winkler titration method averages ~0.2%. The calibration procedure consists of fitting a non-linear equation to the CTD oxygen current and oxygen temperature.

Similarly, the SeaPoint fluorescence measurements were calibrated, post-cruise, to discrete bottle samples collected from selected hydrocasts. CTD sensor drift was corrected via calibration with bottle fluorometric chlorophyll a plus accessory pheopigments analyzed at the shore based laboratory using a Turner Designs Model 10-AU fluorometer. A linear relationship of the form, Vchl = b·Vfluor + a, was used to convert all fluorescence data to chloropigment.

BCO-DMO Processing Description:

* Merged all individual CTD files
* Combined CTD files with the eventlog, adding the latitude, longitude, times, cast number, station number and event number.
* Converted times to ISO format and Zulu times (HST to UTC time).
* Adjusted column names to comply with database requirements.