Dataset: Wirewalker data

RBR Ruskin software was used to download data and export as a text file.

MatLab was used for all subsequent data processing.

QUALITY CONTROL STEPS:

Minimal QC was required for this dataset. The raw temp, sal, PAR were in good shape. The bio-optics required minor adjustment as described below.

FL contained spurious negative values (0.1% of the total). These were modified with a criteria that set values < 50 (lowest dark counts) to 50.

bbp contained spurious negative values (0.08% of the total). These were modified with a criteria that set values < 50 (lowest dark counts) to 50.

CDOM contained spurious high points (0.18% of the total) and negative values (3.2% of the total). These were modified with a criteria that set values < 41 (lowest dark counts) to 41, and values > 55 to 44 (median value).

CORRECTION FOR NON-PHOTOCHEMICAL QUENCHING

The FL data show a clear diel pattern in the upper 30 m, correlated with PAR. This quenching during high light is attributed to NPQ of fluorescence. Therefore as a first steps toward getting values useful for calibration to mgChl/m^3, the data was corrected for this signal. The correction was obtained from a linear regression between the PAR and raw FL values at each depth bin. These regressions show a relatively linear relationship over the course of each 24 hour period, with the highest FL observed at night and quenching during higher light conditions. The daytime quenching is adjusted based on the slope and intercept at each depth to approximately match the night-time values.