Gradients 5 - Optics - LISST, AC-S, and ECO

This dataset was collected on the R/V Thompson during the Gradients V cruise which departed from San Diego, CA and ended in Honolulu, HI. A transect was performed on the 140 degree longitude line from roughly 16 degrees N to 4 degrees S before heading to Honolulu. Three biooptical instruments were plumbed to the underway uncontaminated seawater (intake depth 8m). Data for each instrument were averaged to the minute and matched to a timestamp on the minute.  LISST:  Filtered values (<0.2 um) removed from all data. The summed volume concentration of particles (in uL/L), the standard LISST output, is presented for 3 size ranges: 1.25-2 µm, 2-20 µm, and 20-100 µm. Note that data have not been processed to remove outliers. AC-S: Filtered values (<0.2 um) removed from all data (see White et al., 2017, GRL); data corrected for residual temperature and scattering; AC-S chl a concentrations obtained from a Gaussian fit over absorbance spectra in the red portion of the spectrum, assuming in vivo chl-a specific absorption of 0.0203 m2/mg at 674 nm. ECO: filtered values (<0.2 um) removed from chl and volume scattering data; chl fluorescence converted to mg/m3 using factory calibrations, and corrected to HPLC chlorophyll values. CDOM not included due to faulty channel. Time is in UTC.