HOT-304 KOK1807 Optics - LISST, C-Star, AC-S, ECO

These Simons Collaboration on Ocean Processes and Ecology (SCOPE) data products were produced by the University of Hawaiʻi at Mānoa with support from the Simons Foundation. Four biooptical instruments were plumbed to the underway uncontaminated seawater on the R/V KOK for the HOT-304 cruise to Station ALOHA in the north Pacific Ocean. 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) are converted to carbon concentrations (umol C /L) using Mender-Deuer and Lessard (2000) conversion factor and is presented for 3 size ranges: 1.35-2 µm, 2-20 µm, and 20-100 µm. Particle volume concentration can be converted to particle concentration by assuming spherical particles. The total particle concentration (#/L) is calculated for particles with a diameter between 1.35 and 100 um. Larger size classes are excluded due to low detection limits and scattering at density gradients. Note that data have not been processed to remove outliers. C-star: beam attenuation coefficient at 650 nm with filtered values (<0.2 um) removed. 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. Beam attenuation coefficient is presented from 650nm. ECO: filtered values (<0.2 um) removed from chl and volume scattering data; chl fluorescence converted to mg/m3 using factory calibrations. The volume scattering is converted to particle backscattering coefficient following Boss and Pegau (2001). The timestamp is in UTC.