Parameter: chl_corr

Dataset: 
Parameter: 
Master parameters information
Short Name:
 chl_a
Short Description:
 chlorophyll a
Official Name:
 chlorophyll a
No Data Value:
Description:
 

Total chlorophyll a pigment. See dataset for units of measurement; often reported in: milligrams per cubic meter (mg/m3); micrograms/liter (ug/L); nanograms/liter (ng/L).

CAUTION Within JGOFS MERGED water column products: this parameter is derived from HPLC methodology and the units are nanograms/liter; however; this parameter name is also used for a variety of water and nonwater column sampling; derived via the fluorometric method; units will also vary.

Dataset-parameters information
Supplied Name: 
chl_corr
Supplied Units: 
ug/L
Conversion Necessary: 
no
Conversion Utility: 
No Data Value: 
nd
Description: 
Corrected chlorophyll-a; The fluorometric chlorophyll-a values derived above were further corrected by removing the deep-water dependence of chlorophyll fluorescence on fluorescent colored dissolved organic matter (CDOM; see below) and a small residual deep-water sensor offset. The method of Xing et al. (2017) was applied. Briefly chlorophyll fluorescence in deep water was assumed to originate entirely from a combination of the above factors the dependence of the measured chlorophyll fluorescence on CDOM was determined through linear regression and the regression parameters were used to correct the entire chlorophyll profile. Profiles shallower than 200 m were corrected using the regression parameters of the subsequent float profile.