Parameter: beam_c

Dataset: 
Park phase data
Parameter: 
beam attenuation
Master parameters information
Short Name:
 beam_cp
Short Description:
 beam attenuation
Official Name:
 beam_cp
No Data Value:
 nd
Description:
 

attenuation (loss of light) of a narrow, well collimated beam of light; beam attenuation due to particles; the particulate beam attenuation coefficient (cp)

Dataset-parameters information
Supplied Name: 
beam_c
Supplied Units: 
m -1
Conversion Necessary: 
no
No Data Value: 
nd
Description: 

Uncorrected particulate beam attenuation coefficient cp (650 nm); Acquired with WET Labs c-ROVER 2000 transmissometer with 650-nm wavelength and 0.25-m pathlength.

Transmittance is calculated as:

Transmittance = (Signal - Dark) / (Cal Signal - Dark)
Signal = raw output in counts
Dark = counts with beam blocked, factory supplied
Cal Signal = counts with Milli-Q water in sensor path, acquired prior to deployment (https://www.bco-dmo.org/dataset/728371)

The beam attenuation coefficient is calculated as:

cp,uncorr(650 nm) = -ln (transmittance) / pathlength [m]

No correction for drift of the sensor over time (for instance, due to bio-fouling, see Estapa et al. 2013) has been applied.