Operational Visibility

English Channel and Bay of Biscay Demonstrator

Optical transparency of ocean waters flowing in the upper layer of the English Channel and the Bay of Biscay is presented. Displayed images come from either satellite remote sensing or digital simulation (analysis and forecast). The parameters describing water transparency are the following:

Horizontal Visibility

expressed in meters, is the sighting range of a black disk target moved horizontally away from a diving observer (Duntley 1963).

Z Secchi

expressed in meters, is the vertical sighting range of a traditional Secchi disk lowered from a surface observer down to the water column (Preisendorfer 1986). The upper water column is assumed homogeneous on the vertical.

Products generated by ACRI-ST (Philippe Bryère), in the frame of the MCGS project, with a cooperation of IFREMER (Francis Gohin) and following specifications of SHOM (Frédéric Jourdin).