This service provides solar energy at various depths below the surface of the sea in a given location, expressed as latitude and longitude, and for a given day. The quantity provided is a vertical profile of the PAR (photosynthetically available radiation).

The PAR is an energy, expressed here in Wh/m2 (multiply by 0.36 to obtain J/cm2, or by 3600 to obtain J/m2).

The profile can be computed for daily integrated PAR or hourly PAR. Hours are expressed in True Solar Time. Convention is that 12h means hourly period ranging from 11h30 to 12h30, contrary to the standard convention in meteorology wherein 12h means the hourly period ranging from 11h to 12h.

Inputs are geographical coordinates, day and hour under concern if appropriate. The profile of biomass is assumed to be a Gaussian function. User must provide the background biomass per volume unit (c0, in mg/m3), the total biomass per surface unit (ct, in mg/m2), the scale parameter for width of peak (sigma, in m) and the depth of chlorophyll maximum (zmax, in m).

The service should be limited to Case 1 waters. The irradiation database underlying the service is the HelioClim database, computed from the series of Meteosat images.

The service was established in close collaboration with Richard Santer and Eric Dilligeard, Université du Littoral, Wimereux, France. The methodology is explained in two documents: one for the equations, the other for the flowchart.