This service provides solar energy just below the surface of the sea in a given location, expressed as latitude and longitude. The quantity provided is a time-series 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).

Available are time-series of daily PAR and 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.

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.