Daily total of PAR The daily sum of photosynthetically active solar radiation in the 300-700 nm wavelength range (PAR) reaching the sea surface directly from the Sun and scattered in the atmosphere. Values expressed in [MJ•m­-2]. The SatBałtyk system presents this parameter in the form of maps with a 1 km spatial resolution. Methodology

The SolRad [1] model is used to determine the magnitude of the daily dose of PAR. It is calculated from values of the solar irradiance (radiation flux density) measured every 15 minutes. The input data for the model are obtained from the SEVIRI radiometer (HRV spectral channel) deployed on MSG series satellites, AVHRR, TOVS and SBUV/2 radiometers deployed on satellites of the TirosN/NOAA and Metop series, and from the UM or WRF meteorological models.

Validation The statistical error, expressed as the standard deviation of the differences between PAR fluxes measured in situ and those determined using the model for instantaneous values, was  σ=40.7 Wm-2. The systematic error (the mean difference between measured and calculated values) was estimated at -0.06 Wm-2. The empirical measurements (N=4199) used for validating the model were obtained from the pyranometer on r/v “Oceania”. They were made in 2010-2012 in the southern and central Baltic Sea.

Link to the parameter in SatBaltic System:
Daily total of PAR

[1] SolRad – model Solar radiation