Abstract. A multiplatform assessment of the Ocean–Atmosphere Spectral
Irradiance Model (OASIM) radiative model focussed on the Mediterranean Sea
for the period 2004–2017 is presented. The BOUée pour l'acquiSition
d'une Série Optique à Long termE (BOUSSOLE) mooring and
biogeochemical Argo (BGC-Argo) float optical sensor observations are
combined with model outputs to analyse the spatial and temporal
variabilities in the downward planar irradiance at the ocean–atmosphere
interface. The correlations between the data and model are always higher
than 0.6. With the exception of downward photosynthetic active radiation and
the 670 nm channel, correlation values are always higher than 0.8 and, when
removing the inter-daily variability, they are higher than 0.9. At the scale
of the BOUSSOLE sampling (15 min temporal resolution), the root mean
square difference oscillates at approximately 30 %–40 % of
the averaged model output and is reduced to approximately 10 % when the
variability between days is filtered out. Both BOUSSOLE and BGC-Argo
indicate that bias is up to 20 % for the irradiance at 380 and 412 nm and for wavelengths above 670 nm, whereas it decreases to less than 5 %
at the other wavelengths. Analysis of atmospheric input data indicates that
the model skill is strongly affected by cloud dynamics. High skills are
observed during summer when the cloud cover is low.
Assessment of the spectral downward irradiance at the surface of the Mediterranean Sea using the radiative Ocean-Atmosphere Spectral Irradiance Model (OASIM)
