Uncertainties in Chlorophyll-A Concentration Estimation from OLCI Satellite Data Over the Sea of Japan in April 2023 Due to the Presence of Dust in the Atmosphere

The occurrence of a high concentration of absorbing dust aerosol over the sea surface significantly complicates satellite measurements of the Ocean Color characteristics. This study presents an analysis of the variability of satellite estimates of the chlorophyll-a (Chl-a) concentration during the transfer of mineral dust over the Sea of Japan in April 2023. This transfer is confirmed not only by visual analysis of satellite images, but also by the calculation results of the SILAM software package. Statistical processing of OLCI satellite data for the central and northeastern parts of the Sea of Japan shows that on the days of a high concentration of mineral dust over the region, the Chl-a concentration sharply increased by 3–4 times compared to the average monthly values. This is a clear consequence of the atmospheric correction error, since even if mineral dust affects an increase in the Chl-a due to the deposition of mineral substances into the upper layer of the sea, this effect cannot occur immediately. This study examines possible causes of this error, namely physically incorrect values of the remote sensing reflectance (Rrs(λ)) of the Sea of Japan obtained during standard processing of OLCI data.