High-resolution dataset of chlorophyll-a and cyanobacterial blooms in the southern Baltic Sea (2023-2024)

This dataset provides high-resolution information on the spatial and temporal variability of chlorophyll-a and cyanobacterial blooms in the southern Baltic Sea for 2023–2024. It was developed within the CSI-POM Stage 2 project by combining Sentinel-3 OLCI satellite observations, machine-learning methods, and numerical modelling.

Sentinel-3 OLCI observations (300 m spatial resolution) were processed using POLYMER atmospheric correction and quality-control procedures. Total chlorophyll-a concentration (chlaTot) was estimated using a Support Vector Regression (SVR) model. Cyanobacterial biomass was characterised through phycocyanin concentration (PC) and cyanobacteria-associated chlorophyll-a (chlPC). The processed satellite products were aggregated into daily datasets.

Satellite-derived chlorophyll-a fields were also assimilated into the 3D CEMBS-PolSea hydrodynamic-biogeochemical model with a spatial resolution of approximately 575 m. The dataset covers the Polish Marine Areas and adjacent waters of the southern Baltic Sea (approximately 13°30′–21°30′E, 53°50′–55°45′N). Data are provided in NetCDF4 format compliant with CF metadata conventions.

The dataset is intended for environmental monitoring, satellite and numerical model validation, studies of eutrophication and cyanobacterial blooms, and the development of marine early-warning and management applications.

License and data attribution

This derived dataset is made available under the Creative Commons Attribution 4.0 International (CC BY 4.0) license, insofar as copyright and database rights in the derived products are held by the dataset authors and/or their institutions.

Source satellite data: Contains modified Copernicus Sentinel data 2023–2024.

The underlying Copernicus Sentinel data remain subject to the Legal Notice on the use of Copernicus Sentinel Data and Service Information.