Supporting data and code for Verezemskaya et al. (2026), Biogeosciences

This deposit contains the preprocessed data products and Jupyter notebooks needed to reproduce all figures and Table 2 of Verezemskaya et al. (2026), Constraining the three-dimensional Black Sea ecosystem with multispectral satellite reflectance: an ensemble data-assimilation twin experiment, submitted to Biogeosciences. The paper reports a twin Observing System Simulation Experiment in which multispectral satellite remote-sensing reflectances are assimilated into the coupled NEMO-BAMHBI-RADTRANS model of the Black Sea using the SORDA ensemble Kalman filter. To keep the archive small, only the preprocessed regional metrics, DCM diagnostics and per-figure precomputed fields are shipped here (one small NetCDF per figure, plus the model grid); the per-member 20-member ensemble output of the free-run and the two assimilation experiments (1d_ref and 1d_rCHL), the paired OSSE reference truths, the analysis increments and the protocol-test ensembles underlying Fig. D1 and Table D1 are available from the corresponding author on reasonable request owing to their combined volume (~150 GB). Each figure has a plotting notebook that reads one small file from data/ and a paired preprocessing notebook that documents the full chain from raw ensemble to the shipped product. The SORDA code is open-source and tagged at the version used for this paper at https://gitlab.uliege.be/especes/mast/SORDA.