Published September 8, 2025 | Version 1.0
Dataset Open

4DMED-2D Phytoplankton Functional Types (PFT) and Diffuse Attenuation Coefficients (Kd) (L3, 8 km, monthly, 2019–2021)

Authors/Creators

  • 1. EDMO icon Alfred Wegener Institute Helmholtz Centre for Polar and Marine Research
  • 2. ROR icon Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Contributors

Supervisor:

  • 1. ROR icon Alfred-Wegener-Institut Helmholtz-Zentrum für Polar- und Meeresforschung

Description

This dataset contains monthly Level-3 (L3) gridded maps (8 km resolution) of phytoplankton functional types (PFTs) and diffuse attenuation coefficients (Kd) for the period January 2019 to December 2021.

  • PFT products: Chlorophyll-a concentrations of diatoms, haptophytes, dinoflagellates, green algae, and prokaryotes [mg m⁻³], retrieved using the method described in Xi et al. (2021). Input satellite products were obtained from the Copernicus Marine Service.

  • Kd products: Diffuse attenuation coefficients in the UV and blue spectral ranges [m⁻¹], retrieved from Sentinel-5P TROPOMI using DOAS fitting of the vibrational Raman scattering (VRS) signal and radiative transfer–based LUTs, following Oelker et al. (2022). The LUTs and parameterizations were subsequently updated, and the current implementation is described in the S5P-PAL Product User Manual (PUM) (S5P-PAL data portal).

For the ESA 4DMedSea project, these products were aggregated into temporal and spatial scales suitable for clustering the Mediterranean Sea into ecological regions. Validation was performed against BGC-Argo profiles and additional in-situ datasets.

Data files are provided in NetCDF format, bundled into two compressed archives (PFT.zip and KD.zip). Each archive contains monthly fields for the full time period.

These datasets support studies of phytoplankton diversity, dissolved organic matter (DOM), and underwater light availability in the surface ocean, particularly in the Mediterranean Sea.

Files

Kd.zip

Files (79.9 MB)

Name Size
md5:34b5b016a1cbda026996f42c93aa8ad8
19.9 MB Preview Download
md5:f0a5034f48254071933abbfd39b2f1ef
60.1 MB Preview Download

Additional details

Funding

European Space Agency
4000141547/23/I-DT

References

  • Oelker, J., Rozanov, A., Richter, A., Rozanov, V., & Bracher, A. (2022). Retrieval of diffuse attenuation coefficients in the UV and blue spectral range from Sentinel-5P TROPOMI measurements. Frontiers in Marine Science, 9, 787992. https://doi.org/10.3389/fmars.2022.787992
  • S5P-PAL Data Portal (2025). TROPOMI Kd Products – Product User Manual. Available at: https://data-portal.s5p-pal.com/products/kd.html
  • Xi, H., Losa, S.N., Mangin, A., Garnesson, P., Bretagnon, M., Demaria, J., Soppa, M.A., d'Andon, O.H.F., Bracher, A., 2021. Global chlorophyll a concentrations of phytoplankton functional types with detailed uncertainty assessment using multi-sensor ocean color and sea surface temperature satellite products. J. Geophys. Res. Oceans, https://agupubs.onlinelibrary.wiley.com/doi/10.1029/2020JC017127
  • Xi, Hongyan; Wiegmann, Sonja; Hohe, Christian; Schmidt, Ina; Bracher, Astrid (2025): A validation data set of phytoplankton pigment concentrations and phytoplankton groups measured on water samples collected from various expeditions [dataset]. PANGAEA, https://doi.org/10.1594/PANGAEA.982433
  • MOi COpernicus Marine Service Evolution Project Glophyts (21036L05B-COP-INNO SCI-9000 )
  • ESA S5POC project (4000127533/19/I-NS-S5P+I-OC )
  • S5POC-PAL (Support Prototyping S5POC to PAL , ST-AWI-S5P_PAL-WO-012 and ST-AWI-S5P_PAL-WO-004)