POSTER SESSION 3
15:30–17:30, Wednesday, September 16
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
ABSTRACT 1240 | POSTER 55
ASSESSING PHYTOPLANKTON COMMUNITY COMPOSITION FROM PACE: FROM REFLECTANCE TO ABSORPTION AND PIGMENTS IN EUROPEAN WATERS
Phytoplankton play a fundamental role in marine ecosystems, driving food webs, biogeochemical cycles, and climate regulation. Their pigment composition is essential for assessing both biomass and taxonomic structure, but significant uncertainties remain in pigment retrieval, especially in complex coastal waters.
Improving hyperspectral bio-optical algorithms is therefore crucial for satellite ocean-colour applications, supporting missions such as PACE, FLEX, and CHIME, and strengthening our ability to monitor phytoplankton ecology across spatial and temporal scales.
This work leverages the comprehensive optical and biogeochemical dataset collected during the Tara Europa 2023–2024 expedition, which includes HPLC pigment data, phytoplankton absorption (aph(λ)) and non-algal particles absorption (aNAP(λ)) from filter-pad measurements, together with AC-S inline observations of particulate beam attenuation (cp(λ)) and absorption (ap(λ)). In addition, above-water hyperspectral remote-sensing reflectance Rrs(λ) data were collected from a Solar tracking radiometry platform (So-Rad).
Building on a previous refinement of the Gaussian decomposition approach of Chase et al. (2013), which improved the derivation of aph(λ) through the separation of aNAP(λ) from AC-S ap(λ) measurements, this study combines inline aph(λ) and hyperspectral Rrs(λ) observations. A Random Forest model is used to relate Rrs(λ) to the Gaussian amplitudes describing aph(λ), enabling the reconstruction of phytoplankton absorption spectra and the retrieval of diagnostic pigments from reflectance alone. The relative contribution of major phytoplankton pigment groups provides an overview of phytoplankton community composition.
This approach is further applied to PACE satellite data to support coastal ecosystem monitoring and improve the interpretation of phytoplankton variability across diverse European waters.
Margherita Costanzo*, Istituto di Scienze Marine (ISAMR), Consiglio Nazionale delle Ricerche (CNR), Italy, [email protected], https://orcid.org/0009-0008-3583-7843
Vittorio E. Brando, Istituto di Scienze Marine (ISAMR), Consiglio Nazionale delle Ricerche (CNR), Italy, [email protected]
Emmanuel Boss, School of Marine Sciences, University of Maine, USA, [email protected]
Alison P. Chase, Applied Physics Laboratory, University of Washington, USA, [email protected]
David Doxaran, Laboratoire d’Océanographie de Villefranche, CNRS-Sorbonne Université, France, [email protected]
Thomas M. Jordan, Plymouth Marine Laboratory, United Kingdom, [email protected]
Stefan G. H. Simis, Plymouth Marine Laboratory, United Kingdom, [email protected]
Poster Session | 1 | 2 | 3 | 4 | Schedule at a Glance
