Comparing satellite and BGC-Argo chlorophyll estimation: A phenological study
| Type | : | ACL |
|---|---|---|
| Nature | : | Production scientifique |
| Au bénéfice du Laboratoire | : | Oui |
| Statut de publication | : | Publié |
| Année de publication | : | 2025 |
| Auteurs (6) | : | BAUDENA Alberto RIOM Wilhem TAILLANDIER Vincent MAYOT Nicolas MIGNOT Alexandre D'ORTENZIO Fabrizio |
| Revue scientifique | : | Remote Sensing of Environment |
| Volume | : | 326 |
| Fascicule | : | |
| Pages | : | |
| DOI | : | 10.1016/j.rse.2025.114743 |
| URL | : | https://www.sciencedirect.com/science/article/pii/S0034425725001476 |
| Abstract | : | Ocean primary production is a key process that regulates marine ecosystems and the global climate, but its estimation is still affected by multiple uncertainties. Typically, the chlorophyll-a concentration (CHL) is used to characterise this process, as it is considered as a proxy of phytoplankton biomass. To date, the most common observing systems for studying CHL are ocean colour satellites and Biogeochemical-Argo (BGC-Argo) floats. These are complementary systems: satellite observations provide global coverage but are limited to the ocean surface, while BGC-Argo floats provide punctual observations along the whole water column. Quantitative matching of these two observing systems has been obtained only at regional or single-float scales, while at a global scale the relatively low and irregular BGC-Argo coverage results in large uncertainties. Here, we propose a different method, by comparing satellite and BGC-Argo climatological annual time series within seven different bioregions, each characterised by a homogeneous phytoplankton phenology, allowing us to smooth the uncertainties. By comparing the mean values, amplitudes, and shapes of the two time series, we identify regions (a) where they agree (58%–61% of the ocean surface area); (b) regions undersampled by the BGC-Argo float network (particularly in the Arabian Sea and near the Amazon delta); (c) where the discrepancy may stem from satellite or (d) BGC-Argo performance (mainly found at subtropical and high latitudes, respectively). Caution is required when using BGC-Argo and satellite data in regions b–d, and, for each region, we provide suggestions on which system could be affected by the largest uncertainties. |
| Mots-clés | : | BGC-Argo drifter; Bioregionalisation; Marine chlorophyll; Phenology; Satellite-derived chlorophyll; Satellite BGC-Argo chlorophyll differences; Satellite BGC-Argo comparison; Time series analysis |
| Commentaire | : | - |
| Tags | : | - |
| Fichier attaché | : | - |
| Citation | : |
Baudena A, RIOM W, Taillandier V, Mayot N, Mignot A, D'Ortenzio F (2025) Comparing satellite and BGC-Argo chlorophyll estimation: A phenological study. Remote Sens Environ 326 | doi: 10.1016/j.rse.2025.114743
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