Starting in June 2026, Argo chlorophyll-a data will be reprocessed and redistributed by the Data Assembly Centers (DACs) using a new correction.

This update will significantly improve data quality and accuracy but may also have important implications for end users. If you use these data for analyses, models, or publications, your results could be affected.

We strongly encourage all users of Argo chlorophyll-a data to join a dedicated webinar, where the following topics will be covered:

• What is changing
• Why this new correction is being implemented
• Potential impacts on your work
• Recommended best practices

Webinar date & time: Tuesday, 12 May 2026, 16:00 CEST / 14:00 UTC

Title: Chlorophyll-a update in BGC-Argo: What’s Changing in June 2026, How It Works, and Why It Matters?

Presenter: Raphaëlle Sauzède, CNRS – Institut de la Mer de Villefranche

Description:

Chlorophyll-a concentration (Chla), a key indicator of phytoplankton biomass, is essential for understanding ocean ecosystems. While BGC-Argo floats have revolutionized global Chla monitoring, accurately converting fluorescence data into Chla estimates remains a significant challenge. In June 2026, a new real-time adjustment methodology will be implemented for Chla into the Argo data stream. This presentation will detail the methodology based on 4D-BGC products, the timeline for operationalization, and the broader implications of this update for ocean science and operational applications.

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Stay informed: Join the Argo mailing list to receive timely updates about this CHLA reprocessing and other key future Argo developments.