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Maritime Forum

Map of the Week - Chlorophyll-a

The Map of the Week shows the monthly global surface ocean chlorophyll-a concentration.


This week, Mercator Ocean International hosted the first Digital Ocean Forum in Paris, France, on the 20th and 21st of April. The Digital Ocean Forum 2022 is organized as a response to the EU Mission “Restore our Oceans and Seas by 2030” and to the call made at the One Ocean Summit on 11 February 2022 in Brest (France) towards the construction of the European Digital Twin Ocean (DTO) based on European Assets such as Copernicus and EMODnet. A digital twin is a digital representation of real-world entities or processes. Digital twins use real-time and historical data to represent the past and present, and create models to simulate future scenarios. The European Digital Twin Ocean's ambition is to make ocean knowledge readily available to citizens, entrepreneurs, scientists and policy-makers by providing them with an innovative set of user-driven, interactive and visualisation tools.[1] Mercator Ocean International takes the lead in federating the European communities concerned, for building a European DTO based on French and European innovations and in coordination with the United Nations Decade of Ocean Sciences.

The objective of the Forum is to provide the most complete, comprehensive and consistent responses possible, leading to the co-design of European Open & Public Digital Twin of the Ocean built on European existing assets and innovation. EMODnet experts joined the Forum live, creating a common vision for a future DTO. EMODnet is a committed collaborator with Mercator Ocean International and Copernicus Marine Service to deliver the core public marine data service and data space for the DTO.

Did you know that chlorophyll is an indicator for ocean primary productivity? The Map of the Week shows the monthly global surface ocean chlorophyll-a concentration. This product is derived from multiple optical satellite sensors (SeaWiFS, MODIS-Aqua, MERIS, VIIRSN and OLCI-S3A) and calculated using the Copernicus GlobColour processor. It shows the average Chlorophyll-a concentration (in mg per cubic meter) at the ocean surface during the last month in regions which were not covered by clouds. Chlorophyll is an indicator for the abundance of photosynthetic plankton, the primary producers of the ocean. Phytoplankton are microscopic single-celled algae that drift at the surface of the ocean and they contain the green pigment chlorophyll, which allows them to use the energy of sunlight to transform CO2 to sugars and oxygen. Because of the distinct green colour of the chlorophyll pigment, we can use optical satellite sensors to visualise the distribution of chlorophyll and thus the phytoplankton in our oceans.

Wish to know more?

  • Explore the Map of the Week and zoom in to visualize the monthly mean chlorophyll-a concentration in your region.
  • Learn more about the European Digital Twin Ocean here and from this infographic.

Access the map

The data in this map are provided by Copernicus Marine Service.