REFINE will be implemented along….

2019: Technological development of
REFINE floats

These floats will have, in particular

  • Extended battery packs for longer mission
  • New electronic for targeted exploration and adaptative sampling
  • New sensors for particles and zooplankton characterization

Outreach & Communication

The REFINE’s TEAM is strongly committed in developing Ocean Literacy through:

  • The « mon océan & moi » programme
  • The « adopt a float » programme
  • The Journal « Frontiers for Young Minds – The Ocean »

Float deployments start

Five key areas are targeted:

Float mission supervision

Beside standard Argo mission, the float’s data acquisition will be continuously fine-tuned to explore and quantify

  • Export events following spring blooms
  • Carbon flux attenuation within twilight zone at seasonal and annual scale
  • Diel and seasonal vertical migration of zooplankton

Float Data qualification

The data management and distribution will rely on:

  • International procedures for core BGC-Argo variables
  • The development of new procedures for additional sensors

Data analysis and synthesis

Thanks to the high-quality and uniquely interoperable acquired datasets we ambition to:

  • Develop comparative Twilight Zone carbon budget in the key regions
  • Develop mechanistic and empirical linkage between euphotic zone processes fluxes with twilight zone processes and fluxes
  • Explore the main drivers of carbon injection into and transformation within the TZ
  • Explore the contribution of physically-mediated vs biologically-mediated pump in the overall carbon pump budget
  • Thanks to artificial Intelligence: upscale and integrate the regional knowledge to global scale
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The Twilight Zone, located between the depths of ~ 100 m and 1000 m, is one of the least known environments on Earth: we mandatorily need to explore it as it provides essential services for our society and is pivotal to the ocean carbon cycle


REFINE ambitions to implement breakthrough in situ robotic process studies based on a new generation of highly instrumented jumboized profiling floats


The breakthrough robotic process studies will be first implemented in five key oceanic regions representative of diversity of global oceanic biogeochemical conditions and responses to climate change.

South Atlantic Sub-tropical Gyre (REFINE Province 1)

The Guinea Dome (REFINE Province 2)

Labrador Sea (REFINE Province 3)

Kerguelen Plateau (REFINE Province 4)

Baffin Bay (REFINE Province 5)


The REFINE’s approach is to distribute the robotic process studies over a large latitudinal gradient to cover a broad scope of stratification, mixing, irradiance and nutrient conditions. As these environmental conditions are the main drivers of phytoplankton dynamics and composition, it is expected a wide range of Twilight Zone biogeochemical responses. For REFINE, the five oceanic provinces are located in three main latitudinal areas.

See on the map

Low latitude areas

Low latitude areas are characterized by permanently stratified conditions with low nutrient supply and weak seasonality in phytoplankton production.

  • Subtropical gyres (40 % of the Ocean surface) are the lowest-production systems of the open-ocean , and REFINE Province 1 will be the South Atlantic Sub-tropical Gyre.
  • In contrast, the quasi-permanent cyclonic doming structures associated with eastern subequatorial waters are hotspots of high primary production and REFINE Province 2 will be the Guinea Dome.

Temperate and sub-polar areas

Temperate and sub-polar areas are characterized by marked seasonal signals in phytoplankton dynamics with the occurrence of a spring/summer phytoplankton bloom. The magnitude of this bloom reflects distinctive regional, nutrient-driven, differences.

  • The North Atlantic subpolar gyre hosts the largest spring/summer blooms in the global ocean, with associated large export through gravitational sinking. REFINE Province 3 will be the strong- blooming Labrador Sea.
  • At similar latitudes in the Southern Ocean, the iron-limited conditions impact on phytoplankton cycle and blooms and subsequent potential export in the twilight zone. REFINE Province 4 will be the iron-limited upstream waters of the Kerguelen Plateau.

The North Polar areas

Arctic Ocean is characterized by an extreme range of seasonal surface irradiance, which forces a distinctive response in phytoplankton and hence ecosystem dynamics. The productive period is tightly related to the seasonal dynamics of the sea ice (coverage and thickness), and the early summer phytoplankton bloom develops at the retreating sea ice edge favored by the associated salinity stratification. REFINE Province 5 will be Baffin Bay.

  • (1) Claustre, H., A. Sciandra, and D. Vaulot (2008). Introduction to the special section bio-optical and biogeochemical conditions in the South East Pacific in late 2004: the BIOSOPE program. Biogeosciences, 5(3), 679-691.
  • (2) Karstensen, J., L. Stramma, and M. Visbeck (2008). Oxygen minimum zones in the eastern tropical Atlantic and Pacific oceans. Progress in Oceanography, 77(4), 331-350, doi:10.1016/j.pocean.2007.05.009.
  • (3) Duteil, O., A. Lazar, Y. Dandonneau, I. Wainer, and C. Menkes (2009). Deep chlorophyll maximum and upper ocean structure interactions: Case of the Guinea Thermal Dome. Journal of Marine Research, 67(2), 239-271.
  • (4) Siegel, D.A., S.C. Doney, and J.A. Yoder (2002). The North Atlantic Spring Phytoplankton Bloom and Sverdrup's Critical Depth Hypothesis. Science, 296(5568), 730-733.
  • (5) Ardyna, M., H. Claustre, J. B. Sallee, F. D'Ovidio, B. Gentili, G. van Dijken, F. D'Ortenzio, and K. R. Arrigo (2017), Delineating environmental control of phytoplankton biomass and phenology in the Southern Ocean, Geophysical Research Letters, 44(10), 5016-5024, doi:10.1002/2016gl072428.
  • (6) Perrette, M., A. Yool, G.D. Quartly, and E.E. Popova (2011). Near-ubiquity of ice-edge blooms in the Arctic. Biogeosciences, 8(2), 515-524, doi:10.5194/bg-8-515-2011.


We are a team of experienced scientists and engineers hosting outstanding PhD students and post-docs. Since more than 15 years, we are deeply involved in the development of autonomous platforms and of innovative ways to conduct remote observations of oceanic biogeochemical processes. We are additionally very active in using these new approaches for scrutinizing the ocean to develop and promote outreach in support of Ocean Literacy.


Coming Soon


After remOcean, Hervé Claustre was awarded a 2nd ERC Research Advanced Grant.
His new project REFINE (erc-refine.eu) focuses on the Ocean Carbon Pump with a particular emphasis on the Ocean Twilight Zone.