EGU25-15937, updated on 15 Mar 2025
https://doi.org/10.5194/egusphere-egu25-15937
EGU General Assembly 2025
© Author(s) 2025. This work is distributed under
the Creative Commons Attribution 4.0 License.
IBIRYS: a Regional High-Resolution Reanalysis (physical and biogeochemical) of the last 30 years (1993-2023) over the European Northeast Shelf
Bruno Levier1, Romain Escudier1, Elodie Gutknecht1, Guillaume Reffray1, Sylvain Cailleau1, Roland Aznar2, Stefania Ciliberti2, Marcos Sotillo2, and Álvaro de Pascual2
Bruno Levier et al.
  • 1MERCATOR OCEAN 2 avenue de l’aérodrome de Montaudran 31400 Toulouse, France
  • 2NOW Systems, C/Lope Gómez de Marzoa s/n, Local 14, Santiago de Compostela 15705, Spain

Mercator-Ocean has developed a regional reanalysis over the Northeast Atlantic (IBI: Iberia, Biscay and Irish), called IBIRYS. The reanalysis was first delivered in 2015 in the framework of the MyOcean project, and has since been regularly updated, now delivered on the Copernicus Marine Service datastore. It also contributes to the annual Copernicus Ocean State Report, and Ocean Monitoring Indices are calculated from the reanalysis to monitor the health of the ocean. 

NEMO modelling platform resolves ocean dynamics and thermodynamics, and the lower trophic levels’ ecosystem dynamics is simulated by the PISCES biogeochemical model. The two components are coupled “online”. The data assimilation system (Mercator Ocean assimilation system SAM2) allows constraining the physical model in a multivariate way with Sea Surface Temperature, together with all available satellite Sea Level Anomalies, and with in-situ observations. In addition to SAM2, a large bias correction is also applied. The new release of the reanalysis, expected to be on Copernicus products’ catalogue in 2025, is now at 1/36° resolution, and benefits from updates of the models (for physics and biogeochemistry), of the data assimilation system, and input data. 

In this presentation, we present the assessment of the new reanalysis for both physical and biogeochemical components. We compare the new reanalysis to the former one, and to the Mercator Ocean global reanalysis GLORYS. We also assess physical and biogeochemical components in confrontation with classical observations (SST, in-situ profiles, etc). 

How to cite: Levier, B., Escudier, R., Gutknecht, E., Reffray, G., Cailleau, S., Aznar, R., Ciliberti, S., Sotillo, M., and de Pascual, Á.: IBIRYS: a Regional High-Resolution Reanalysis (physical and biogeochemical) of the last 30 years (1993-2023) over the European Northeast Shelf, EGU General Assembly 2025, Vienna, Austria, 27 Apr–2 May 2025, EGU25-15937, https://doi.org/10.5194/egusphere-egu25-15937, 2025.