Towards operational 3D-Var assimilation of chlorophyll Biogeochemical-Argo float data into a biogeochemical model of the Mediterranean Sea

• DOI: 10.1016/j.ocemod.2018.11.005
• Publication Date: 2018-11-30T11:30:02Z
• Authors: G. Cossarini; L. Mariotti; L. Feudale; A. Mignot; S. Salon; V. Taillandier; A. Teruzzi; F. D'Ortenzio
• Keywords: Argo; Biogeochemical Cycle

The emerging availability of Biogeochemical-Argo (BGC-Argo) float data creates new opportunities to combine models and observations in investigations the interior structures dynamics marine ecosystems. An existing variational assimilation scheme (3DVarBio) has been upgraded coupled with Copernicus Marine Environment Monitoring Service biogeochemical model Mediterranean Sea assimilate BGC-Argo chlorophyll profile observations. Our results show that is feasible. Moreover, proposed framework provides significant corrections concentrations able consistently re-adjust shapes profiles during surface blooms occurring winter vertically mixed conditions, case summer deep maxima. Sensitivity analysis diagnostic metrics have applied evaluate impact relevance different factors 3DVarBio method. A key factor observation error tuned on a monthly basis incorporate representation error. Different frequencies cycle tested: daily or 3-day fosters highest skill performances despite reduced impacts increase computational burden. Considering present size network (about 15 floats) estimated non-homogeneous correlation radius length scale (15.2 km average), can constrain phytoplankton along whole water column over an area up 10% Sea.