TY - JOUR T1 - Chromophoric dissolved organic matter dynamics revealed through the optimization of an optical-biogeochemical model in the NW Mediterranean Sea A1 - Álvarez,Eva A1 - Cossarini,Gianpiero A1 - Teruzzi,Anna A1 - Bruggeman,Jorn A1 - Bolding,Karsten A1 - Ciavatta,Stefano A1 - Vellucci,Vincenzo A1 - D’ortenzio,Fabrizio A1 - Antoine,David A1 - Lazzari,Paolo AD - National Institute of Oceanography and Applied Geophysics - OGS, Trieste, 34010, Italy AD - Bolding & Bruggeman ApS, Asperup, 5466, Denmark AD - Plymouth Marine Laboratory, Plymouth, PL1 3DH, UK AD - Aarhus University, Department of Ecoscience, Silkeborg, 8600, Denmark AD - Mercator Ocean International, 31400 Toulouse, France AD - Sorbonne Université, CNRS, Institut de la Mer de Villefranche, IMEV, Villefranche-sur-Mer, F-06230, France AD - Sorbonne Université, CNRS, Laboratoire d’Océanographie de Villefranche, LOV, Villefranche-sur-Mer, F-06230, France AD - Remote Sensing and Satellite Research Group, School of Earth & Planetary Science, Curtin University, Perth, WA 6102, Australia UR - https://archimer.ifremer.fr/doc/00825/93669/ DO - 10.5194/bg-20-4591-2023 N2 - Chromophoric dissolved organic matter (CDOM) significantly contributes to the non-water absorption budget in the Mediterranean Sea. The absorption coefficient of CDOM, αCDOM(λ), is measurable in situ and remotely from different platforms and can be used as an indicator of the concentration of other relevant biogeochemical variables, e.g., dissolved organic carbon. However, our ability to model the biogeochemical processes that determine CDOM concentrations is still limited. Here we propose a novel parametrisation of the CDOM cycle that accounts for the interplay between the light- and nutrient-dependent dynamics of local CDOM production and degradation, as well as its vertical transport. The parameterization is included in a one-dimensional (1D) configuration of the Biogeochemical Flux Model (BFM), which is here coupled to the General Ocean Turbulence Model (GOTM) through the Framework for Aquatic Biogeochemical Models (FABM). Here BFM is augmented with a bio-optical component that revolves spectrally the underwater light transmission. We did run this new GOTM-FABM-BFM configuration to simulate the seasonal αCDOM(λ) cycle at the deep-water site of the BOUSSOLE project in the North-Western Mediterranean Sea. Our results show that accounting for both nutrient and light dependence of CDOM production improves the simulation of the seasonal and vertical dynamics of αCDOM(λ), including a subsurface maximum that forms in spring and progressively intensifies in summer. Furthermore, the model consistently reproduces the higher-than-average concentrations of CDOM per unit chlorophyll concentration observed at BOUSSOLE. The configuration, outputs and sensitivity analyses from this 1D model application will be instrumental for future applications of BFM to the entire Mediterranean Sea in a 3D configuration. Y1 - 2023/11 PB - Copernicus GmbH JF - Biogeosciences SN - 1726-4170 VL - 20 IS - 22 SP - 4591 EP - 4624 ID - 93669 ER -