Development of BFMCOUPLER (v1.0), the coupling scheme that links the MITgcm and BFM models for ocean biogeochemistry simulations
Gianpiero Cossarini1, Stefano Querin1, Cosimo Solidoro1, Gianmaria Sannino2, Paolo Lazzari1, Valeria Di Biagio1, and Giorgio Bolzon11Department of Oceanography, Istituto Nazionale di Oceanografia e di Geofisica Sperimentale - OGS, Sgonico (TS), 34010, Italy 2UTMEA - CLIM Laboratory, ENEA, Rome, 00123 Italy
Received: 27 Aug 2016 – Accepted for review: 14 Sep 2016 – Discussion started: 15 Sep 2016
Abstract. In this paper, we present a coupling scheme between the Massachusetts Institute of Technology general circulation model (MITgcm) and the Biogeochemical Flux Model (BFM). The MITgcm and BFM are widely used models for geophysical fluid dynamics and for ocean biogeochemistry, respectively, and they benefit from the support of active developers and user communities. The MITgcm is a state-of-the-art general circulation model for simulating the ocean and the atmosphere. This model is fully three dimensional (including the non-hydrostatic term of momentum equations) and includes a finite-volume discretization and a number of additional features enabling simulations from global (O(107)m) to local scales (O(100)m). The BFM is a complex biogeochemical model that simulates the cycling of a number of constituents and nutrients within marine ecosystems. The coupler presented in this paper links the two models through an efficient scheme that manages communication and memory sharing between the models. We also test specific model options to balance the numerical accuracy against the computational performance. The coupling scheme allows us to solve several processes that are not considered by each of the models alone, including light attenuation parameterizations along the water column, phytoplankton and detritus sinking, external inputs, and surface and bottom fluxes. Moreover, this new coupled hydrodynamic-biogeochemical model has been configured and tested against an idealized problem (a cyclonic gyre in a mid-latitude closed basin) and a realistic case study (central part of the Mediterranean Sea in 2006–2012). The numerical results are consistent with the expected theoretical and observed behaviour of both the idealized system and the Mediterranean domain, thus demonstrating the applicability of the new coupled model to a wide range of ocean biogeochemistry problems.
Cossarini, G., Querin, S., Solidoro, C., Sannino, G., Lazzari, P., Di Biagio, V., and Bolzon, G.: Development of BFMCOUPLER (v1.0), the coupling scheme that links the MITgcm and BFM models for ocean biogeochemistry simulations, Geosci. Model Dev. Discuss., doi:10.5194/gmd-2016-222, in review, 2016.