The Biogeochemistry with LIght, Nutrients and Gases (BLING) model was developed with collaborators at Princeton / GFDL as an intermediate-complexity tool to approximate global biogeochemical cycling of key elements and their isotopes (Galbraith Biogeosciences 2010). The first version of the model (v0) included one macronutrient element, nominally termed phosphorus (though intended to represent an average of P and N), and the micronutrient iron.

BLING is more complex than many biogeochemical modules in that it simulates a dynamic multi-source iron cycle with flexible Fe:C stoichiometry and adaptive light limitation. To reduce computational overhead, BLING does not carry explicit tracers of particulate organic matter, calculating them diagnostically from the environment at each time step. This prevents a direct estimate of the transport of living matter by ocean circulation, but the resulting error is small under most conditions, particularly when a dissolved organic matter component is included (Galbraith JAMES 2015). The advantage is a large reduction in the number of tracers required, which reduces the computational burden and allows additional isotopic tracers to be included with minimal code.

The reduction of tracer number was taken a step further with miniBLING, for which the dissolved organic pool was removed and a fixed climatology was used for the dissolved Fe field, thus requiring only one tracer, ‘PO4’ (Galbraith JAMES 2015).

BLING and miniBLING were originally written in FORTRAN (F90) for the GFDL model and are available in the public release of MOM on github.

BLING was incorporated into the main GFDL model development and an updated version 2 released (Dunne et al. 2020).