Code for ancient ocean 5 box model on euxinic/ferruginous balance and the nitrogen cycle

Code for ancient ocean 5 box model on euxinic/ferruginous balance and the Nitrogen cycle, by Richard Boyle 2018 .This paper was a deep-time adaptation of a contemporary ocean box model: Canfield, D. E. Models of oxic respiration, denitrification and sulphate reduction in zones of coastal upwelling. Geochim. Cosmochim. Act 70, 5753-5765 (2006). The main difference is the inclusion of direct limitation of export production by reduced nitrogen. This is only a semi-quantitative box model and the results discussed in the paper are parameter sensitive.