Tagliabue A. auteur aut IRD Aumont Olivier auteur aut IRD De Ath R. auteur aut IRD Dunne J. P. auteur aut IRD Dutkiewicz S. auteur aut IRD Galbraith E. auteur aut IRD Misumi K. auteur aut IRD Moore J. K. auteur aut IRD Ridgwell A. auteur aut IRD Sherman E. auteur aut IRD Stock C. auteur aut IRD Vichi M. auteur aut IRD Volker C. auteur aut IRD Yool A. auteur aut IRD text journalArticle eng text/pdf born digital access Numerical models of ocean biogeochemistry are relied upon to make projections about the impact of climate change on marine resources and test hypotheses regarding the drivers of past changes in climate and ecosystems. In large areas of the ocean, iron availability regulates the functioning of marine ecosystems and hence the ocean carbon cycle. Accordingly, our ability to quantify the drivers and impacts of fluctuations in ocean ecosystems and carbon cycling in space and time relies on first achieving an appropriate representation of the modern marine iron cycle in models. When the iron distributions from 13 global ocean biogeochemistry models are compared against the latest oceanic sections from the GEOTRACES program, we find that all models struggle to reproduce many aspects of the observed spatial patterns. Models that reflect the emerging evidence for multiple iron sources or subtleties of its internal cycling perform much better in capturing observed features than their simpler contemporaries, particularly in the ocean interior. We show that the substantial uncertainty in the input fluxes of iron results in a very wide range of residence times across models, which has implications for the response of ecosystems and global carbon cycling to perturbations. Given this large uncertainty, iron fertilization experiments based on any single current generation model should be interpreted with caution. Improvements to how such models represent iron scavenging and also biological cycling are needed to raise confidence in their projections of global biogeochemical change in the ocean. specialized iron ocean biogeochemistry climate model MONDE 032 020 30 2 149-174 2016 0886-6236 https://www.documentation.ird.fr/hor/fdi:010066717 10.1002/2015gb005289 0886-6236 [F B010066717] https://www.documentation.ird.fr/hor/fdi:010066717 https://www.documentation.ird.fr/intranet/publi/2016/04/010066717.pdf Accès réservé (Intranet de l'IRD) IRD - Base Horizon / Pleins textes 2016-05-03 2021-09-11 fdi:010066717 fre