Large-scale distribution of Atlantic nitrogen fixation controlled by iron availability

摘要: Oceanic fixed-nitrogen concentrations are controlled by the balance between nitrogen fixation and denitrification1, 2, 3, 4. A number of factors, including iron limitation5, 6, 7, can restrict fixation, introducing potential for decoupling inputs losses2, 5, 8. Such could significantly affect oceanic inventory consequently biological component ocean carbon storage hence air–sea partitioning dioxide2, 8, 9. However, extent to which nutrients limit in global is uncertain. Here, we examined rates nutrient surface waters Atlantic Ocean along a north–south 10,000 km transect during October November 2005. We show that were markedly higher North compared with South Ocean. Across two basins, was positively correlated dissolved negatively phosphorus concentrations. conclude inter-basin differences supply rather than availability. Analysis content deep suggests fixed enters Deep Water. Our study thus supports suggestion influences fixation5, subsequent interactions circulation patterns contribute loss2, 4,