136058 - Highly variable iron content modulates iceberg-ocean fertilisation.pdf (1.67 MB)
Highly variable iron content modulates iceberg-ocean fertilisation and potential carbon export
journal contribution
posted on 2023-05-20, 08:37 authored by Hopwood, MJ, Carroll, D, Hofer, J, Achterberg, EP, Meire, L, Le Moigne, FAC, Lennart BachLennart Bach, Eich, C, Sutherland, DA, Gonzalez, HEMarine phytoplankton growth at high latitudes is extensively limited by iron availability. Icebergs are a vector transporting the bioessential micronutrient iron into polar oceans. Therefore, increasing iceberg fluxes due to global warming have the potential to increase marine productivity and carbon export, creating a negative climate feedback. However, the magnitude of the iceberg iron flux, the subsequent fertilization effect and the resultant carbon export have not been quantified. Using a global analysis of iceberg samples, we reveal that iceberg iron concentrations vary over 6 orders of magnitude. Our results demonstrate that, whilst icebergs are the largest source of iron to the polar oceans, the heterogeneous iron distribution within ice moderates iron delivery to offshore waters and likely also affects the subsequent ocean iron enrichment. Future marine productivity may therefore be not only sensitive to increasing total iceberg fluxes, but also to changing iceberg properties, internal sediment distribution and melt dynamics.
History
Publication title
Nature CommunicationsVolume
10Article number
5261Number
5261Pagination
1-10ISSN
2041-1723Department/School
Institute for Marine and Antarctic StudiesPublisher
Nature Publishing GroupPlace of publication
United KingdomRights statement
Copyright 2019 The Authors. Licensed under Creative Commons Attribution 4.0 International (CC BY 4.0) https://creativecommons.org/licenses/by/4.0/Repository Status
- Open