Present day and end of century (2100) iron speciation in the surface ocean


The main component of this data set comprises calculated inorganic iron concentrations (Fe' = sum of iron hydroxide species). Inorganic iron is the most bioavailable chemical form of Fe in the ocean. Concentrations of Fe' were calculated according to two models, which we refer to as the discrete ligand model and the continuous binding site model. The discrete ligand model, which is currently applied to calculate Fe speciation in global biogeochemical models, combines dissolved Fe concentrations, conditional stability constants and ligand concentrations to obtain inorganic iron, whilst the continuous distribution model uses the NICA-Donnan model to obtain Fe'. The data supports the manuscript "Climate change decreases biologically available iron pool in the surface ocean." In this manuscript we use the continuous binding site model to show that surface ocean Fe' is sufficient for Fe-replete phytoplankton. We apply new estimates of Fe' to a simple phytoplankton growth model to show that both Fe' and relative growth rates will decrease under the high-end future climate scenario (SSP5-8.5) in all Fe-limited ocean regions, and will mitigate current projections of increased primary productivity in Fe-limited high latitudes regions such as the Southern Ocean. Overall, we demonstrate that Fe-binding site heterogeneity is critical for iron speciation, and must be considered when predicting the response of marine primary producers to ongoing changes in ocean chemistry.

Related Identifier References
Metadata Access
Creator Gledhill, Martha ORCID logo; Liu, Fengjie ORCID logo; Zhang, Qiong; Browning, Thomas J ORCID logo; Twining, Ben S; Buck, Kristen N; Kwiatkowski, Lester ORCID logo; Bowler, Chris ORCID logo; Achterberg, Eric Pieter
Publisher PANGAEA
Publication Year 2024
Funding Reference European Commission Crossref Funder ID 891418 Marie Curie: Iron speciation in the microenvironment surrounding phytoplankton cells and the consequences for Fe bioavailability; NERC independent research fellowship Crossref Funder ID NE/V01451X/1 Controls on iron availability to marine phytoplankton; Southern Marine Science and Engineering Guangdong Laboratory Crossref Funder ID SML2021SP204 Southern Marine Science and Engineering Guangdong Laboratory Independent Research grant
Rights Creative Commons Attribution 4.0 International;
OpenAccess true
Resource Type Dataset
Format text/tab-separated-values
Size 10 data points
Discipline Earth System Research