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On October 22, 2024, 8:28:31 PM UTC, Gravatar ckan_admin:

  • Updated description of Fe-binding ligands in Fram Strait and over the Northeast Greenland shelf - cruise PS100 from

    Here we investigate the potential sources, distribution, properties and transport of natural Fe-binding ligands in Fram Strait and over the Northeast Greenland shelf. Our results indicate that the main sources of organic ligands to surface waters of Fram Strait were Fe-binding ligands associated with primary productivity together with ligands from the Arctic Ocean. We calculated a total Fe-binding ligand concentration, [Lt], in Polar Surface Water from the western Fram Strait of 1.65±0.4 nM eq. Fe. This value is intermediate compared to the reported values for the Arctic and the North Atlantic Ocean, confirming the suggestion of a previous study that [Lt] decreases southward from the Arctic Ocean. The differences between ligand sources in different biogeochemical provinces, result in distinctive ligand properties and distributions that are reflected in [Lt], the binding strength (log K_(FeL,Fe')^cond) and the reactivity (log α_FeL) of the ligands. Higher [Lt] was present near the Nioghalvfjerdsfjorden (79N) glacier terminus and in the Westwind Trough (median of [Lt]=2.17 nM eq. Fe; log K_(FeL,Fe')^cond=12.3; log α_FeL =3.4) than in the Norske Trough (median of [Lt]=1.89 nM eq. Fe; log K_(FeL,Fe')^cond=12.8; log α_FeL =3.8) and in Fram Strait (median of [Lt]=1.38 nM eq. Fe; log K_(FeL,Fe')^cond=13; log α_FeL =3.9), but they were weaker and therefore less reactive. Our findings reveal the fundamental mechanism on how organic Fe-binding ligands determined dissolved-Fe (DFe) transport from the 79N glacier to Fram Strait. The lower ligand binding strength result in a higher inorganic Fe concentration, [Fe`], which is more prone to precipitation and/or scavenging than Fe complexed with ligands. Accordingly, a portion of the glacial DFe will not be transported over the shelf into the ocean, indicating that organic ligands are an important factor regulating DFe export. The ongoing changes in the Arctic and subarctic will influence the sources of Fe binding ligands and therefore have consequences for Fe solubility.
    to
    Here we investigate the potential sources, distribution, properties and transport of natural Fe-binding ligands in Fram Strait and over the Northeast Greenland shelf. Our results indicate that the main sources of organic ligands to surface waters of Fram Strait were Fe-binding ligands associated with primary productivity together with ligands from the Arctic Ocean. We calculated a total Fe-binding ligand concentration, [Lt], in Polar Surface Water from the western Fram Strait of 1.65??0.4 nM eq. Fe. This value is intermediate compared to the reported values for the Arctic and the North Atlantic Ocean, confirming the suggestion of a previous study that [Lt] decreases southward from the Arctic Ocean. The differences between ligand sources in different biogeochemical provinces, result in distinctive ligand properties and distributions that are reflected in [Lt], the binding strength (log K_(FeL,Fe')^cond) and the reactivity (log ??_FeL) of the ligands. Higher [Lt] was present near the Nioghalvfjerdsfjorden (79N) glacier terminus and in the Westwind Trough (median of [Lt]=2.17 nM eq. Fe; log K_(FeL,Fe')^cond=12.3; log ??_FeL =3.4) than in the Norske Trough (median of [Lt]=1.89 nM eq. Fe; log K_(FeL,Fe')^cond=12.8; log ??_FeL =3.8) and in Fram Strait (median of [Lt]=1.38 nM eq. Fe; log K_(FeL,Fe')^cond=13; log ??_FeL =3.9), but they were weaker and therefore less reactive. Our findings reveal the fundamental mechanism on how organic Fe-binding ligands determined dissolved-Fe (DFe) transport from the 79N glacier to Fram Strait. The lower ligand binding strength result in a higher inorganic Fe concentration, [Fe`], which is more prone to precipitation and/or scavenging than Fe complexed with ligands. Accordingly, a portion of the glacial DFe will not be transported over the shelf into the ocean, indicating that organic ligands are an important factor regulating DFe export. The ongoing changes in the Arctic and subarctic will influence the sources of Fe binding ligands and therefore have consequences for Fe solubility.


  • Changed the version of Fe-binding ligands in Fram Strait and over the Northeast Greenland shelf - cruise PS100 to 2 (previously 1)