A Close Look at Dissolved Silica Dynamics in Disko Bay, West Greenland

Global Biogeochemical Cycles, Journal Year: 2025, Volume and Issue: 39(1)

Published: Jan. 1, 2025

Abstract Discharge of calved ice, runoff and mixing driven by subglacial discharge plumes likely have consequences for marine biogeochemistry in Disko Bay, which hosts the largest glacier northern hemisphere, Sermeq Kujalleq. Glacier retreat increasing may impact silica cycle because glaciers deliver elevated concentrations dissolved (dSi) compared to other macronutrients. However, annual flux dSi delivered ocean from Greenland Ice Sheet is poorly constrained difficulties distinguishing overlapping influence different sources. Here we constrain dynamics around including Ilulissat Icefjord four regions receiving with contrasting levels productivity turbidity. Both Si* ([dSi]‐[NO x − ]) indicated conservative two fjords land‐terminating glaciers, consistent results experiments. In three marine‐terminating macronutrient‐salinity distributions were strongly affected entrainment nutrients plumes. Entrainment saline waters explained 93 ± 51% enrichment outflowing plume Icefjord, whereas direct contribution freshwater was 0%–3%. Whilst not distinguished herein, minor regional sources include icebergs dissolution amorphous (aSi) either pelagic or benthic environments. Our suggest that supplemented as a source fluxes 0.25 0.67 Gmol yr −1 ∼1.9 year aSi dissolution.

Language: Английский

Insights into silicon cycling from ice sheet to coastal ocean from isotope geochemistry

Communications Earth & Environment, Journal Year: 2025, Volume and Issue: 6(1)

Published: April 19, 2025

Language: Английский