Data_Sheet_1_The Influence of Water Mass Mixing and Particle Dissolution on the Silicon Cycle in the Central Arctic Ocean.pdf

• Main Authors: Bianca T. P. Liguori, Claudia Ehlert, Katharina Pahnke
• Format: Dataset
• Language: unknown
• Published: 2020
• Subjects: Oceanography; Marine Biology; Marine Geoscience; Biological Oceanography; Chemical Oceanography; Physical Oceanography; Marine Engineering; silicon isotopes; dissolved silicon; biogenic silica; Eurasian Basin; shelf input; optimum multiparameter analysis; GEOTRACES; Arctic; Arctic Ocean; Fram Strait; North Atlantic
• Online Access: https://doi.org/10.3389/fmars.2020.00202.s001; https://figshare.com/articles/Data_Sheet_1_The_Influence_of_Water_Mass_Mixing_and_Particle_Dissolution_on_the_Silicon_Cycle_in_the_Central_Arctic_Ocean_pdf/12089961

The use of the silicon isotope composition of dissolved silicon (δ 30 Si-DSi) to understand the marine silicon cycle has been increasing in recent years. Here we present δ 30 Si-DSi and δ 30 Si of biogenic silica (δ 30 Si-bSiO 2 ) in the intermediate to deep waters of the Central Arctic Ocean (AO) aiming at investigating in more detail the relative influence of water mass mixing and particle flux on the Si cycle in the AO. Comparing the δ 30 Si-DSi with the water mass composition derived from Optimum Multiparameter (OMP) analysis, we were able to test the influence of the water masses in the δ 30 Si-DSi distribution. We were able to show the dominant Atlantic Water (AW) influence at the stations close to the Fram Strait (station 32 and 40, δ 30 Si-DSi = 1.51 ± 0.11‰, 2SEM, n = 3) and the only small δ 30 Si-DSi modification when compared to the endmember value from a previous study (δ 30 Si-DSi = 1.55‰). The Dense Arctic Atlantic Water, dominating from 200 to 500 m water depth (except for stations 32 and 40, where it was present only at 500 m), was marked by heavier δ 30 Si-DSi of 1.62 ± 0.06‰ (2SEM, n = 21). This is probably due to the influence of entraining equally dense water from the shelves. Due to productivity and Si utilization on the shelves, both water and bSiO 2 , that were transported laterally into the Central AO, were characterized by higher δ 30 Si, with δ 30 Si-bSiO 2 of 1.64 ± 0.13‰ (2SEM, n = 7). Particle dissolution at greater depths did not play a major role in the δ 30 Si-DSi of deep waters due to the low bSiO 2 concentrations at these greater depths. Outflowing water masses from the AO present different δ 30 Si-DSi, with lower values around 1.46‰ originating from the Central AO influencing predominantly DSOW and ISOW, and higher values around 2‰ originating from the Canadian AO influencing predominantly LSW. Those signatures correspond with the δ 30 Si-DSi found in the North Atlantic. Consequently, the AO potentially presents several isotopically different endmembers that contribute to the ...