Seawater carbonate chemistry and mass fluxes and elemental composition of particulate export in KOSMOS mesocosm experiments (2010-2014) ...

• Main Authors: Taucher, Jan, Bach, Lennart Thomas, Prowe, Friederike, Boxhammer, Tim, Kvale, Karin F, Riebesell, Ulf
• Format: Dataset
• Language: English
• Published: PANGAEA 2022
• Subjects: Arctic; Biomass/Abundance/Elemental composition; Coast and continental shelf; Entire community; Field experiment; Mesocosm or benthocosm; North Atlantic; Pelagos; Polar; Temperate; Event label; Type; Area/locality; DATE/TIME; Day of experiment; Treatment partial pressure of carbon dioxide; Biogenic silica, flux per day; Nitrogen, organic, particulate, flux per day; Carbon, organic, particulate, flux per day; Silicon/Nitrogen flux ratio; Carbon/Nitrogen flux ratio; Silicon/Carbon flux ratio; Salinity; Temperature, water; Alkalinity, total; Carbon, inorganic, dissolved; pH; Silicate; Phosphate; Carbonate system computation flag; Carbon dioxide; Fugacity of carbon dioxide water at sea surface temperature wet air; Partial pressure of carbon dioxide water at sea surface temperature wet air; Bicarbonate ion; Carbonate ion; Aragonite saturation state; Calcite saturation state; Mesocosm experiment; Measured spectrophotometrically after alkaline leaching of particulate matter; Elemental analyzer; Calculated using seacarb after Nisumaa et al. 2010; KOSMOS 2013; KOSMOS_2014; Ocean Acidification International Coordination Centre OA-ICC; Ocean acidification
• Online Access: https://dx.doi.org/10.1594/pangaea.946304; https://doi.pangaea.de/10.1594/PANGAEA.946304

Diatoms account for up to 40% of marine primary production and require silicic acid to grow and build their opal shell. On the physiological and ecological level, diatoms are thought to be resistant to, or even benefit from, ocean acidification. Yet, global-scale responses and implications for biogeochemical cycles in the future ocean remain largely unknown. Here we conducted five in situ mesocosm experiments with natural plankton communities in different biomes and find that ocean acidification increases the elemental ratio of silicon (Si) to nitrogen (N) of sinking biogenic matter by 17 ± 6 per cent under pCO2 conditions projected for the year 2100. This shift in Si:N seems to be caused by slower chemical dissolution of silica at decreasing seawater pH. We test this finding with global sediment trap data, which confirm a widespread influence of pH on Si:N in the oceanic water column. Earth system model simulations show that a future pH-driven decrease in silica dissolution of sinking material reduces the ... : In order to allow full comparability with other ocean acidification data sets, the R package seacarb (Gattuso et al, 2021) was used to compute a complete and consistent set of carbonate system variables, as described by Nisumaa et al. (2010). In this dataset the original values were archived in addition with the recalculated parameters (see related PI). The date of carbonate chemistry calculation by seacarb is 2022-07-13. ...