Spatial and temporal variations of aragonite saturation states in the surface waters of the Western Arctic Ocean from 2016 to 2018 (NCEI Accession 0241111)

This dataset consists of spatial and temporal variations of aragonite saturation states in the surface waters of the Western Arctic Ocean from 2016 to 2018. The dataset also includes measurements of surface water temperature, salinity, dissolved inorganic carbon (DIC) and total alkalinity (TA). The aragonite saturation state (Ωarag) was determined for the surface waters of the western Arctic Ocean over three years, from 2016 to 2018, in an investigation of the present state of acidification of its waters and the main factors controlling the spatial and temporal variations in the surface Ωarag. The study area was divided into the Chukchi marginal area (CMA) and the East Siberian marginal area (ESMA) along a longitude of 180°E. In the CMA, the surface Ωarag during the study period ranged from 0.86 to 1.77, with an average of 1.16, indicating near saturation with aragonite. In the ESMA, the surface Ωarag during the study period ranged from 1.01 to 2.21, with a higher average (1.59) than the CMA. The surface Ωarag of the CMA was mainly determined by the mixing of seawater and freshwater introduced from rivers and/or sea ice, whereas in the ESMA it was influenced by the mixing of seawater and freshwater but also biological production and lateral mixing. In the near future, most of the surface waters of the CMA will likely be undersaturated with aragonite, which will threaten the survival of calcareous organisms and may lead to their extinction from this area. However, in the ESMA, the relatively high rate of biological production will increase the surface Ωarag, thus delaying aragonite undersaturation of the surface water.