Data_Sheet_1_Marine CO2 Patterns in the Northern Salish Sea.docx

• Main Authors: Wiley Evans, Katie Pocock, Alex Hare, Carrie Weekes, Burke Hales, Jennifer Jackson, Helen Gurney-Smith, Jeremy T. Mathis, Simone R. Alin, Richard A. Feely
• Format: Dataset
• Language: unknown
• Published: 2019
• Subjects: Oceanography; Marine Biology; Marine Geoscience; Biological Oceanography; Chemical Oceanography; Physical Oceanography; Marine Engineering; ocean acidification; coastal CO2 chemistry; aragonite saturation state; anthropogenic CO2; long-term assessment; Canada; British Columbia; Ocean acidification
• Online Access: https://doi.org/10.3389/fmars.2018.00536.s001; https://figshare.com/articles/Data_Sheet_1_Marine_CO2_Patterns_in_the_Northern_Salish_Sea_docx/7586765

Marine carbon dioxide (CO 2 ) system data has been collected from December 2014 to June 2018 in the Northern Salish Sea (NSS; British Columbia, Canada) and consisted of continuous measurements at two sites as well as spatially- and seasonally distributed discrete seawater samples. The array of CO 2 observing activities included high-resolution CO 2 partial pressure (pCO 2 ) and pH T (total scale) measurements made at the Hakai Institute’s Quadra Island Field Station (QIFS) and from an Environment Canada weather buoy, respectively, as well as discrete seawater measurements of pCO 2 and total dissolved inorganic carbon (TCO 2 ) obtained during a number of field campaigns. A relationship between NSS alkalinity and salinity was developed with the discrete datasets and used with the continuous measurements to highly resolve the marine CO 2 system. Collectively, these datasets provided insights into the seasonality in this historically under-sampled region and detail the area’s tendency for aragonite saturation state (Ω arag ) to be at non-corrosive levels (i.e., Ω arag > 1) only in the upper water column during spring and summer months. This depth zone and time period of reprieve can be periodically interrupted by strong northwesterly winds that drive short-lived (∼1 week) episodes of high-pCO 2 , low-pH, and low-Ω arag conditions throughout the region. Interannual variability in summertime conditions was evident and linked to reduced northwesterly winds and increased stratification. Anthropogenic CO 2 in NSS surface water was estimated using data from 2017 combined with the global atmospheric CO 2 forcing for the period 1765 to 2100, and projected a mean value of 49 ± 5 μmol kg -1 for 2018. The estimated trend in anthropogenic CO 2 was further used to assess the evolution of Ω arag and pH T levels in NSS surface water, and revealed that wintertime corrosive Ω arag conditions were likely absent pre-1900. The percent of the year spent above Ω arag = 1 has dropped from ∼98% in 1900 to ∼60% by 2018. Over the coming ...