Synthesis Product for Ocean Time Series (SPOTS) – a ship-based biogeochemical pilot

• Published in: Earth System Science Data
• Main Authors: Lange, Nico, Fiedler, Björn, Álvarez, Marta, Benoit-Cattin, Alice, Benway, Heather, Buttigieg, Pier Luigi, Coppola, Laurent, Currie, Kim, Flecha, Susana, Gerlach, Dana S., Honda, Makio, Huertas, I. Emma, Lauvset, Siv K., Muller-Karger, Frank, Körtzinger, Arne, O'Brien, Kevin M., Ólafsdóttir, Sólveig R., Pacheco, Fernando C., Rueda-Roa, Digna, Skjelvan, Ingunn, Wakita, Masahide, White, Angelicque, Tanhua, Toste
• Format: Text
• Language: English
• Published: 2024
• Subjects: Nordic Seas
• Online Access: https://doi.org/10.5194/essd-16-1901-2024; https://essd.copernicus.org/articles/16/1901/2024/

The presented pilot for the Synthesis Product for Ocean Time Series (SPOTS) includes data from 12 fixed ship-based time-series programs. The related stations represent unique open-ocean and coastal marine environments within the Atlantic Ocean, Pacific Ocean, Mediterranean Sea, Nordic Seas, and Caribbean Sea. The focus of the pilot has been placed on biogeochemical essential ocean variables: dissolved oxygen, dissolved inorganic nutrients, inorganic carbon (pH, total alkalinity, dissolved inorganic carbon, and partial pressure of CO 2 ), particulate matter, and dissolved organic carbon. The time series used include a variety of temporal resolutions (monthly, seasonal, or irregular), time ranges (10–36 years), and bottom depths (80–6000 m), with the oldest samples dating back to 1983 and the most recent one corresponding to 2021. Besides having been harmonized into the same format (semantics, ancillary data, units), the data were subjected to a qualitative assessment in which the applied methods were evaluated and categorized. The most recently applied methods of the time-series programs usually follow the recommendations outlined by the Bermuda Time Series Workshop report (Lorenzoni and Benway, 2013), which is used as the main reference for “method recommendations by prevalent initiatives in the field”. However, measurements of dissolved oxygen and pH, in particular, still show room for improvement. Additional data quality descriptors include precision and accuracy estimates, indicators for data variability, and offsets compared to a reference and widely recognized data product for the global ocean: the GLobal Ocean Data Analysis Project (GLODAP). Generally, these descriptors indicate a high level of continuity in measurement quality within time-series programs and a good consistency with the GLODAP data product, even though robust comparisons to the latter are limited. The data are available as (i) a merged comma-separated file that is compliant with the World Ocean Circulation Experiment (WOCE) exchange format ...