Consistency of cruise data of the CARINA database in the Atlantic sector of the Southern Ocean

[摘要] Initially a North Atlantic project, the CARINA carbon synthesis was extendedto include the Southern Ocean. Carbon and relevant hydrographic andgeochemical ancillary data from cruises all across the Arctic MediterraneanSeas, Atlantic and Southern Ocean were released to the public and mergedinto a new database as part of the CARINA synthesis effort. Of a total of188 cruises, 37 cruises are part of the Southern Ocean, including 11 fromthe Atlantic sector. The variables from all Southern Ocean cruises,including dissolved inorganic carbon (TCO₂), total alkalinity, oxygen,nitrate, phosphate and silicate, were examined for cruise-to-cruiseconsistency in one collective effort. Seawater pH and chlorofluorocarbons(CFCs) are also part of the database, but the pH quality control (QC) isdescribed in another Earth System Science Data publication, while thecomplexity of the Southern Ocean physics and biogeochemistry prevented aproper QC analysis of the CFCs. The area-specific procedures of qualitycontrol, including crossover analysis between stations and inversionanalysis of all crossover data (i.e. secondary QC), are briefly describedhere for the Atlantic sector of the Southern Ocean. Data from an existing,quality controlled database (GLODAP) were used as a reference for ourcomputations – however, the reference data were included into the analysiswithout applying the recommended GLODAP adjustments so the corrections couldbe independently verified. The outcome of this effort is an internallyconsistent, high-quality carbon data set for all cruises, including thereference cruises. The suggested corrections by the inversion analysis wereallowed to vary within a fixed envelope, thus accounting for naturalvariability. The percentage of cruises adjusted ranged from 31% (fornitrate) to 54% (for phosphate) depending on the variable.

[学科分类] 天文学(综合)