The northwest (NW) North Atlantic, including the Labrador Sea, is critical for understanding the global ocean’s changing biogeochemistry. Deep convection in the Labrador Sea is a major pathway for supplying oxygen to the ocean’s interior and sequestering anthropogenic carbon dioxide but is highly sensitive to climate-induced changes.
An accurate quantification of the NW North Atlantic’s primary production and carbon sink as well as their variability and responses to a warming climate are urgent scientific challenges, but presently hampered by insufficient biogeochemical observations.
The recent maturation of autonomous platforms and miniaturized sensors makes it feasible, for the first time, to collect sustained and cost-effective measurements of physical and biogeochemical ocean properties as they vary in 3-dimensional space.
For the past two decades, Argo has maintained a global array of almost 4,000 profiling floats that measure temperature and salinity (T&S) in the upper 2,000 m of the ocean. Argo floats are free-drifting, battery-powered profiling devices, capable of adjusting their buoyancy through an internal bladder with pump. They carry miniaturized sensors and relay their measurements in real time via satellite telemetry.
Capitalizing on this success and recent advances in BGC sensor technology, the addition of such sensors to the Argo program is now ongoing.
A BGC Argo array for the NW North Atlantic has been proposed that includes 32 standard BGC floats measuring six BGC properties (oxygen, nitrate, pH, suspended particles, chlorophyll, and light) in addition to T&S and 10 process floats with fewer sensors for more rapid sampling.
By providing a broad suite of observations with unprecedented spatial and temporal coverage, and by integrating these into biogeochemical models and data products, the proposed program will enable quantification of primary production, carbon uptake and export, ocean ventilation, and acidification in this globally important region, and will deliver real-time ocean data and a range of data products tailored to different end-user needs.