Ventilation time scales of the North Atlantic subtropical cell revealed by coral radiocarbon from the Cape Verde Islands

摘要: We present coral- and sclerosponge-based reconstructions of the 14C content in North Atlantic dissolved inorganic carbon (DIC) during last ~100 years from subtropical cells (STCs). These waters are sensitive to dynamics shallow overturning meridional circulation that transports heat water masses subtropics tropics. use these records investigate patterns off-equatorial upwelling regions STCs, which not well understood. Coral sclerosponge skeletons provide long time series ocean DIC content, a tracer oceanic circulation, effectively extending observational record back time. Sclerosponge data Bahamas were used extend existing 21st century. Cape Verde Islands (1890–2002) captured signature brought surface STC near West African coast. observe unique postbomb trend at is similar Pacific, we interpret this as result slow penetration bomb into interior part circulation. Using multibox mixing model constrain history eastern tropical Atlantic, estimate 20 year scale for ventilation thermocline area ocean. The similarity between Pacific 14C-based suggests both caused by rather than more complex explanations invoke changes depth (e.g., related El Nino–Southern Oscillation variability) or strength cells. Our results offer constraints models anthropogenic CO2 uptake attempt reproduce characteristics wind-driven Atlantic.