2011/02/01 by Stephanie Henson, Richard Sanders, Esben Madsen +3 · 5 citations
Earth and Planetary Sciences · Environmental Science · #Marine and coastal ecosystems #Atmospheric and Environmental Gas Dynamics #Ocean Acidification Effects and Responses
paper · pdf · doi:10.1029/2011gl046735
openalex publication_date 2011/02/01 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/01
[1] A major term in the global carbon cycle is the ocean's biological carbon pump which is dominated by sinking of small organic particles from the surface ocean to its interior. Several different approaches to estimating the magnitude of the pump have been used, yielding a large range of estimates. Here, we use an alternative methodology, a thorium isotope tracer, that provides direct estimates of particulate organic carbon export. A large database of thorium-derived export measurements was compiled and extrapolated to the global scale by correlation with satellite sea surface temperature fields. Our estimates of export efficiency are significantly lower than those derived from the f-ratio, and we estimate global integrated carbon export as ∼5 GtC yr−1, lower than most current estimates. The lack of consensus amongst different methodologies on the strength of the biological carbon pump emphasises that our knowledge of a major planetary carbon flux remains incomplete.