Deep ocean nutrients imply large latitudinal variation in particle transfer efficiency

作者：Weber Thomas; Cram Jacob A; Leung Shirley W; DeVries Timothy; Deutsch Curtis

来源：Proceedings of the National Academy of Sciences, 2016, 113(31): 8606-8611.

DOI：10.1073/pnas.1604414113

• biological pump
• organic particles
• remineralization
• transfer efficiency
• ocean carbon storage

The "transfer efficiency" of sinking organic particles through the mesopelagic zone and into the deep ocean is a critical determinant of the atmosphere-ocean partition of carbon dioxide (CO2). Our ability to detect large-scale spatial variations in transfer efficiency is limited by the scarcity and uncertainties of particle flux data. Here we reconstruct deep ocean particle fluxes by diagnosing the rate of nutrient accumulation along transport pathways in a data-constrained ocean circulation model. Combined with estimates of organic matter export from the surface, these diagnosed fluxes reveal a global pattern of transfer efficiency to 1,000m that is high (similar to 25%) at high latitudes and low (similar to 5%) in subtropical gyres, with intermediate values in the tropics. This pattern is well correlated with spatial variations in phytoplankton community structure and the export of ballast minerals, which control the size and density of sinking particles. These findings accentuate the importance of high-latitude oceans in sequestering carbon over long timescales, and highlight potential impacts on remineralization depth as phytoplankton communities respond to a warming climate.

• 出版日期2016-8-2