nerc.ac.uk

Attenuation of sinking particulate organic carbon flux through the mesopelagic

Marsay, Chris M.; Sanders, Richard J.; Henson, Stephanie A.; Pabortsava, Katsiaryna; Achterberg, Eric P.; Lampitt, Richard S.. 2015 Attenuation of sinking particulate organic carbon flux through the mesopelagic. Proceedings of the National Academy of Science, 112 (4). 1089-1094. 10.1073/pnas.1415311112

Before downloading, please read NORA policies.
[img]
Preview
Text
1089.full.pdf

Download (1MB) | Preview

Abstract/Summary

The biological carbon pump, which transports particulate organic carbon (POC) from the surface to the deep ocean, plays an important role in regulating atmospheric carbon dioxide (CO2) concentrations. We know very little about geographical variability in the remineralization depth of this sinking material and less about what controls such variability. Here we present previously unpublished profiles of mesopelagic POC flux derived from neutrally buoyant sediment traps deployed in the North Atlantic, from which we calculate the remineralization length scale for each site. Combining these results with corresponding data from the North Pacific, we show that the observed variability in attenuation of vertical POC flux can largely be explained by temperature, with shallower remineralization occurring in warmer waters. This is seemingly inconsistent with conclusions drawn from earlier analyses of deep-sea sediment trap and export flux data, which suggest lowest transfer efficiency at high latitudes. However, the two patterns can be reconciled by considering relatively intense remineralization of a labile fraction of material in warm waters, followed by efficient downward transfer of the remaining refractory fraction, while in cold environments, a larger labile fraction undergoes slower remineralization that continues over a longer length scale. Based on the observed relationship, future increases in ocean temperature will likely lead to shallower remineralization of POC and hence reduced storage of CO2 by the ocean.

Item Type: Publication - Article
Digital Object Identifier (DOI): 10.1073/pnas.1415311112
Additional Keywords: biological carbon pump, particulate organic carbon, remineralization, mesopelagic
NORA Subject Terms: Marine Sciences
Date made live: 15 Dec 2014 13:13 +0 (UTC)
URI: http://nora.nerc.ac.uk/id/eprint/509087

Actions (login required)

View Item View Item

Document Downloads

Downloads for past 30 days

Downloads per month over past year

More statistics for this item...