Publication Date:
2022-05-25
Description:
Author Posting. © American Geophysical Union, 2017. This article is posted here by permission of American Geophysical Union for personal use, not for redistribution. The definitive version was published in Global Biogeochemical Cycles 31 (2017): 1066–1088, doi:10.1002/2016GB005488.
Description:
In situ oxygen tracers (triple oxygen isotope and oxygen/argon ratios) were used to evaluate meridional trends in surface biological production and export efficiency across ~8000 km of the tropical and subtropical South Atlantic in March–May 2013. We used observations of picophytoplankton, nanophytoplankton, and microphytoplankton to evaluate community structure and diversity and assessed the relationships of these characteristics with production, export efficiency, and particulate organic carbon (POC) fluxes. Rates of productivity were relatively uniform along most of the transect with net community production (NCP) between 0 and 10 mmol O2 m−2 d−1, gross primary production (GPP) between 40 and 100 mmol O2 m−2 d−1, and NCP/GPP, a measure of export efficiency, ranging from 0.1 to 0.2 (0.05–0.1 in carbon units). However, notable exceptions to this basin-scale homogeneity included two locations with highly enhanced NCP and export efficiency compared to surrounding regions. Export of POC and particulate nitrogen, derived from sediment traps, correlated with GPP across the transect, over which the surface community was dominated numerically by picophytoplankton. NCP, however, did not correlate with POC flux; the mean difference between NCP and POC flux was similar to published estimates of dissolved organic carbon export from the surface ocean. The interrelated rates of production presented in this work contribute to the understanding, building on the framework of better-studied ocean basins, of how carbon is biologically transported between the atmosphere and the deep ocean.
Description:
National Science Foundation (NSF) Grant Number: OCE 1029676;
Gordon and Betty Moore Foundation Grant Grant Number: 537.01;
Woods Hole Oceanographic Institution (WHOI);
WHOI Devonshire Postdoctoral Scholarship;
National Defense Science and Engineering Graduate Fellowship;
WHOI Ocean Life Institute;
Woods Hole Oceanographic Institution (WHOI) Ocean and Climate Change Institute
NSF Grant Numbers: OCE 1029676, OCE 1154320
Description:
2018-01-11
Keywords:
Oxygen
;
Net community production
;
Gross primary production
;
Carbon flux
;
Triple oxygen isotopes
;
Argon
Repository Name:
Woods Hole Open Access Server
Type:
Article
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