title: Nitrogen cycling. Rapid nitrous oxide cycling in the suboxic ocean.
abstract: Nitrous oxide (N2O) is a powerful greenhouse gas and a major cause of stratospheric ozone depletion, yet its sources and sinks remain poorly quantified in the oceans. We used isotope tracers to directly measure N2O reduction rates in the eastern tropical North Pacific. Because of incomplete denitrification, N2O cycling rates are an order of magnitude higher than predicted by current models in suboxic regions, and the spatial distribution suggests strong dependence on both organic carbon and dissolved oxygen concentrations. Furthermore, N2O turnover is 20 times higher than the net atmospheric efflux. The rapid rate of this cycling coupled to an expected expansion of suboxic ocean waters implies future increases in N2O emissions.
authors.affiliation: Department of Geosciences, Princeton University, Princeton, NJ 08544, USA. Department of Civil and Environmental Engineering, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. babbin@mit.edu.
authors.forename: Andrew R
authors.initials: AR
authors.lastname: Babbin
authors.affiliation: School of Oceanography, University of Washington, Seattle, WA 98105, USA.
authors.forename: Daniele
authors.initials: D
authors.lastname: Bianchi
authors.affiliation: Department of Geosciences, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Amal
authors.initials: A
authors.lastname: Jayakumar
authors.affiliation: Department of Geosciences, Princeton University, Princeton, NJ 08544, USA.
authors.forename: Bess B
authors.initials: BB
authors.lastname: Ward
mesh_terms: D000818:Animals; D017752:Greenhouse Effect; D058458:Nitrogen Cycle; D009609:Nitrous Oxide / Q000737:chemistry*; D009792:Oceans and Seas; D010084:Oxidation-Reduction; D010100:Oxygen / Q000737:chemistry; D012623:Seawater / Q000737:chemistry*
chemical_list: D009609:Nitrous Oxide; D010100:Oxygen