Nitrous oxide production by nitrification and denitrification in the Eastern Tropical South Pacific oxygen minimum zone

Qixing Ji, Andrew R. Babbin, Amal Jayakumar, Sergey Oleynik, Bess B. Ward

Research output: Contribution to journalArticle

49 Scopus citations

Abstract

The Eastern Tropical South Pacific oxygen minimum zone (ETSP-OMZ) is a site of intense nitrous oxide (N2O) flux to the atmosphere. This flux results from production of N2O by nitrification and denitrification, but the contribution of the two processes is unknown. The rates of these pathways and their distributions were measured directly using 15N tracers. The highest N2O production rates occurred at the depth of peak N2O concentrations at the oxic-anoxic interface above the oxygen deficient zone (ODZ) because slightly oxygenated waters allowed (1) N2O production from both nitrification and denitrification and (2) higher nitrous oxide production yields from nitrification. Within the ODZ proper (i.e., anoxia), the only source of N2O was denitrification (i.e., nitrite and nitrate reduction), the rates of which were reflected in the abundance of nirS genes (encoding nitrite reductase). Overall, denitrification was the dominant pathway contributing the N2O production in the ETSP-OMZ.

Original languageEnglish (US)
Pages (from-to)10755-10764
Number of pages10
JournalGeophysical Research Letters
Volume42
Issue number24
DOIs
StatePublished - Dec 28 2015

All Science Journal Classification (ASJC) codes

  • Geophysics
  • Earth and Planetary Sciences(all)

Keywords

  • denitrification
  • nitrification
  • nitrous oxide
  • oxygen
  • oxygen minimum zone

Fingerprint Dive into the research topics of 'Nitrous oxide production by nitrification and denitrification in the Eastern Tropical South Pacific oxygen minimum zone'. Together they form a unique fingerprint.

  • Cite this