Simple jQuery Dropdowns
Please use this identifier to cite or link to this item:
Full metadata record
DC FieldValueLanguage
dc.contributor.authorJ. Charpentieren_US
dc.contributor.authorL. Fariasen_US
dc.contributor.authorN. Yoshidaen_US
dc.contributor.authorN. Boontanonen_US
dc.contributor.authorP. Raimbaulten_US
dc.contributor.otherUniversity of Concepcionen_US
dc.contributor.otherTokyo Institute of Technologyen_US
dc.contributor.otherJapan Science and Technology Agencyen_US
dc.contributor.otherFaculty of Environment and Resource Studies, Mahidol Universityen_US
dc.contributor.otherInstitut Mediterraneen dOceanologieen_US
dc.identifier.citationBiogeosciences. Vol.4, No.5 (2007), 729-741en_US
dc.description.abstractThe mechanisms of microbial nitrous oxide (N2O) production in the ocean have been the subject of many discussions in recent years. New isotopomeric tools can further refine our knowledge of N2O sources in natural environments. This study compares hydrographic, N2O concentration, and N2O isotopic and isotopomeric data from three stations along a coast-perpendicular transect in the South Pacific Ocean, extending from the center (Sts. GYR and EGY) of the subtropical oligotrophic gyre (∼26° S; 114° W) to the upwelling zone (St. UPX) off the central Chilean coast (∼34° S). Although AOUZ/N2O and NO3-trends support the idea that most of the N2O (mainly from intermediate water (200-600 m)) comes from nitrification, N2O isotopomeric composition (intramolecular distribution of15N isotopes) expressed as SP (site preference of15N) shows low values (10 to 12‰) that could be attributed to the production through of microbial nitrifier denitrification (reduction of nitrite to N2O mediated by ammonium oxidizers). The coincidence of this SP signal with high - stability layer, where sinking organic particles can accumulate, suggests that N2O could be produced by nitrifier denitrification inside particles. It is postulated that deceleration of particles in the pycnocline can modify the advection - diffusion balance inside particles, allowing the accumulation of nitrite and O2depletion suitable for nitrifier denitrication. As lateral advection seems to be relatively insignificant in the gyre, in situ nitrifier denitrification could account for 40-50% of the N2O produced in this layer. In contrast, coastal upwelling system is characterized by O2deficient condition and some N deficit in a eutrophic system. Here, N2O accumulates up to 480% saturation, and isotopic and isotopomer signals show highly complex N2O production processes, which presumably reflect both the effect of nitrification and denitrification at low O2levels on N2O production, but net N2O consumption by denitrification was not observed.en_US
dc.rightsMahidol Universityen_US
dc.subjectAgricultural and Biological Sciencesen_US
dc.subjectEarth and Planetary Sciencesen_US
dc.titleNitrous oxide distribution and its origin in the central and eastern South Pacific Subtropical Gyreen_US
Appears in Collections:Scopus 2006-2010

Files in This Item:
There are no files associated with this item.

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.