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North Atlantic production of nitrous oxide in the context of changing atmospheric levels
Author(s) -
Freing A.,
Wallace D. W. R.,
Tanhua T.,
Walter S.,
Bange H. W.
Publication year - 2009
Publication title -
global biogeochemical cycles
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.512
H-Index - 187
eISSN - 1944-9224
pISSN - 0886-6236
DOI - 10.1029/2009gb003472
Subject(s) - nitrification , nitrous oxide , context (archaeology) , decomposition , tracer , nitrogen , environmental science , water column , production (economics) , chemistry , new production , atmospheric sciences , environmental chemistry , oceanography , nutrient , geology , phytoplankton , physics , organic chemistry , economics , macroeconomics , paleontology , nuclear physics
We use transit time distributions calculated from tracer data together with in situ measurements of N 2 O to estimate the concentration of biologically produced N 2 O ([N 2 O] xs ) and N 2 O production rates in the central North Atlantic Ocean. Our approach to estimation of N 2 O production rates integrates the effects of potentially varying production and decomposition mechanisms along the transport path of a water mass. We find that previously used approaches overestimate the oceanic equilibrium N 2 O concentrations by 8–13% and thus underestimate the strength of N 2 O sources in large parts of the water column. Thus the quantitative characteristics of the [N 2 O] xs /AOU relationship used as an indicator of nitrification are distorted. We developed a new parameterization of N 2 O production during nitrification depending linearly on AOU and exponentially on temperature and depth, which can be applied to calculate N 2 O production due to nitrification in the entire ocean including oxygen minimum zones.