Marian B. Westley

Learn More
[1] Although the oceans are a significant source of the greenhouse gas nitrous oxide (N2O) to the atmosphere, the magnitude and characteristics of this source are poorly constrained. We present here stable isotope and isotopomer (intramolecular distribution of N within the linear NNO molecule) results for N2O and oxygen stable isotopic data for dissolved O2(More)
[1] Nitrous oxide (N2O) is an important atmospheric greenhouse gas and is involved in stratospheric ozone depletion. Analysis of the isotopomer ratios of N2O (i.e., the intramolecular distribution of N within the linear NNO molecule and the conventional N and O isotope ratios) can elucidate the mechanisms of N2O production and destruction. We analyzed the(More)
Two alternative approaches for the calibration of the intramolecular nitrogen isotope distribution in nitrous oxide using isotope ratio mass spectrometry have yielded a difference in the 15N site preference (defined as the difference between the delta15N of the central and end position nitrogen in NNO) of tropospheric N2O of almost 30 per thousand. One(More)
The low-oxygen regions of the world’s oceans have been shown to be major sources of nitrous oxide, a trace gas in the atmosphere that contributes to both greenhouse warming and the destruction of stratospheric ozone. Nitrous oxide can be produced as a by-product of nitrification or an intermediate of denitrification; low oxygen conditions enhance the yield(More)
The east lobe of Lake Bonney, a permanently ice-covered lake in the McMurdo Dry Valleys, Antarctica, has a mid-depth maximum N2O concentration of 43.3 mmol N L21 (.700,000% saturation with respect to air), representing one of the highest concentrations reported for a natural aquatic system. d15N and d18O measurements indicate that this is the most(More)
[1] We analyzed N2O isotopomer ratios (distribution of isotopes within N2O molecules) in the eastern tropical North Pacific. The N2O isotopomer ratios indicate the contribution of denitrification in the oxygen minimum zone (OMZ, 600 m in depth) in the western North Pacific, which is not consistent with the widely accepted nitrification hypothesis. Our(More)
  • 1