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Hydrothermal (NN)-N-15-N-15 abundances constrain the origins of mantle nitrogen 期刊论文
NATURE, 2020, 580 (7803) : 367-+
作者:  Zhao, Steven;  Jang, Cholsoon;  Liu, Joyce;  Uehara, Kahealani;  Gilbert, Michael;  Izzo, Luke;  Zeng, Xianfeng;  Trefely, Sophie;  Fernandez, Sully;  Carrer, Alessandro;  Miller, Katelyn D.;  Schug, Zachary T.;  Snyder, Nathaniel W.;  Gade, Terence P.;  Titchenell, Paul M.;  Rabinowitz, Joshua D.;  Wellen, Kathryn E.
收藏  |  浏览/下载:34/0  |  提交时间:2020/05/13

Nitrogen is the main constituent of the Earth'  s atmosphere, but its provenance in the Earth'  s mantle remains uncertain. The relative contribution of primordial nitrogen inherited during the Earth'  s accretion versus that subducted from the Earth'  s surface is unclear(1-6). Here we show that the mantle may have retained remnants of such primordial nitrogen. We use the rare (NN)-N-15-N-15 isotopologue of N-2 as a new tracer of air contamination in volcanic gas effusions. By constraining air contamination in gases from Iceland, Eifel (Germany) and Yellowstone (USA), we derive estimates of mantle delta N-15 (the fractional difference in N-15/N-14 from air), N-2/Ar-36 and N-2/He-3. Our results show that negative delta N-15 values observed in gases, previously regarded as indicating a mantle origin for nitrogen(7-10), in fact represent dominantly air-derived N-2 that experienced N-15/N-14 fractionation in hydrothermal systems. Using two-component mixing models to correct for this effect, the (NN)-N-15-N-15 data allow extrapolations that characterize mantle endmember delta N-15, N-2/Ar-36 and N-2/He-3 values. We show that the Eifel region has slightly increased delta N-15 and N-2/Ar-36 values relative to estimates for the convective mantle provided by mid-ocean-ridge basalts(11), consistent with subducted nitrogen being added to the mantle source. In contrast, we find that whereas the Yellowstone plume has delta N-15 values substantially greater than that of the convective mantle, resembling surface components(12-15), its N-2/Ar-36 and N-2/He-3 ratios are indistinguishable from those of the convective mantle. This observation raises the possibility that the plume hosts a primordial component. We provide a test of the subduction hypothesis with a two-box model, describing the evolution of mantle and surface nitrogen through geological time. We show that the effect of subduction on the deep nitrogen cycle may be less important than has been suggested by previous investigations. We propose instead that high mid-ocean-ridge basalt and plume delta N-15 values may both be dominantly primordial features.


  
Benefits of Explicit Treatment of Zero Flows in Probabilistic Hydrological Modeling of Ephemeral Catchments 期刊论文
WATER RESOURCES RESEARCH, 2019, 55 (12) : 11035-11060
作者:  McInerney, David;  Kavetski, Dmitri;  Thyer, Mark;  Lerat, Julien;  Kuczera, George
收藏  |  浏览/下载:19/0  |  提交时间:2020/02/16
probabilistic streamflow prediction  ephemeral catchments  residual error model  zero flow  censoring approach  Box-Cox transformation  
Expanded comfort assessment in outdoor urban public spaces using Box-Cox transformation 期刊论文
LANDSCAPE AND URBAN PLANNING, 2019, 190
作者:  Peng, Y.;  Feng, T.;  Timmermans, H. J. P.
收藏  |  浏览/下载:15/0  |  提交时间:2019/11/27
Outdoor comfort  Expanded model  Non-linear model  Box-Cox transformation  
Statistical Postprocessing of Water Level Forecasts Using Bayesian Model Averaging With Doubly Truncated Normal Components 期刊论文
WATER RESOURCES RESEARCH, 2019, 55 (5) : 3997-4013
作者:  Baran, Sandor;  Hemri, Stephan;  El Ayari, Mehrez
收藏  |  浏览/下载:22/0  |  提交时间:2019/11/26
Bayesian model averaging  Box-Cox transformation  ensemble model output statistics  ensemble postprocessing  probabilistic forecasting  truncated normal distribution  
Heterogeneous N2O5 Uptake During Winter: Aircraft Measurements During the 2015 WINTER Campaign and Critical Evaluation of Current Parameterizations 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2018, 123 (8) : 4345-4372
作者:  McDuffie, Erin E.;  Fibiger, Dorothy L.;  Dube, William P.;  Lopez-Hilfiker, Felipe;  Lee, Ben H.;  Thornton, Joel A.;  Shah, Viral;  Jaegle, Lyatt;  Guo, Hongyu;  Weber, Rodney J.;  Reeves, J. Michael;  Weinheimer, Andrew J.;  Schroder, Jason C.;  Campuzano-Jost, Pedro;  Jimenez, Jose L.;  Dibb, Jack E.;  Veres, Patrick;  Ebben, Carly;  Sparks, Tamara L.;  Wooldridge, Paul J.;  Cohen, Ronald C.;  Hornbrook, Rebecca S.;  Apel, Eric C.;  Campos, Teresa;  Hall, Samuel R.;  Ullmann, Kirk;  Brown, Steven S.
收藏  |  浏览/下载:23/0  |  提交时间:2019/04/09
heterogeneous uptake  WINTER  uptake parameterizations  box model  N2O5  
Radical budget and ozone chemistry during autumn in the atmosphere of an urban site in central China 期刊论文
JOURNAL OF GEOPHYSICAL RESEARCH-ATMOSPHERES, 2017, 122 (6)
作者:  Lu, Xingcheng;  Chen, Nan;  Wang, Yuhang;  Cao, Wenxiang;  Zhu, Bo;  Yao, Teng;  Fung, Jimmy C. H.;  Lau, Alexis K. H.
收藏  |  浏览/下载:10/0  |  提交时间:2019/04/09
ROx  O-3  0-D box model  HONO  agricultural burning