Coupling of oceanic carbon and nitrogen facilitates spatially resolved quantitative reconstruction of nitrate inventories.
Nat Commun
; 9(1): 1217, 2018 03 23.
Article
em En
| MEDLINE
| ID: mdl-29572447
ABSTRACT
Anthropogenic impacts are perturbing the global nitrogen cycle via warming effects and pollutant sources such as chemical fertilizers and burning of fossil fuels. Understanding controls on past nitrogen inventories might improve predictions for future global biogeochemical cycling. Here we show the quantitative reconstruction of deglacial bottom water nitrate concentrations from intermediate depths of the Peruvian upwelling region, using foraminiferal pore density. Deglacial nitrate concentrations correlate strongly with downcore δ13C, consistent with modern water column observations in the intermediate Pacific, facilitating the use of δ13C records as a paleo-nitrate-proxy at intermediate depths and suggesting that the carbon and nitrogen cycles were closely coupled throughout the last deglaciation in the Peruvian upwelling region. Combining the pore density and intermediate Pacific δ13C records shows an elevated nitrate inventory of >10% during the Last Glacial Maximum relative to the Holocene, consistent with a δ13C-based and δ15N-based 3D ocean biogeochemical model and previous box modeling studies.
Texto completo:
1
Coleções:
01-internacional
Base de dados:
MEDLINE
Tipo de estudo:
Prognostic_studies
Idioma:
En
Revista:
Nat Commun
Ano de publicação:
2018
Tipo de documento:
Article