HAL will be down for maintenance from Friday, June 10 at 4pm through Monday, June 13 at 9am. More information
Skip to Main content Skip to Navigation
Journal articles

Interpretation of the nitrogen isotopic signal variations in the Mauritanian upwelling with a 2D physical-biogeochemical model

Abstract : A physical-biogeochemical model is used to simulate the evolution of the δ15N signal during the last glacial-interglacial transition in sedimentary cores offshore from the Mauritanian upwelling. The biological model is a classical nitrogen-based trophic chain model, which also computes the nitrogen isotope fractionation. The 2D physical primitive equation model simulates the coastal upwelling circulation and is applied for different sea level scenarios. The effect of the sea level rise, inducing the shelf immersion, seems to be a main factor explaining the organic nitrogen flux and isotopic signal variations along the last deglaciation. This effect is modulated by an upwelling seasonality that may have been much longer at the Last Glacial Maximum, around 10-11 months instead of 4-5 months at present. Between 15 and 5.5 kyr ago, 60% of the sedimentary δ15N variations could be explained by this local shelf immersion effect. This reconstruction also reproduces the strong isotopic fall occurring between 5.5 kyr and the present.
Complete list of metadata

https://hal-insu.archives-ouvertes.fr/insu-03619025
Contributor : Nathalie Pothier Connect in order to contact the contributor
Submitted on : Thursday, March 24, 2022 - 5:38:32 PM
Last modification on : Monday, May 16, 2022 - 8:20:12 AM

File

Global Biogeochemical Cycles -...
Publisher files allowed on an open archive

Licence

Copyright

Identifiers

Collections

Citation

Xavier Giraud, Philippe Bertrand, Véronique Garçon, Isabelle Dadou. Interpretation of the nitrogen isotopic signal variations in the Mauritanian upwelling with a 2D physical-biogeochemical model. Global Biogeochemical Cycles, American Geophysical Union, 2003, 17, ⟨10.1029/2002GB001951⟩. ⟨insu-03619025⟩

Share

Metrics

Record views

29

Files downloads

3