 |
| Titel |
A modeling sensitivity study of the influence of the Atlantic meridional overturning circulation on neodymium isotopic composition at the Last Glacial Maximum |
| VerfasserIn |
T. Arsouze, J.-C. Dutay, M. Kageyama, F. Lacan, R. Alkama, O. Marti, C. Jeandel |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1814-9324
|
| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 4, no. 3 ; Nr. 4, no. 3 (2008-09-04), S.191-203 |
| Datensatznummer |
250001742
|
| Publikation (Nr.) |
 copernicus.org/cp-4-191-2008.pdf |
|
|
|
|
|
| Zusammenfassung |
| Using a simple parameterisation that resolves the first order global Nd
isotopic composition (hereafter expressed as εNd in an
Ocean Global Circulation Model, we have tested the impact of different
circulation scenarios on the εNd in the Atlantic for the
Last Glacial Maximum (LGM), relative to a modern control run. Three
different LGM freshwater forcing experiments are performed to test for
variability in the εNd oceanic distribution as a function
of ocean circulation. Highly distinct representations of the ocean
circulation are generated in the three simulations, which drive significant
differences in εNd, particularly in deep waters of the
western part of the basin. However, at the LGM, the Atlantic is more
radiogenic than in the modern control run, particularly in the Labrador
basin and in the Southern Ocean. A fourth experiment shows that changes in
Nd sources and bathymetry drive a shift in the εNd
signature of the basin that is sufficient to explain the changes in the
εNd signature of the northern end-member (NADW or GNAIW
glacial equivalent) in our LGM simulations. All three of our LGM circulation
scenarios show good agreement with the existing intermediate depth
εNd paleo-data. This study cannot indicate the likelihood
of a given LGM oceanic circulation scenario, even if simulations with a
prominent water mass of southern origin provide the most conclusive results.
Instead, our modeling results highlight the need for more data from deep and
bottom waters from western Atlantic, where the εNd change
in the three LGM scenarios is the most important (up to 3 εNd. This would also aid more precise conclusions concerning the
evolution of the northern end-member εNd signature, and
thus the potential use of εNd as a tracer of past oceanic
circulation. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|