 |
| Titel |
Persistent influence of ice sheet melting on high northern latitude climate during the early Last Interglacial |
| VerfasserIn |
A. Govin, P. Braconnot, E. Capron, E. Cortijo, J.-C. Duplessy, E. Jansen, L. Labeyrie, A. Landais, O. Marti, E. Michel, E. Mosquet, B. Risebrobakken, D. Swingedouw, C. Waelbroeck |
| Medientyp |
Artikel
|
| Sprache |
Englisch
|
| ISSN |
1814-9324
|
| Digitales Dokument |
URL |
| Erschienen |
In: Climate of the Past ; 8, no. 2 ; Nr. 8, no. 2 (2012-03-14), S.483-507 |
| Datensatznummer |
250005464
|
| Publikation (Nr.) |
 copernicus.org/cp-8-483-2012.pdf |
|
|
|
|
|
| Zusammenfassung |
| Although the Last Interglacial (LIG) is often considered as a possible
analogue for future climate in high latitudes, its precise climate evolution
and associated causes remain uncertain. Here we compile high-resolution
marine sediment records from the North Atlantic, Labrador Sea, Norwegian Sea
and the Southern Ocean. We document a delay in the establishment of peak
interglacial conditions in the North Atlantic, Labrador and Norwegian Seas
as compared to the Southern Ocean. In particular, we observe a persistent
iceberg melting at high northern latitudes at the beginning of the LIG. It
is associated with (1) colder and fresher surface-water conditions in the
North Atlantic, Labrador and Norwegian Seas, and (2) a weaker ventilation of
North Atlantic deep waters during the early LIG (129–125 ka) compared to the
late LIG. Results from an ocean-atmosphere coupled model with insolation as
a sole forcing for three key periods of the LIG show warmer North Atlantic surface waters and stronger
Atlantic overturning during the early LIG (126 ka) than the late LIG
(122 ka). Hence, insolation variations alone do not explain the delay in peak
interglacial conditions observed at high northern latitudes. Additionally,
we consider an idealized meltwater scenario at 126 ka where the freshwater
input is interactively computed in response to the high boreal summer
insolation. The model simulates colder, fresher North Atlantic surface
waters and weaker Atlantic overturning during the early LIG (126 ka)
compared to the late LIG (122 ka). This result suggests that both insolation
and ice sheet melting have to be considered to reproduce the climatic
pattern that we identify during the early LIG. Our model-data comparison
also reveals a number of limitations and reinforces the need for further
detailed investigations using coupled climate-ice sheet models and
transient simulations. |
| |
|
| Teil von |
|
|
|
|
|
|
|
|