|
|
|
|
|
Bagniewski, Witold; Meissner, Katrin J.; Menviel, Laurie; Brennan, Catherine E.. |
We perform idealized experiments of a Heinrich Stadial using an oxygen-isotope-enabled Earth System Climate Model. Our results compare relatively well with the planktic and benthic delta O-18 records of Heinrich Stadials 1 and 4. We find that changes in surface delta O-18(c) can be equally attributed to the "temperature effect" due to fractionation during calcification; the "circulation and climate effect" due to changes in circulation, precipitation, and evaporation; and the "meltwater effect" due to the addition and subsequent advection of depleted fresh water from continental ice sheets. In contrast, the meltwater effect and circulation and climate effect have only a small impact on benthic delta O-18(c) during the cessation of the Atlantic Meridional... |
Tipo: Text |
|
Ano: 2015 |
URL: https://archimer.ifremer.fr/doc/00351/46253/46085.pdf |
| |
|
|
Bagniewski, Witold; Meissner, Katrin J.; Menviel, Laurie. |
We present the first transient simulations of Marine Isotope Stage 3 (MIS 3) performed with an oxygen isotope-enabled climate model. Our simulations span several Dansgaard-Oeschger cycles and three Heinrich stadials and are directly compared with oxygen isotope records from 13 sediment and 2 ice cores. Our results are consistent with a 30-50% weakening of the Atlantic Meridional Overturning Circulation during Dansgaard-Oeschger stadials and a complete shutdown during Heinrich stadials. We find that the simulated delta O-18 anomalies differ significantly between Heinrich stadials and non-Heinrich stadials. This difference is mainly due to different responses in ocean circulation, and therefore climate, impacting oceanic delta O-18, while the volume of... |
Tipo: Text |
Palavras-chave: MIS3; Model-data comparison; Heinrich events; Dansgaard-Oeschger cycles; Delta O-18; AMOC. |
Ano: 2017 |
URL: https://archimer.ifremer.fr/doc/00420/53180/55067.pdf |
| |
|
|
|