Dpto. Astrofísica y Ciencias de la Atmósfera; Facultad de Ciencias Físicas; Universidad Complutense de Madrid (UCM)
Instituto de Geociencias (UCM-CSIC), Madrid, Spain
Abstract. Imposing freshwater flux (FWF) variations in the North Atlantic is an effective method to cause reorganizations of the Atlantic Meridional Overturning Circulation (AMOC) in climate models. Through this approach, models have been able to reproduce the abrupt climate changes of the last glacial period. Such exercises have been useful for gaining insight into a wealth of processes regarding the widespread climatic consequences of AMOC variations. However, an issue that has passed unnoticed is the fact that the timing of the FWF applied in these studies is inconsistent with reconstructions. Here we focus on the deglaciation to show that imposing a FWF that is derived from the sea-level record results in a simulated AMOC evolution in a poor fit with the data, revealing an inconsistency between the generally accepted FWF mechanism and the resulting climatic impacts. Based on these negative results, we propose that the trigger of deglacial abrupt climate changes is not yet fully identified and that mechanisms other than FWF forcing should be explored more than ever.
This preprint has been withdrawn.
How to cite. Alvarez-Solas, J., Montoya, M., and Robinson, A.: Deglacial abrupt climate changes: not simply a freshwater problem, Clim. Past Discuss. [preprint], https://doi.org/10.5194/cp-2019-96, 2019.
Received: 02 Aug 2019 – Discussion started: 16 Sep 2019
Modelling the past abrupt climate changes often resorts to the use of freshwater flux (FWF) in the North Atlantic as an effective method to cause reorganizations of the Atlantic Meridional Overturning Circulation. This procedure has allowed to reproduce the timing of the events. However, the required FWF is inconsistent with reconstructions. Conversely, using a forcing derived from the sea-level record results in a poor fit with the data, highlighting the need of exploring other mechanisms.
Modelling the past abrupt climate changes often resorts to the use of freshwater flux (FWF) in...