caa a22 4500 605474265 CHVBK 20210128100346.0 cr unu---uuuuu 210128e20150101xx s 000 0 eng 10.1007/s00382-014-2274-6 doi (NATIONALLICENCE)springer-10.1007/s00382-014-2274-6 Historical analogues of the recent extreme minima observed in the Atlantic meridional overturning circulation at 26°N [Elektronische Daten] [Adam Blaker, Joël Hirschi, Gerard McCarthy, Bablu Sinha, Sarah Taws, Robert Marsh, Andrew Coward, Beverly de Cuevas] Observations of the Atlantic meridional overturning circulation (AMOC) by the RAPID 26°N array show a pronounced minimum in the northward transport over the winter of 2009/10, substantially lower than any observed since the initial deployment in April 2004. It was followed by a second minimum in the winter of 2010/2011. We demonstrate that ocean models forced with observed surface fluxes reproduce the observed minima. Examining output from five ocean model simulations we identify several historical events which exhibit similar characteristics to those observed in the winter of 2009/10, including instances of individual events, and two clear examples of pairs of events which happened in consecutive years, one in 1969/70 and another in 1978/79. In all cases the absolute minimum, associated with a short, sharp reduction in the Ekman component, occurs in winter. AMOC anomalies are coherent between the Equator and 50°N and in some cases propagation attributable to the poleward movement of the anomaly in the wind field is observed. We also observe a low frequency (decadal) mode of variability in the anomalies, associated with the North Atlantic Oscillation (NAO). Where pairs of events have occurred in consecutive years we find that atmospheric conditions during the first winter correspond to a strongly negative Arctic Oscillation (AO) index. Atmospheric conditions during the second winter are indicative of a more regional negative NAO phase, and we suggest that this persistence is linked to re-emergence of sea surface temperature anomalies in the North Atlantic for the events of 1969/70 and 2009/10. The events of 1978/79 do not exhibit re-emergence, indicating that the atmospheric memory for this pair of events originates elsewhere. Observation of AO patterns associated with cold winters over northwest Europe may be indicative for the occurrence of a second extreme winter over northwest Europe. Springer-Verlag Berlin Heidelberg, 2014 AMOC nationallicence Minimum nationallicence Events nationallicence RAPID nationallicence Model nationallicence Observations nationallicence SST anomalies nationallicence Re-emergence nationallicence Blaker Adam National Oceanography Centre, SO14 3ZH, Southampton, UK aut Hirschi Joël National Oceanography Centre, SO14 3ZH, Southampton, UK aut McCarthy Gerard National Oceanography Centre, SO14 3ZH, Southampton, UK aut Sinha Bablu National Oceanography Centre, SO14 3ZH, Southampton, UK aut Taws Sarah University of Southampton, National Oceanography Centre, SO14 3ZH, Southampton, UK aut Marsh Robert University of Southampton, National Oceanography Centre, SO14 3ZH, Southampton, UK aut Coward Andrew National Oceanography Centre, SO14 3ZH, Southampton, UK aut de Cuevas Beverly National Oceanography Centre, SO14 3ZH, Southampton, UK aut Climate Dynamics Springer Berlin Heidelberg 44/1-2(2015-01-01), 457-473 0930-7575 44:1-2<457 2015 44 382 https://doi.org/10.1007/s00382-014-2274-6 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00382-014-2274-6 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Blaker Adam National Oceanography Centre, SO14 3ZH, Southampton, UK aut NATIONALLICENCE 700 1- Hirschi Joël National Oceanography Centre, SO14 3ZH, Southampton, UK aut NATIONALLICENCE 700 1- McCarthy Gerard National Oceanography Centre, SO14 3ZH, Southampton, UK aut NATIONALLICENCE 700 1- Sinha Bablu National Oceanography Centre, SO14 3ZH, Southampton, UK aut NATIONALLICENCE 700 1- Taws Sarah University of Southampton, National Oceanography Centre, SO14 3ZH, Southampton, UK aut NATIONALLICENCE 700 1- Marsh Robert University of Southampton, National Oceanography Centre, SO14 3ZH, Southampton, UK aut NATIONALLICENCE 700 1- Coward Andrew National Oceanography Centre, SO14 3ZH, Southampton, UK aut NATIONALLICENCE 700 1- de Cuevas Beverly National Oceanography Centre, SO14 3ZH, Southampton, UK aut NATIONALLICENCE 773 0- Climate Dynamics Springer Berlin Heidelberg 44/1-2(2015-01-01), 457-473 0930-7575 44:1-2<457 2015 44 382