The meridional temperature gradient in the eastern North Atlantic during MIS 11 and its link to the ocean-atmosphere system
|Author(s)||Kandiano Evgenia S.1, Bauch Henning A.1, 2, Fahl Kirsten3, Helmke Jan P.4, Roehl Ursula5, Perez-Folgado Marta6, Cacho Isabel7|
|Affiliation(s)||1 : GEOMAR, D-24148 Kiel, Germany.
2 : Mainz Acad Sci Humanities & Literature, Mainz, Germany.
3 : Alfred Wegener Inst Polar & Marine Res, D-27568 Bremerhaven, Germany.
4 : Inst Adv Sustainabil Studies eV, D-14467 Potsdam, Germany.
5 : Univ Bremen, MARUM Ctr Marine Environm Sci, D-28359 Bremen, Germany.
6 : Univ Salamanca, Dept Geol, E-37008 Salamanca, Spain.
7 : Univ Barcelona, Fac Geol, ES-08028 Barcelona, Spain.
|Source||Palaeogeography Palaeoclimatology Palaeoecology (0031-0182) (Elsevier Science Bv), 2012-05 , Vol. 333-334 , P. 24-39|
|WOS© Times Cited||40|
|Keyword(s)||Eastern North Atlantic, Stage 11, North Atlantic Oscillation, Foraminiferal sea surface temperatures, Alkenone sea surface temperatures|
|Abstract||Temporal and spatial patterns in eastern North Atlantic sea-surface temperatures (SST) were reconstructed for marine isotope stage (MIS) 11c using a submeridional transect of five sediment cores. The SST reconstructions are based on planktic foraminiferal abundances and alkenone indices, and are supported by benthic and planktic stable isotope measurements, as well as by ice-rafted debris content in polar and middle latitudes. Additionally, the larger-scale dynamics of the precipitation regime over northern Africa and the western Mediterranean region was evaluated from iron concentrations in marine sediments off NW Africa and planktic delta C-13 in combination with analysis of planktic foraminiferal abundances down to the species level in the Mediterranean Sea. Compared to the modern situation, it is revealed that during entire MIS 11c sensu striae (ss), i.e., between 420 and 398 ka according to our age models, a cold SST anomaly in the Nordic seas co-existed with a warm SST anomaly in the middle latitudes and the subtropics, resulting in steeper meridional SST gradients than during the Holocene. Such a SST pattern correlates well with a prevalence of a negative mode of the modem North Atlantic Oscillation. We suggest that our scenario might partly explain the longer duration of wet conditions in the northern Africa during MIS 11c compared to the Holocene.|