FN Archimer Export Format PT J TI Highly variable Pliocene sea surface conditions in the Norwegian Sea BT AF BACHEM, Paul E. RISEBROBAKKEN, Bjorg DE SCHEPPER, Stijn MCCLYMONT, Erin L. AS 1:1;2:1;3:1;4:2; FF 1:;2:;3:;4:; C1 Bjerknes Ctr Climate Res, Uni Res Climate, Jahnebakken 5, N-5007 Bergen, Norway. Univ Durham, Dept Geog, Durham DH1 3LE, England. C2 BCCR, NORWAY UNIV DURHAM, UK IN DOAJ IF 3.174 TC 20 UR https://archimer.ifremer.fr/doc/00495/60710/65332.pdf https://archimer.ifremer.fr/doc/00495/60710/65333.pdf LA English DT Article CR IMAGES 1-MD101 BO Marion Dufresne AB The Pliocene was a time of global warmth with small sporadic glaciations, which transitioned towards the larger-scale Pleistocene glacial-interglacial variability. Here, we present high-resolution records of sea surface temperature (SST) and ice-rafted debris (IRD) in the Norwegian Sea from 5.32 to 3.14 Ma, providing evidence that the Pliocene surface conditions of the Norwegian Sea underwent a series of transitions in response to orbital forcing and gateway changes. Average SSTs are 2 degrees C above the regional Holocene mean, with notable variability on millennial to orbital timescales. Both gradual changes and threshold effects are proposed for the progression of regional climate towards the Late Pliocene intensification of Northern Hemisphere glaciation. Cooling from 4.5 to 4.3 Ma may be linked to the onset of poleward flow through the Bering Strait. This cooling was further intensified by a period of cool summers due to weak obliquity forcing. A 7 degrees C warming of the Norwegian Sea at 4.0Ma suggests a major increase in northward heat transport from the North Atlantic, leading to an enhanced zonal SST gradient in the Nordic Seas, which may be linked to the expansion of sea ice in the Arctic and Nordic Seas. A warm Norwegian Sea and enhanced zonal temperature gradient between 4.0 and 3.6 Ma may have been a priming factor for increased glaciation around the Nordic Seas due to enhanced evaporation and precipitation at high northern latitudes. PY 2017 PD SEP SO Climate Of The Past SN 1814-9324 PU Copernicus Gesellschaft Mbh VL 13 IS 9 UT 000409996100002 BP 1153 EP 1168 DI 10.5194/cp-13-1153-2017 ID 60710 ER EF