Climate and oceanographic variability in the SW Barents Sea during the Holocene

The Holocene section of the marine sediment core PSh-5159N, located in the SW Barents Sea, has been studied at high resolution with a multiproxy approach. A well-stratified water column occurred at the site 11-9.8 ka BP. The stratification was probably a result of a winter sea ice cover and/or fresh, warm surface waters during summer. Stratification and resultant reduction in air-sea interaction allowed for warmer bottom water temperatures. The general situation 11-9.8 ka BP could have been associated with an anomalous high-pressure system over the Nordic Seas and the Arctic Ocean. During the 11-10.5 ka BP interval the polar front was located close to the Barents Sea margin. The polar front moved towards the site from 10.5 ka BP, and from 9.8 to 7.5 ka BP it was probably located close to the site. At 7.5 ka BP the polar front retreated eastwards as the present-day oceanographic pattern established. The mid Holocene was in general characterized by rather stable conditions. In contrast, highly variable conditions are recorded throughout the late Holocene. Episodic expansions of the coastal water influenced zone are typical for the last 2.5 ka BP. Predominantly cold conditions and reduced southwesterly wind strength are suggested during these episodes. The Holocene temperature variability seems in general to be of larger amplitude than instrumentally recorded temperature changes in the SW Barents Sea.