Holocene North Atlantic surface circulation and climatic variability: evidence from diatom records

Malgorzata Witak, Anna Wachnicka, Antoon Kuijpers, Simon Troelstra, Maarten A. Prins, Andrzej Witkowski

Publikation: Bidrag til tidsskriftArtikelForskningpeer review

29 Citationer (Scopus)

Abstrakt

Diatom analyses have been performed on a 425 cm long Holocene marine sediment sequence from the North Atlantic south of Iceland and a 920 cm sediment core spanning the last c. 7500 years from Skalafjord, Faeroe Islands. Additional core data include stable isotopes and results from magnetic susceptibility measurements, while chronostratigraphic control has been provided by AMS 14C measurements. The diatom records reveal distinct changes in North Atlantic surface circulation and climate that have been correlated with published terrestrial and marine records. Initial Holocene warming is dated at 9900 14C years BP, and after a Preboreal cold spell enhanced North Atlantic Current activity and warming prevailed from 9600 to 8800 14C years BP. From 8800 to 8000 14C years BP the advection of warm Atlantic water masses weakened, presumably under atmospheric circulation conditions characterized by a dominating negative NAO. Prior to the Holocene Climatic Optimum (6000-5000 14C years BP) distinct hydrographic gradients existed in the northern North Atlantic that were probably most pronounced during the reported '8200 cal. years BP cold event'. After 5000 14C years BP both core records indicate increased climate instability and periods of cooling ('Neoglaciation'), with enhanced cyclone activity affecting the northern North Atlantic particularly at around 4700, 4200, 3200, 2000, 1500 and 1000 14C years BP.

OriginalsprogEngelsk
Sider (fra-til)85-96
Antal sider12
TidsskriftHolocene
Vol/bind15
Udgave nummer1
DOI
StatusUdgivet - jan. 2005

Programområde

  • Programområde 5: Natur og klima

Fingeraftryk

Dyk ned i forskningsemnerne om 'Holocene North Atlantic surface circulation and climatic variability: evidence from diatom records'. Sammen danner de et unikt fingeraftryk.

Citationsformater