Relationship between Holocene climate variations over southern Greenland and eastern Baffin Island and synoptic circulation pattern

TitleRelationship between Holocene climate variations over southern Greenland and eastern Baffin Island and synoptic circulation pattern
Publication TypeJournal Article
Year of Publication2009
AuthorsFrechette, B, de Vernal, A
JournalClimate of the Past
Volume5
Issue3
Pagination347-359
Date Published2009
ISBN Number1814-9324
Keywordsarctic canada, cal kyr bp, data-base, dinoflagellate cyst assemblages, high-latitudes, modern analogs, north-atlantic, pollen spectra, radiocarbon age calibration, sea-surface temperatures
Abstract

Lake pollen records from southwest Greenland and eastern Baffin Island show strong regionalism in climate trends of the last 7000 cal years. July surface air temperature reconstructions from pollen indicate larger amplitude cooling in southwest Greenland (>3.0 degrees C) than in eastern Baffin Island (<1.0 degrees C). This west-east gradient in climate change is consistent with August sea-surface temperature reconstructions from dinocyst records that indicate decreasing temperature and/or strength of the North Atlantic Current to the east during the Holocene while the eastern Canadian margins under the Labrador Current influence display slight warming. Complementary to air and sea-surface temperature records, the lake pollen data led to reconstruct increased cloudiness in southern Greenland, which points to increasing cyclonic activity since 7000 cal years BP west of Greenland. Together, the terrestrial and marine records of the northwest North Atlantic therefore suggest a shift from a dominant NAO+ during the early-mid Holocene to dominant NAO- in the late Holocene.