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A Wetter Arctic Coincident With Hemispheric Warming 8,000 Years Ago
Author(s) -
Thomas E. K.,
Castañeda I. S.,
McKay N. P.,
Briner J. P.,
Salacup J. M.,
Nguyen K. Q.,
Schweinsberg A. D.
Publication year - 2018
Publication title -
geophysical research letters
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.007
H-Index - 273
eISSN - 1944-8007
pISSN - 0094-8276
DOI - 10.1029/2018gl079517
Subject(s) - climatology , arctic , environmental science , moisture , northern hemisphere , precipitation , paleoclimatology , atmospheric sciences , evaporation , southern hemisphere , climate change , oceanography , geology , geography , meteorology
Arctic precipitation is predicted to increase this century, with dramatic consequences for high‐latitude systems. Observations remain spatiotemporally limited, hampering determination of the forcings causing wetter Arctic conditions, although two mechanisms have been proposed: enhanced local evaporation and greater poleward atmospheric moisture transport. Here a subcentennial‐resolution multiproxy lake sediment record from western Greenland sheds light on these mechanisms. Cool summers throughout the Northern Hemisphere and in western Greenland 9 to 8 ka are associated with aridity in this region, via reductions in local evaporation and in meridional moisture gradients, which suppressed poleward moisture transport. Summers became more humid starting 8.1 ka, mainly due to increased evaporation from warmer Arctic seas but also to increased poleward moisture transport caused by hemispheric warming. This record provides independent support for predictions of both enhanced local evaporation and increased poleward moisture transport causing wetter Arctic summers in step with global ocean and atmosphere warming.