Open AccessNew insights into Holocene atmospheric circulation dynamics in central Scandinavia inferred from oxygen‐isotope records of lake‐sediment cellulose
Author(s) -
ST. AMOUR NATALIE A.,
HAMMARLUND DAN,
EDWARDS THOMAS W.D.,
WOLFE BRENT B.
Publication year - 2010
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/j.1502-3885.2010.00169.x
Subject(s) - holocene , geology , oceanography , isotopes of oxygen , atmospheric circulation , northern hemisphere , westerlies , transect , precipitation , paleoclimatology , climatology , climate change , physical geography , geography , geochemistry , meteorology
St. Amour, N. A., Hammarlund, D., Edwards, T. W. D. & Wolfe, B. B. 2010: New insights into Holocene atmospheric circulation dynamics in central Scandinavia inferred from oxygen‐isotope records of lake‐sediment cellulose. Boreas , Vol. 39, pp. 770–782. 10.1111/j.1502‐3885.2010.00169.x. ISSN 0300‐9843 Cellulose‐inferred lakewater oxygen‐isotope records have been obtained from two hydrologically open basins (Lake Spåime and Lake Svartkälstjärn), located on a west–east transect across central Sweden, to investigate changes in atmospheric circulation patterns during the Holocene. The Lake Spåime δ 18 O record is sensitive to changes in the seasonal distribution of precipitation in the Scandes Mountains of west‐central Sweden, and thus generally portrays variations in δ 18 O of precipitation (δ 18 O P ) that are governed predominantly by the influence of air masses originating from the North Atlantic. In contrast, the Lake Svartkälstjärn δ 18 O record appears to reflect the varying influence of air masses delivering moisture from the North Atlantic and the Baltic Sea. A comparison of inferred changes in δ 18 O P over the Holocene between the two sites reveals systematic patterns of variability over widely different time scales. These include: (1) a previously recognized long‐term regional decline in δ 18 O P , possibly in response to the declining vigour of Northern Hemisphere atmospheric circulation related to decreasing summer solar insolation; (2) newly identified inverse centennial‐ to millennial‐scale δ 18 O P fluctuations at the two sites that may be linked to changes in modes of atmospheric circulation analogous to those described at interannual to multidecadal time scales by the North Atlantic Oscillation (NAO) index; and (3) a prolonged interval of apparent climatic stability in the mid‐Holocene ( c . 6300–4200 cal. yr BP) characterized by persistently negative NAO‐like circulation.