A 290-a record of atmospheric circulation over the North Pacific from a Mt. Logan ice core, Yukon Territory
Calibrations between sodium (Na+) concentrations from a Mt. Logan ice core and sea level pressure (SLP) series show that Na+ concentrations are closely correlated with the autumn-time (SeptemberOctober-November) Aleutian low (AleuLow). A deepening of the AleuLow strengthens the transport of sea-salt aerosols from the North Pacific to the Mt. Logan region. The Mt. Logan Na+ record is used to develop a 292 a (1688～1979) reconstruction of the AleuLow revealing a dramatic intensification of atmospheric circulation over the North Pacific region since the 20th century. Mean SLP of the AleuLow was about 1 hPa lower during the 20th century than during prior periods. The strongest deepening of the AleuLow appeared in the 1950s. Significant correlations are also found between the Mt. Logan AleuLow proxy series and the Pacific decadal oscillation (PDO) and Pacific circulation (PC) index during the 20th century. Evolutionary spectral analysis of the proxy record shows significant periodicities from 15 to 30 a consistent with PDO fluctuations and the bidecadal oscillation of North Pacific atmosphere-ocean circulation. A period of 11 a in the AleuLow record may be associated with the Schwabe 11-a cycle of sunspot activity. Additional longer ice core records from this region will aid in the efforts to further understand the climatic change over the North Pacific region.
作 者： KANG Shichang MAYEWSKI Paul A YAN Yuping 作者单位： KANG Shichang(Institute of Tibetan Plateau Research, Chine;Climate Change Institute, University of Maine, Orono, ME 04469, USA;Laboratory of Cryosphere and Environment, Cold and Arid Regions Environmental and Engineering Research Institute, Chinese Academy of Sciences,Lanzhou,730000,China)MAYEWSKI Paul A(Climate Change Institute, University of Maine, Orono, ME 04469, USA)
YAN Yuping(National Climate Center, Beijing 100081, China)
刊 名： 海洋学报（英文版） SCI 英文刊名： ACTA OCEANOLOGICA SINICA 年，卷(期)： 2005 24(4) 分类号： P7 关键词： atmospheric circulation ice core records North Pacific