Calibrations between sodium (Na+) concentrations from a Mt. Logan ice core and sea level pressure (SLP) series show that Na+ concen-trations are closely correlated with the autumn-time (September—October—November) Aleutian low (AleuLow). A deepening of theAleuLow strengthens the transport of sea-salt aerosols from the North Pacific to the Mt. Logan region. The Mt. Logan Na+ record isused to develop a 292 a (1688~1979) reconstruction of the AleuLow revealing a dramatic intensification of atmospheric circulationover the North Pacific region since the 20th century. Mean SLP of the AleuLow was about 1 hPa lower during the 20th century thanduring prior periods. The strongest deepening of the AleuLow appeared in the 1950s. Significant correlations are also found betweenthe Mt. Logan AleuLow proxy series and the Pacific decadal oscillation (PDO) and Pacific circulation (PC) index during the 20th cen-tury. Evolutionary spectral analysis of the proxy record shows significant periodicities from 15 to 30 a consistent with PDO fluctuationsand the bidecadal oscillation of North Pacific atmosphere-ocean circulation. A period of 11 a in the AleuLow record may be associatedwith the Schwabe 11-a cycle of sunspot activity. Additional longer ice core records from this region will aid in the efforts to further un-derstand the climatic change over the North Pacific region. Calibrations between sodium (Na +) concentrations from a Mt. Logan ice core and sea level pressure (SLP) series show that Na + concen-trations are closely correlated with the autumn-time (September-October- November) Aleutian low (AleuLow). A deepening of theAleuLow strengthens the transport of sea-salt aerosols from the North Pacific to the Mt. Logan region. The Mt. Logan Na + record isused to develop a 292 a (1688 ~ 1979) reconstruction of the AleuLow revealing a dramatic intensification of atmospheric overrun the North Pacific region since the 20th century. Mean SLP of the AleuLow was about 1 hPa lower during the 20th century thanduring prior periods. The strongest deepening of the AleuLow was in the 1950s. Significant correlations are also found betweenthe Mt. Logan AleuLow proxy series and the Pacific decadal oscillation (PDO) and Pacific circulation (PC) index during the 20th cen-tury. Evolutionary spectral analysis of the proxy record shows significant periodicities f rom 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 un-derstand the climatic change over the North Pacific region.