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Late Holocene storm-trajectory changes inferred from the oxygen isotope composition of lake diatoms, south Alaska
Schiff, C.J., Kaufman, D.S., Wolfe, A.P., Dodd, J., and Sharp, Z.
Mica Lake is located in the Prince William Sound of south Alaska. The lake is located 1 km from the coast at 100 m a.s.l. Sediment cores were recovered from Mica Lake in the summer of 2006, and water samples were collected from over 30 lakes in south-central Alaska.
Oxygen isotope ratios of diatoms (δ18Odiatom):
δ18Odiatom is controlled by the temperature and oxygen isotope composition of lake water (δW). δW in Mica Lake reflects the oxygen isotope ratios of precipitation, which change with temperature and storm tracks in the North Pacific. Therefore, the δ18Odiatom values at Mica Lake are, in part, controlled by changes in climate.
We interpret variability of δ18Odiatom values from Mica Lake to reflect changes in storm track trajectory for storms intersecting south Alaska. Changes in storm trajectories are related to the strength of the Aleutian Low. West-to-east storm trajectories correspond to more negative δ18Odiatom values and weaker Aleutian Low while more positive δ18Odiatom values are from south-to-north storm trajectories and stronger Aleutian Low. The Mica Lake record suggests changes in atmospheric circulation during the late Holocene.