Analyses of sediment cores from Jellybean Lake, a small, evaporation-insensitive groundwater-fed lake, provide a record of changes in North Pacific atmospheric circulation for the la
st 7500 yr at 5- to 30-yr resolution. Isotope hydrology data from the southern Yukon indicate that the oxygen isotope composition of water from Jellybean Lake reflects the composition of mean-annual precipitation, δ
18O
p. Recent changes in the δ
18O of Jellybean sedimentary calcite (δ
18O
ca) correspond to changes in the North Pacific Index (NPI), a measure of the intensity and position of the Aleutian Low (AL) pressure sy
stem. This sugge
sts that δ
18O
p variability was related to the degree of fractionation during moi
sture transport from the Gulf of Alaska across the St.
Elias Mountains and that Holocene shifts were controlled by the intensity and position of the AL. Following this model, between
7500 and 4500 cal yr B.P., long-term trends sugge
st a predominantly weaker and/or we
stward AL. Between
4500 and 3000 cal yr B.P. the AL shifted ea
stward or intensified before shifting we
stward or weakening between
3000 and 2000 cal yr B.P. Rapid shifts ea
stward and/or intensification occurred
1200 and 300 cal yr B.P. Holocene changes in North Pacific atmospheric circulation inferred from Jellybean Lake oxygen isotopes correspond with late Holocene glacial advances in the St. Elias Mountains, changes in North Pacific salmon abundance, and shifts in atmospheric circulation over the Beaufort Sea.