LATE HOLOCENE PRECIPITATION RECONSTRUCTED FROM FAYETTEVILLE GREEN LAKE, NY, VARVED SEDIMENTS

Concerns about climate change necessitate establishing long term paleoclimate records to better understand natural variations and extreme climate scenarios. One tool to establish such records are lake varves. Here, we present varve data from Fayetteville Green Lake near Syracuse New York. These sediments contain alternating layers of carbonate sediment and coarser clastic sediment that are deposited annually. The carbonates are deposited during the warmer spring and summer months while the coarser clastics are deposited during the winter. Fayetteville Green Lake is located approximately 15km east of Syracuse and represents the eastern edge of the Great Lakes watershed. This lake is nearly 60 meters deep, lies within a small drainage basin, and is oligotrophic in nature due to limited nutrient intake.

The thickness of carbonate layers within the varved sediments taken from Fayetteville Green Lake is strongly correlated with annual precipitation in the region. The variability in precipitation reflects differing airmass source regions and allows a mean hemispheric flow to be established. Initial analyses of Fayetteville Green's core samples established a paleoclimate record extending ca. 425 years. Here, the varve record is extended to cover the last few millennia using additional, longer cores from Fayetteville Green Lake. Spectral analyses are used to investigate the periodic components of precipitation variability in central New York during the late Holocene. The cyclic components of the time series are presented in light of potential teleconnective climate patterns that have been active through the late Holocene. This work supports and advances ongoing paleoclimate reconstructions from varved sediments within the Great Lakes watershed that have been used to establish the presence of decadal and sub-decadal teleconnective patterns, such as the Pacific/North American (PNA) pattern. This work also correlates the annual precipitation with the Trough Intensity Index (TII) and Trough Axis Index (TAI) (Bradbury et al., 2002).