Major shifts in multidecadal moisture variability in the Mid‐Atlantic region during the last 240 years

Abstract

The paucity of high‐resolution paleoclimate records limits our ability to extend instrumental data into a longer time‐frame and to better understand multidecadal climate variations in the Mid‐Atlantic region. Here we present an ∼2 year‐resolution endogenic calcite δ18O record for the last ∼240 years from a freeze core at White Lake in northern New Jersey. The δ18O data, consistent with the paleosalinity reconstructions from Chesapeake Bay, suggest regional‐scale multidecadal moisture variations, including dry conditions at 1780–1840, wet conditions at 1840–1920, and ∼20 year moisture oscillations after 1920. We attribute these moisture changes to shifts in the extent and location of the jet stream and resultant change in storm track trajectories, with eastward and seaward displacement of storm tracks corresponding to dry climate. The increase in moisture variability since 1920, shortly after the steady increase in global air temperature, suggests that change in mean climate state can induce large changes in moisture variability.

Spatiotemporal Snowfall Trends in Central New York

“…For example, Grimaldi (2008) discovered that during the El Niño (warm) phase of the El Niño-Southern Oscillation (ENSO), early winter months in Syracuse are generally warmer, with anomalously low snowfall totals. For example, Zhao et al (2010) suggested that changes in the AMO result in shifts in the magnitude and location of the jet stream. Also, during El Niño years major snow events are 5 times as likely to occur in Syracuse.…”

A 1600-year diatom record of hydroclimate variability from Wolf Lake, New York

“…The abrupt rise of small Discostella percentages during the AD 1860s that is represented in the Wolf-62 core was apparently not accompanied by unusually abrupt shifts in regional lake levels, temperatures, or ice cover (Stager and Thill, 2010; Wilcox et al, 2007; Zhao et al, 2010). The increase in Discostella abundances might instead be related to nutrient enrichment from human activity in the watershed, as has been documented for D. stelligera in Walden Pond, Massachusetts (Köster et al, 2005).…”