Centennial eolian cyclicity in the Great Plains, USA: a dominant climate pattern of wind transport over the past 4000 years?

• Main Authors: Schwalb, Antje, Dean, Walter E., Fritz, Sherilyn C., Geiss, Christoph E., Kromer, Bernd
• Format: Text
• Language: unknown
• Published: DigitalCommons@University of Nebraska - Lincoln 2010
• Subjects: Earth Sciences; Pacific; North Atlantic
• Online Access: https://digitalcommons.unl.edu/geosciencefacpub/120; https://digitalcommons.unl.edu/context/geosciencefacpub/article/1120/viewcontent/Fritz_QSR_2010_Centennial_eolian.pdf

Proxy evidence at decadal resolution from Late Holocene sediments from Pickerel Lake, northeastern South Dakota, shows distinct centennial cycles (400-700 years) in magnetic susceptibility; contents of carbonate, organic carbon, and major elements; abundance in ostracodes; and δ18O and δ13C values in calcite. Proxies indicate cyclic changes in eolian input, productivity, and temperature. Maxima in magnetic susceptibility are accompanied by maxima in aluminum and iron mass accumulation rates (MARs), and in abundances of the ostracode Fabaeformiscandona rawsoni. This indicates variable windy, and dry conditions with westerly wind dominance, including during the Medieval Climate Anomaly. Maxima in carbonates, organic carbon, phosphorous, and high δ13C values of endogenic calcite indicate moister and less windy periods with increased lake productivity, including during the Little Ice Age, and alternate with maxima of eolian transport. Times of the Maunder, Spörer and Wolf sunspot minima are characterized by maxima in δ18O values and aluminum MARs, and minima in δ13C values and organic carbon content. We interpret these lake conditions during sunspot minima to indicate decreases in lake surface water temperatures of up to 4-5 °C associated with decreases in epilimnetic productivity during summer. We propose that the centennial cycles are triggered by solar activity, originate in the tropical Pacific, and their onset during the Late Holocene is associated with insolation conditions driven by precession. The cyclic pattern is transmitted from the tropical Pacific into the atmosphere and transported by westerly winds into the North Atlantic realm where they strengthen the Atlantic Meridional Overturning Circulation during periods of northern Great Plains wind maxima. This consequently leads to moister climates in Central and Northern Europe. Thus, Pickerel Lake provides evidence for mechanisms of teleconnections including an atmospheric link bridging between the different climate regimes from the tropical Pacific to the ...