Abstract:
Late Holocene (2200-present) spring water temperatures from Chesapeake
Bay in the eastern United States determined from magnesium/calcium
(Mg/Ca) ratios in the ostracode Loxoconcha. The file provides a
composite temperature curve constructed from 3 sediment core Mg/Ca
records. Details on chronology, methodology, and implications for
late Holocene climate variability can be found in the original
... reference.
Abstract (from the online documentation)
We present paleoclimate evidence for rapid (< 100) shifts of of ~2-4C
in Chesapeake Bay (CB) temperature ~2100, 1600, 950, 650, 400 and 150
years before present (years BP) reconstructed from magnesium/calcium
(Mg/Ca) paleothermometry. These include large temperature excursions
during the Little Ice Age (~1400-1900 AD) and the Medieval Warm Period
(~800-1300 AD) possibly related to changes in the strength of North
Atlantic thermohaline circulation (THC). Evidence is presented for a
long period of sustained regional and North Atlantic-wide warmth with
low-amplitude temperature variability between ~450 and 1000 AD. In
addition to centennial-scale temperature shifts, the existence of
numerous temperature maxima between 2200 and 250 years BP (average ~70
years) suggests that multi-decadal processes typical of the North
Atlantic Oscillation (NAO) are an inherent feature of late Holocene
climate. However, late 19th and 20th century temperature extremes in
Chesapeake Bay associated with NAO climate variability exceeded those
of the prior 2000 years, including the interval 450-1000 AD by 2-3C,
suggesting anomalous recent behavior of the climate system. 
