Climatic history of the northeastern United States during the past 3000 years
Many ecosystem processes that influence Earth system feedbacks – vegetation growth, water and nutrient cycling, disturbance regimes – are strongly influenced by multidecadal- to millennial-scale climate variations that cannot be directly observed. Paleoclimate records provide information about t...
Main Authors: | , , , , , , , , , , , , , , , , , , , , , , , , , , |
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Format: | Article |
Language: | English |
Published: |
Copernicus Publications
2017-10-01
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Series: | Climate of the Past |
Online Access: | https://www.clim-past.net/13/1355/2017/cp-13-1355-2017.pdf |
Summary: | Many ecosystem processes that influence Earth system feedbacks –
vegetation growth, water and nutrient cycling, disturbance regimes – are
strongly influenced by multidecadal- to millennial-scale climate variations
that cannot be directly observed. Paleoclimate records provide information
about these variations, forming the basis of our understanding and modeling
of them. Fossil pollen records are abundant in the NE US, but cannot
simultaneously provide information about paleoclimate and past vegetation in
a modeling context because this leads to circular logic. If pollen data are
used to constrain past vegetation changes, then the remaining paleoclimate
archives in the northeastern US (NE US) are quite limited. Nonetheless, a
growing number of diverse reconstructions have been developed but have not
yet been examined together. Here we conduct a systematic review, assessment,
and comparison of paleotemperature and paleohydrological proxies from the NE
US for the last 3000 years. Regional temperature reconstructions (primarily
summer) show a long-term cooling trend (1000 BCE–1700 CE) consistent with
hemispheric-scale reconstructions, while hydroclimate data show gradually
wetter conditions through the present day. Multiple proxies suggest that a
prolonged, widespread drought occurred between 550 and 750 CE. Dry conditions
are also evident during the Medieval Climate Anomaly, which was warmer and
drier than the Little Ice Age and drier than today. There is some
evidence for an acceleration of the longer-term wetting trend in the NE US
during the past century; coupled with an abrupt shift from decreasing to
increasing temperatures in the past century, these changes could have
wide-ranging implications for species distributions, ecosystem dynamics, and
extreme weather events. More work is needed to gather paleoclimate data in
the NE US to make inter-proxy comparisons and to improve estimates of
uncertainty in reconstructions. |
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ISSN: | 1814-9324 1814-9332 |