In:
Climate of the Past, Copernicus GmbH, Vol. 14, No. 11 ( 2018-11-20), p. 1755-1781
Abstract:
Abstract. During the last glacial period Northern Hemisphere climate was characterized
by extreme and abrupt climate changes, so-called Dansgaard–Oeschger (DO)
events. Most clearly observed as temperature changes in Greenland ice-core
records, their climatic imprint was geographically widespread. However, the
temporal relation between DO events in Greenland and other regions is
uncertain due to the chronological uncertainties of each archive, limiting
our ability to test hypotheses of synchronous change. In contrast, the
assumption of direct synchrony of climate changes forms the basis of many
timescales. Here, we use cosmogenic radionuclides (10Be,
36Cl, 14C) to link Greenland ice-core records to
U∕Th-dated speleothems, quantify offsets between the two timescales, and
improve their absolute dating back to 45 000 years ago. This approach allows
us to test the assumption that DO events occurred synchronously between
Greenland ice-core and tropical speleothem records with unprecedented
precision. We find that the onset of DO events occurs within synchronization
uncertainties in all investigated records. Importantly, we demonstrate that
local discrepancies remain in the temporal development of rapid climate
change for specific events and speleothems. These may either be related to
the location of proxy records relative to the shifting atmospheric fronts or
to underestimated U∕Th dating uncertainties. Our study thus highlights
the potential for misleading interpretations of the Earth system when
applying the common practice of climate wiggle matching.
Type of Medium:
Online Resource
ISSN:
1814-9332
DOI:
10.5194/cp-14-1755-2018
DOI:
10.5194/cp-14-1755-2018-supplement
Language:
English
Publisher:
Copernicus GmbH
Publication Date:
2018
detail.hit.zdb_id:
2217985-9
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