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Titel |
Eurasian Arctic climate over the past two millennia as recorded in the Akademii Nauk ice core (Severnaya Zemlya, Russian Arctic) |
VerfasserIn |
D. Fritzsche, T. Opel, H. Meyer |
Konferenz |
EGU General Assembly 2012
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Medientyp |
Artikel
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Sprache |
Englisch
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Digitales Dokument |
PDF |
Erschienen |
In: GRA - Volume 14 (2012) |
Datensatznummer |
250066065
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Zusammenfassung |
In the context of the ongoing and future strong warming of the Arctic detailed knowledge of
past climate changes in particular on a regional scale is crucial. An ice core drilled on the
Akademii Nauk (AN) ice cap (Severnaya Zemlya, 80.52Ë N, 94.82Ë E) at a relatively low
altitude of about 750 m a.s.l. has shown to provide high-resolution climate proxy data
from the Central Russian Arctic, although the ice cap is affected by melt-water
infiltration.
Here for the first time, we present δ18O and major ion records for the last about two
millennia. The age-depth relationship of the core is based on annual layer counting and
volcanic reference layers for cross-checking (Bezymianny 1956, Katmai 1912, Laki 1783,
unknown volcano 1259, Eldgja 934). The multi-annual AN δ18O data are highly
correlated to instrumental temperature data from the Western Eurasian Arctic (e.g.
Vardø/Northern Norway) and thus provide a valuable near-surface temperature
proxy for this region, also underlined by the good coincidence with the Austfonna
(Svalbard) ice core δ18O data. The long-term decrease of AN δ18O data does not
solely reflect climate cooling but probably also a growing of AN ice cap. AN δ18O
record reveal major temperature changes over the last centuries, e.g. the absolute
minimum around 1800 and the exceptional warming to a maximum in early 20th
century (Early Twentieth Century Warming – ETCW), representing the temperature
maximum of the record. By comparison with meteorological data it can be shown that a
double-peak structure of the ETCW is a peculiarity of the Barents and Kara Sea
region.
Neither a pronounced Medieval Climate Anomaly nor a Little Ice Age could be
identified. In contrast, AN ice-core records show evidence for several abrupt warming
and cooling events such as in the 15th and 16th centuries. These abrupt changes
might be analogous to the ETCW and probably caused by shifts in the atmospheric
circulation patterns and accompanied sea-ice feedbacks in the Barents and Kara seas
region that highlight the role of the internal variability of the Arctic climate system. |
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