Late Holocene climate changes in the Eurasian Arctic recorded in the Akademii Nauk ice core (Severnaya Zemlya)
The 724 m deep ice core drilled recently on the relatively low-altitude Akademii Nauk (AN) ice cap (Severnaya Zemlya, 80.52°N, 94.82°E, about 750 m a.s.l.) is shown to provide high-resolution climate proxy data from the Western Eurasian Arctic, although the ice cap is affected by melt water infiltra...
| Main Authors: | , , |
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| Format: | Conference Object |
| Language: | unknown |
| Published: |
2011
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| Subjects: | |
| Online Access: | https://epic.awi.de/id/eprint/23516/ https://hdl.handle.net/10013/epic.36468 |
| Summary: | The 724 m deep ice core drilled recently on the relatively low-altitude Akademii Nauk (AN) ice cap (Severnaya Zemlya, 80.52°N, 94.82°E, about 750 m a.s.l.) is shown to provide high-resolution climate proxy data from the Western Eurasian Arctic, although the ice cap is affected by melt water infiltration. We present stable water isotope data (d 18O and deuterium excess) for approximately the last two millennia in annual to decadal resolution. The core chronology is based on volcanic reference layers and annual layer counting (stable isotopes). The multi-annual AN d18 O data are highly correlated to instrumental temperature data from the Western Eurasian Arctic (e.g. r=0.76 for VardÞ/Northern Norway, 1840-1998) and thus provide a valuable near-surface temperature proxy for this region. AN d 18 O data reveal major temperature changes in the last two millennia, e.g. the absolute minimum around 1800 and the exceptional warming to the double-peak ed early 20th century maximum, which represents the warmest temperatures in the Late Holocene. A long-term decrease of AN d18 O data does not solely reflect climate cooling but probably also the growth of AN ice cap. Neither a pronounced Medieval Warm Period nor a Little Ice Age could be identified. However, AN proxy records show evidence for several rapid climate changes, e.g. strong warming and cooling events in the 15th and 16th centuries. They indicate considerable shifts in the internal dynamics of the Arctic climate system comprising changes in the atmospheric circulation patterns and accompanied sea ice extent changes. AN d18 O values coincide good with that of the Austfonna ice core (Svalbard), underlining the regional significance of AN ice core data. Variations in the deuterium excess data indicate changes in moisture generation and transport, probably related to changes in the atmospheric circulation patterns and/or sea ice dynamics. |
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