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| Titel |
Climate from a 1000-year multiproxy tree-ring record from Forfjorddalen, North Norway |
| VerfasserIn |
Andreas J. Kirchhefer, Giles H. F. Young, Björn E. Gunnarson, Håkan Grudd, Neil J. Loader, Danny McCarroll |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250043871
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| Zusammenfassung |
| The ring-width (RW) chronology of Scots pine (Pinus sylvestris L.) from Forfjorddalen,
Vesterålen archipelago (68Ë 47.5’N, 15Ë 43.5’E) extends back to AD 812. July-August
temperatures are reconstructed back to AD 1100 based on a subset of the RCS-detrended RW
series (Radj2 = 42.0 %). This suggests warm summers persisted during: the Medieval period
1100-1250; from 1750-1850; and from 1915-1955. The latter period being warmer than the
Medieval Warm Period. Cool summers apparently prevailed during 1375-1475 and
1600-1650.
From a subset of these trees we also analysed maximum latewood density (MXD) and
stable carbon isotopes (δ13C), both also being strongly correlated with July-August
temperatures (r = 0.75 and 0.58, resp.). However, MXD tends to integrate temperatures over a
broader time window than ring-widths, while δ13C should more accurately reflect sunshine
than temperature. These factors may help to explain divergences seen between these
individual proxy records.
The three records run reasonably in parallel during 1100-1325 and since 1775. However,
from 1325-1450, MXD values are high in contrast to RW and δ13C, indicating a
prolonged Medieval Warm Period of more oceanic, cloudy character. During the
period from (1525)1600-1700, δ13C has consistently higher values than MXD and
RW, respectively, indicating cool but sunny conditions during this period of the
Little Ice Age. Low values of MXD and δ13C suggest that at the coast of North
Norway, the summers of 1000-1100 were as cool as during the late 19th century. |
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