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| Titel |
Testing the potential of 10Be in varved sediments from two lakes for solar activity reconstruction |
| VerfasserIn |
Markus Czymzik, Raimund Muscheler, Achim Brauer, Florian Adolphi, Florian Ott, Ulrike Kienel, Nadine Dräger, Michał Słowiński, Ala Aldahan, Göran Possnert |
| Konferenz |
EGU General Assembly 2015
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 17 (2015) |
| Datensatznummer |
250109949
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| Publikation (Nr.) |
 EGU/EGU2015-9902.pdf |
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| Zusammenfassung |
| The potential of 10Be in annually laminated (varved) lake sediments for solar activity
reconstruction is, to date, largely unexplored. It is hypothesized that 10Be contents in
sediments from well-chosen lakes reflect the solar induced atmospheric production
signal. The varved nature of these archives provides the chance to establish solar
activity time-series with very high temporal precision. However, so far solar activity
reconstruction from 10Be in varved lake sediments is hampered due to a lack of detailed
knowledge of the process chain from production in the atmosphere to deposition on
the lake floor. Calibrating 10Be time-series from varved lake sediments against
complementary proxy records from the same sediment archive as well as instrumental
meteorological and solar activity data will allow a process-based understanding of 10Be
deposition in these lakes and a quantitative evaluation of their potential for solar activity
reconstruction.
10Be concentration and flux time-series at annual resolution were constructed for the
period 1983 to 2007 (approx. solar cycles 22 and 23) conducting accelerator mass
spectrometry and varve chronology on varved sediments of Lakes Tiefer See and
Czechowski, located on an east-west transect at a distance of about 450 km in the lowlands of
northern-central Europe. 10Be concentrations vary between 0.9 and 1.8*108atoms/g, with a
mean of 1.3*108atoms/g in Lake Tiefer See and between 0.6 and 1.6*108atoms/g,
with a mean of 1*108atoms/g in Lake Czechowski. Calculated mean 10Be flux is
2.3*108atoms/cm2/year for Lake Tiefer See and 0.7*108atoms/cm2/year for Lake
Czechowski. Calibrating the 10Be time-series against corresponding geochemical μ-XRF
profiles, varve thickness and total organic carbon records as well as precipitation data from
the nearby stations Schwerin for Lake Tiefer See and Koscierzyna for Lake Czechowski and a
neutron monitor record of solar activity suggests (1) a complex interaction of varying
processes influencing 10Be deposition in both lakes and (2) that neither 10Be concentrations
nor fluxes are the most suitable indicator of solar variability alone. Multiple regression
analyses indicate that the combined 10Be concentration and flux time-series account for about
80% (Tiefer See) and 40% (Lake Czechowski) of the variability in the neutron
monitor record, sufficient to reconstruct variability related to the 11-year solar cycle. |
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