Abstract
JOURNAL OF GEOPHYSICAL RESEARCH,
VOL. 111,
D21105,
6 PP., 2006
doi:10.1029/2005JD006764
Evidence for climate modulation of the 10Be solar activity proxy
Australian Government Antarctic Division, Kingston, Tasmania, Australia
Australian Government Antarctic Division, Kingston, Tasmania, Australia
Australian Government Antarctic Division, Kingston, Tasmania, Australia
Australian Government Antarctic Division, Kingston, Tasmania, Australia
Australian National Tandem Accelerator for Applied Research (ANTARES) AMS, Australian Nuclear Science and Technology Organisation, Menai, New South Wales, Australia
Institute of Antarctic and Southern Ocean Studies, University of Tasmania, Hobart, Tasmania, Australia
We used a snow pit record in conjunction with detailed snow accumulation data and oxygen isotope records to examine atmospheric transport and deposition effects on 10Be at Law Dome, Antarctica. Data from an adjacent automatic weather station was used to date the record at snowfall event-scale resolution. In contrast to prior ice core studies in Antarctica, the snow pit record is of a sufficiently short duration (∼1 year) that 10Be fluctuations reflect mainly atmospheric transport processes rather than solar modulation of production. Elevated concentrations of 10Be were found in the late austral summer and early autumn snow, synchronous with the seasonal increase in stratospheric aerosols at Antarctic stations. A significant (P < 0.01) anticorrelation of 10Be with δ 18O occurs at the snowfall event scale. Fractionation of water isotopes at Law Dome is controlled by local and regional processes, specifically transport and local temperature. The anticorrelation seen here implies that 10Be concentration was reduced in snow from warmer air masses (characterized by less negative δ 18O). There is potential for confounding solar modulation with climatic modulation if at sites such as this one, warmer meteorological influences may be associated with reduced 10Be concentrations. Quantification of the significance of this effect for the longer-term 10Be record will require analysis of longer 10Be records from different sites.
Received 13 October 2005; accepted 22 June 2006; published 7 November 2006.
Citation: (2006), Evidence for climate modulation of the 10Be solar activity proxy, J. Geophys. Res., 111, D21105, doi:10.1029/2005JD006764.
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