Journal cover Journal topic
Atmospheric Chemistry and Physics An interactive open-access journal of the European Geosciences Union
Journal topic

Journal metrics

Journal metrics

  • IF value: 5.668 IF 5.668
  • IF 5-year value: 6.201 IF 5-year
    6.201
  • CiteScore value: 6.13 CiteScore
    6.13
  • SNIP value: 1.633 SNIP 1.633
  • IPP value: 5.91 IPP 5.91
  • SJR value: 2.938 SJR 2.938
  • Scimago H <br class='hide-on-tablet hide-on-mobile'>index value: 174 Scimago H
    index 174
  • h5-index value: 87 h5-index 87
Volume 8, issue 10
Atmos. Chem. Phys., 8, 2797-2809, 2008
https://doi.org/10.5194/acp-8-2797-2008
© Author(s) 2008. This work is distributed under
the Creative Commons Attribution 3.0 License.
Atmos. Chem. Phys., 8, 2797-2809, 2008
https://doi.org/10.5194/acp-8-2797-2008
© Author(s) 2008. This work is distributed under
the Creative Commons Attribution 3.0 License.

  29 May 2008

29 May 2008

Modeling cosmogenic radionuclides 10Be and 7Be during the Maunder Minimum using the ECHAM5-HAM General Circulation Model

U. Heikkilä1, J. Beer1, and J. Feichter2 U. Heikkilä et al.
  • 1EAWAG, Dübendorf, Switzerland
  • 2Max-Planck Institute for Meteorology, Hamburg, Germany

Abstract. All existing 10Be records from Greenland and Antarctica show increasing concentrations during the Maunder Minimum period (MM), 1645–1715, when solar activity was very low and the climate was colder (little ice age). In detail, however, the 10Be records deviate from each other. We investigate to what extent climatic changes influence the 10Be measured in ice by modeling this period using the ECHAM5-HAM general circulation model. Production calculations show that during the MM the mean global 10Be production was higher by 32% than at present due to lower solar activity. Our modeling shows that the zonally averaged modeled 10Be deposition flux deviates by only ~8% from the average increase of 32%, indicating that climatic effects are much smaller than the production change. Due to increased stratospheric production, the 10Be content in the downward fluxes is larger during MM, leading to larger 10Be deposition fluxes in the subtropics, where stratosphere-troposphere exchange (STE) is strongest. In polar regions the effect is small. In Greenland the deposition change depends on latitude and altitude. In Antarctica the change is larger in the east than in the west. We use the 10Be/7Be ratio to study changes in STE. We find larger change between 20° N–40° N during spring, pointing to a stronger STE in the Northern Hemisphere during MM. In the Southern Hemisphere the change is small. These findings indicate that climate changes do influence the 10Be deposition fluxes, but not enough to significantly disturb the production signal. Climate-induced changes remain small, especially in polar regions.

Publications Copernicus
Download
Citation
Share