Radon activity in the lower troposphere and its impact on ionization rate: a global estimate using different radon emissions 1Max Planck Institute for Meteorology, Hamburg, Germany
03 Aug 2011
2Cooperative Institute for Research in Environmental Sciences (CIRES), University of Colorado, Boulder, Colorado, USA
3Institute of Radiation Medicine, Fudan University, Shanghai, China
4Australian Nuclear Science and Technology Organisation, Lucas Heights NSW 2234, Australia
5Federal Office for Radiation Protection (BfS), Salzgitter, Germany
6Laboratoire des Sciences du Climat et de l'Environnement, IPSL, CEA, UVSQ, CNRS, Gif-sur-Yvette, France
7Centre for Isotope Research, University of Groningen, Groningen, The Netherlands
8South African Weather Service, Stellenbosch, South Africa
9NOAA Earth System Research Laboratory (ESRL), Boulder, Colorado, USA
*now at: Pacific Northwest National Laboratory, Richland, Washington, USA
Received: 16 October 2010 – Published in Atmos. Chem. Phys. Discuss.: 28 January 2011 Abstract. The radioactive decay of radon and its progeny can lead to
ionization of air molecules and consequently influence aerosol
size distribution. In order to provide a global estimate of
the radon-related ionization rate, we use the global
atmospheric model ECHAM5 to simulate transport and decay
processes of the radioactive tracers. A global radon emission
map is put together using regional fluxes reported recently in
the literature. Near-surface radon concentrations
simulated with this new map compare well with measurements.
Revised: 15 July 2011 – Accepted: 01 August 2011 – Published: 03 August 2011
Radon-related ionization rate is calculated and compared to
that caused by cosmic rays. The contribution of radon and its
progeny clearly exceeds that of the cosmic rays in the mid-
and low-latitude land areas in the surface layer.
During cold seasons, at locations where high concentration of sulfuric acid gas
and low temperature provide potentially favorable conditions for nucleation,
the coexistence of high ionization rate may help
enhance the particle formation processes. This suggests that it is probably
worth investigating the impact of radon-induced ionization
on aerosol-climate interaction in global models.
Citation: Zhang, K., Feichter, J., Kazil, J., Wan, H., Zhuo, W., Griffiths, A. D., Sartorius, H., Zahorowski, W., Ramonet, M., Schmidt, M., Yver, C., Neubert, R. E. M., and Brunke, E.-G.: Radon activity in the lower troposphere and its impact on ionization rate: a global estimate using different radon emissions, Atmos. Chem. Phys., 11, 7817-7838, doi:10.5194/acp-11-7817-2011, 2011.