A global radon flux map based on Zhang et al. (2011)

This repository includes data and scripts to generate a global radon flux map. The global map was put together using regional fluxes reported recently in the literature. More details can be found in Zhang et al. (2011)

Script

• script/make_rnemis_run.csh : c-shell script to call rnemis.ncl
• script/rnemis.ncl : NCL script to create the global radon flux data by merging regional and global radon flux maps. This script will call CDO to remap data to target resolutions.
• Description:
  • E0: WCRP1995 emission
  • E1: WCRP1995 magnitude with Schery1998 time information
  • E2: Schery1998 Schery et al. (1998) scaled by 1.6
  • E3: merged emission based on Zhang et al. ACP2011 (china, europe, russia, usa, aus, schery1998, schery2004_ocean)

Data

• rnemis_ECHAM : radon flux data prepared for the ECHAM model (T21-T159)
• rnemis_r360x180 : radon flux data on 1°x1° grid
• rnemis_r720x360 : radon flux data on 0.5°x0.5° grid

Evaluation

The new global radon emission map represents better regional details and seasonal variation. The simulated radon activity concentration using the new global flux is evaluated against surface radon measurements at 51 locations. Results show that the global model ECHAM5 can reasonably reproduce the variations of surface radon concentrations observed at various locations. On the whole, the newly compiled emission map leads to better results compared to the WCRP1995 protocol and the widely used SW1998 map. The merged map is not only helpful for this study, but probably also useful for other researchers working on numerical modelling of radon transport and the transport and deposition processes of 210Pb.

Reference

• 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, https://doi.org/10.5194/acp-11-7817-2011, 2011.
• Szegvary, T., Leuenberger, M. C., and Conen, F.: Predicting terrestrial 222Rn flux using gamma dose rate as a proxy, Atmos. Chem. Phys., 7, 2789-2795, https://doi.org/10.5194/acp-7-2789-2007, 2007.
• Griffiths, A. D., Zahorowski, W., Element, A., and Werczynski, S.: A map of radon flux at the Australian land surface, Atmos. Chem. Phys., 10, 8969-8982, https://doi.org/10.5194/acp-10-8969-2010, 2010.
• Schery, S. D. and Wasiolek, M.A., 1998. Modeling radon flux from the earth’s surface. Radon and Thoron in the human environment, pp.207-217.
• Schery, S. D., and S. Huang (2004), An estimate of the global distribution of radon emissions from the ocean, Geophys. Res. Lett., 31, L19104, doi:10.1029/2004GL021051.
• Zhuo, W., Guo, Q., Chen, B. and Cheng, G., 2008. Estimating the amount and distribution of radon flux density from the soil surface in China. Journal of environmental radioactivity, 99(7), pp.1143-1148.

Acknowlegement

Original regional flux maps were provided by Dr. W. Zhuo (China), Dr. A. D. Griffiths (Australia), Dr. T. Szegvary and Dr. F. Conen (Europe, Russia, and USA). Global radon flux used for other regions were provided by Dr. S. D. Schery.