A study of particle dry deposition parameterizations in an atmospheric radioactive preparedness model: Application to the Chernobyl case

• Published in: Journal of hazardous materials 2024-08, Vol.474, p.134638, Article 134638
• Main Authors: Berge, Erik, Ulimoen, Magnus, Dobler, Andreas, Kashparov, Valery Alexandrovich, Klein, Heiko, Lind, Ole Christian
• Format: Article
• Language: English
• Subjects: Atmospheric dispersion models; Chernobyl; Dry deposition; Preparedness modelling; Radioactive particles
• ISSN: 0304-3894; 1873-3336; 1873-3336
• DOI: 10.1016/j.jhazmat.2024.134638

Parameterization of dry deposition is key for modelling of atmospheric transport and deposition of radioactive particles. Still, very simple parameterizations are often encountered in radioactive preparedness models such as the SNAP model (SNAP=Severe Nuclear Accident Program) of the Norwegian Meteorological Institute. In SNAP a constant dry deposition velocity (=0.2 cm/s) neglecting aerodynamic and surface resistances, is presently used. Therefore, two new dry depositions schemes (the Emerson scheme and the EMEP (European Monitoring and Evaluation Programme) scheme) have been implemented in SNAP to evaluate the benefits of including aerodynamic and surface resistances codes with respect to model prediction skills. The three dry deposition schemes are evaluated using 137Cs total deposition from soil sample data (n = 540) for a 60 km radial zone out from the Chernobyl Nuclear Power Plant (ChNPP) collected during the months after the accident. The present study capitalizes on high resolution meteorological data (2.5 km horizontal resolution), a detailed land-use data set with 273 sub-classes and the hitherto most comprehensive source term description for the Chernobyl accident. Based on our findings it is recommended to replace the present simple SNAP scheme with the Emerson or EMEP dry deposition scheme. [Display omitted] •New dry deposition codes evaluated for atmospheric dispersion modelling of 137Cs.•Comprehensive meteorological and land-use data as well as source term for Chernobyl accident.•Validation of model prediction skills using 540 soil sample data from near Chernobyl.•Advanced dry deposition schemes improved predictions compared to more simplistic approach.•Reduced dry deposition near Chernobyl and increased long-range transport with new schemes.