High-Resolution Convective Wet Scavenging Simulations : A Case Study of the Fukushima Daiichi Nuclear Power Plant Accident

Liu, Nuohang and Ge, Baozhu and Su, Xingtao and Chen, Xueshun and Wild, Oliver and Zhang, Yuanchun and Wang, Zhe and Wang, Zifa (2025) High-Resolution Convective Wet Scavenging Simulations : A Case Study of the Fukushima Daiichi Nuclear Power Plant Accident. Journal of Geophysical Research: Atmospheres, 130 (16): e2024JD043. ISSN 0747-7309

Text (Liu_N_AAM_small)
Liu_N_AAM_small.pdf - Accepted Version
Available under License Creative Commons Attribution.
Download (5MB)

Abstract

Abstract Convective precipitation is a key factor for diagnosing convective clouds and the subsequent modeling of the wet scavenging of air pollutants in offline chemical transport models (CTMs). However, a discrepancy exists between the Weather Research and Forecasting model, which uses resolved convection, and CTMs, which rely on a diagnostic convective cloud scheme, in handling high-resolution convective wet scavenging simulations. To explore the uncertainties arising from this disparity, this study focuses on 137Cs, released during the Fukushima Daiichi Nuclear Power Plant accident, as a species with numerous observations compared to other radionuclides and minimal interference from other factors using the NAQPMS model incorporating a physically-based wet deposition module. A diagnostic convective cloud scheme was applied, using a radar composite reflectivity factor (RCRF) of 35 dBZ to identify convective precipitation. Implementing the RCRF diagnosis scheme significantly improved model performance by increasing in-cloud deposition. This enhancement led to a 4648resolution convective wet scavenging using offline CTMs.