With the Minamata Convention on Mercury coming into effect in 2017, all parties are required to periodically evaluate the effectiveness of its implementation using available scientific, environmental, technical, financial, and economic data. The hemispheric version of CMAQ-newHg-Br v2 (H-CMAQ-newHg-Br), which incorporates a theory-based gas-particle partitioning scheme for gaseous oxidized mercury (GOM) and the most up-to-date mercury redox chemical mechanism (Wu et al., 2024), is a potential modeling tool for this task. In the present study, H-CMAQ-newHg-Br was developed from extending the regional model to a hemispheric domain and was applied to simulate atmospheric mercury cycling in the Northern Hemisphere for the year of 2019. The model was evaluated through comparison of simulated and observed concentrations of gaseous elemental mercury (GEM) and particulate bound mercury (PBM) and deposition fluxes of total mercury at monitoring locations worldwide as well as intercomparison with the Danish Eulerian Hemispheric Model (DEHM) and global chemical transport models. The advantages, uncertainties, and applications of H-CMAQ-newHg-Br will be discussed. Our results demonstrate that hemispheric H-CMAQ-newHg-Br would be a promising tool for evaluating the effectiveness of the Minamata Convention.

¹ SUNY-ESF, Syracuse, NY

² Aarhus University, Aarhus, Denmark

³ U.S. Environmental Protection Agency, RTP, NC

* Corresponding author: lwu127@esf.edu