Presentation Information
[U08-05]A Next-Generation Framework for Global Mercury Cycling in a Fully Coupled Earth System Model
*Yanxu Zhang1, Peng Zhang2, Tengfei Yuan1, Dong Peng2, Mao Mao1, Shaojian Huang1 (1.Tulane University, 2.Nanjing University)
Keywords:
Mercury,Earth System Model,CESM,Global Biogeochemistry Cycling
Mercury, a globally distributed legacy contaminant, poses persistent risks to ecosystems and human health through long-range transport, bioaccumulation, and trophic transfer. Mercury cycling is a complex system influenced by both natural processes and human activities, spanning multiple environmental media, and regulated by biogeochemical processes. Traditional single-compartment models or offline frameworks cannot consistently represent key fluxes, reservoir evolution, and feedback within a unified system; thus, an Earth system-scale, process-consistent mercury cycle model is urgently needed. Within the Community Earth System Model (CESM), we explicitly represent emissions, chemical transformation, transport, and deposition of speciated atmospheric mercury in the atmospheric component; characterize key processes such as vegetation uptake, soil re-emission, and wildfire perturbations in the land component; incorporate mercury transformation, air-sea exchange, and the biological pump in the ocean component; and represent terrestrial inputs and nearshore transport through the riverine component. These components are coupled via the CESM coupler to enable online exchange of fluxes, ultimately achieving fully coupled atmosphere-land-ocean mercury simulations. This framework provides an integrated modeling system that simultaneously captures the coupled evolution of global mercury sources, sinks, and reservoirs, thereby offering a quantitative basis for attribution of historical changes, projection of future scenarios, and evaluation of emission-control effectiveness.