Photoreduction of mercuric bromides in polar ice.

ABSTRACT: In the polar regions, which are vulnerable receptors of mercury pollution, atmospheric mercury depletion events (AMDEs) efficiently convert elemental mercury (Hg(0)) into oxidized mercury (Hg(II)) via bromine oxidation. Hg(II) subsequently deposits onto snow and sea ice. While field observations have shown that a large percentage of deposited mercury is re-emitted from the ice to the atmosphere by a photoinduced process, the fundamental photochemistry that drives the re-emission process remains unknown. Here, using multiconfigurational quantum chemistry, we find that the photoreduction of HgBr₂, HgBr₃^-, and HgBr₄^2- in ice is more efficient than in the gas phase. This results from the influence of water molecules on the molecular geomet

SUBMITTER: Carmona-Garcia J 

PROVIDER: S-EPMC11912456 | biostudies-literature | 2025 Mar

REPOSITORIES: biostudies-literature