Investigating Dual Character of Atmospheric Ammonia on Particulate NH4NO3: Reducing Evaporation Versus Promoting Formation

This dataset supports a study on the dual role of atmospheric ammonia (NH₃) in both promoting the formation and suppressing the evaporation of particulate ammonium nitrate (NH₄NO₃) in a tropical coastal atmosphere. It includes high-resolution observations of NH₃, HNO₃*, PM₂.₅ ionic components, particle size distributions, and carbonaceous species. The data reveal persistent gas-particle partitioning disequilibrium and distinct seasonal formation mechanisms, providing a robust basis for thermodynamic analysis and source apportionment of nitrate aerosols.