Assessing the global contribution of marine aerosols, terrestrial bioaerosols, and desert dust to ice-nucleating particle concentrations

Aerosol–cloud interactions, particularly ice processes in mixed-phase clouds (MPCs), remain a key source of uncertainty in climate change assessments. This study introduces state-of-the-art laboratory-based parameterizations into a global chemistry–transport model to investigate the contributions of mineral dust (specifically K-feldspar and quartz), marine primary organic aerosol (MPOA), and terrestrial primary biological aerosol particles (PBAPs) to ice-nucleating particles (INPs) in MPCs. The model suggests that INPs originating from PBAPs (INP_PBAP) are the primary source of INPs at low altitudes between −10 and −20 °C, particularly in the tropics, with a pronounced peak in the Northern Hemisphere (NH) during the boreal summer. INP_PBAP contributes over 40 % of the total simulated INP column burden at midlatitudes. Dust-derived INPs (INP_D) are prominent at high altitudes across all seasons, dominating at temperatures below −20 °C, and they constitute over 89 % of the INP average column burden at high latitudes in the NH and about 74 % at high latitudes in the Southern Hemisphere (SH). MPOA-derived INPs (INP_MPOA) prevail in the SH at low altitudes, particularly at subpolar and polar latitudes for temperatures above −20 °C, where they represent between 17 % and 36 % of the INP column population, depending on the season. When evaluated against available global observational INP data, the model achieves its highest predictability across all temperature ranges when both INP_D and INP_MPOA are included as independent INP sources. The addition of INP_PBAP does not enhance the model's ability to reproduce the available observations; however, INP_PBAP remains a key contributor to warm-temperature ice-nucleation events. Therefore, consideration of dust, marine aerosol, and terrestrial bioaerosols as distinct INP species is required to simulate ice nucleation in climate models.