Deciphering Pluto's Haze: How a Solar-Powered Vapor-Pressure Plume Shapes Its Bimodal Particle Size Distribution

Combining findings from New Horizons’ suite of instruments reveals a bimodal haze particle distribution within Pluto’s atmosphere, which haze models have not been able to reproduce. We employ the photochemical and microphysics KINAERO model to simulate seasonal cycles and their impact on the haze distribution. We find that the smaller spherical particle mode can be generated through photochemistry and coagulation, while the larger aggregate mode are formed by surface volatile deposits sublimating and subsequently lofting such particles upwards.