Modeling Aerosol Microphysics in Ice Giant Atmospheres 

The atmospheric composition of Uranus and Neptune provides crucial insights into their origins, evolution, and has broad implications for exoplanetary science. Clouds and hazes play a pivotal role in these atmospheres, influencing radiative transfer, dynamics, and chemistry while also serving as tracers for wind patterns. Methane and Hydrogen Sulfide clouds potentially dominate the troposphere, whereas the stratosphere contains hazes likely composed of complex hydrocarbons. These aerosol layers develop and evolve through processes such as nucleation, condensation, coagulation, and evaporation. Despite their significance, the microphysics underlying these interactions and the interplay between distinct aerosol layers remain understudied. Our research utilizes the 1D Community Aerosol and Radiation Model for Atmospheres (CARMA) to simulate the aerosol distribution and processes within Uranus’s and Neptune’s atmospheres. By varying a number of model parameters (e.g. size and vertical distribution of condensation nuclei, contact angles, atmospheric mixing, etc.), this work provides a detailed framework to study the sensitivity of the clouds to material properties and atmospheric conditions. This study not only enhances our understanding of ice giant atmospheres and informs future mission design, but also provides a foundation for interpreting observations of exoplanetary atmospheres.