Immersion freezing, which is the focus of our study, occurs when freezing is initiated by an INS immersed in an aqueous droplet and can dominate ice formation in mixed-phase clouds . INSs allow for the formation of ice crystals in clouds at warmer temperatures and lower water vapor pressures than those required for homogenous ice nucleation. As a result, INSs affect cloud properties and therefore the climate via effects on the hydrological cycle and Earth's radiative properties .