<b>Phase Separation of an Incipient Isotropic Water Vapor Phase from Water Ice for Ice Nucleated Homogeneously versus Heterogeneously</b>

We consider an ice molecule coexisting with an incipient sublimating water vapor phase, with the ice molecule constituting the anisotropic phase and the water vapor phase corresponding to the isotropic phase by employing a Flory lattice model describing phase separation in a system of rigid rods with axial ratios x having a most probable size distribution. The same model is used to describe phase separation in systems of water molecules [2)] driven by the presence of rods with infinite axial ratios that interact with the hydrogen bonds connecting the water molecules, with these infinite axial ratio rods corresponding to Dirac strings or magnetic monopoles. The cases that the parent ice phase was generated by homogeneous nucleation and by heterogeneous nucleation are both considered. In the latter case, the fate of the nucleating particles in the ice phase following generation of the isotropic phase is considered and shown to have potential consequences for current proposals to address global warming by introducing ice nucleating particles into the Earth’s tropopause.