title: Homogeneous freezing of water starts in the subsurface.
abstract: Molecular dynamics simulations of homogeneous ice nucleation in extended aqueous slabs show that freezing preferentially starts in the subsurface. The top surface layer remains disordered during the freezing process. The subsurface accommodates better than the bulk the increase of volume connected with freezing. It also experiences strong electric fields caused by oriented surface water molecules, which can enhance ice nucleation. Our computational results shed new light on the experimental controversy concerning the bulk vs surface origin of homogeneous ice nucleation in water droplets. This has important atmospheric implications for the microphysics of formation of high altitude clouds.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, and Center for Complex Molecular Systems and Biomolecules, Flemingovo nam. 2, 16610 Prague 6, Czech Republic.
authors.forename: Lubos
authors.initials: L
authors.lastname: Vrbka
authors.forename: Pavel
authors.initials: P
authors.lastname: Jungwirth