Structure and water attachment rates of ice in the atmosphere: role of nitrogen

Abstract

In this work we perform computer simulations of the ice surface in order to elucidate the role of nitrogen in the crystal growth rates and crystal habits of snow in the atmosphere.

Premelting of ice adsorbed on a rock surface

“…This could for instance influence the escape of greenhouse gas molecules from melting ice. [100,101] It has been speculated that a liquid-vapour surface could help nucleate ice. [102] Here, and in previous work [8], we show that ice has a propensity to grow up to about 3.6 nm close to the liquid-vapour surface, since this slightly stabilises the system with respect to the formation of two distant ice-liquid and liquid-vapour interfaces.…”

Rounded Layering Transitions on the Surface of Ice

“…To prepare the system in the solid/vapor coexistence region, we place an ice slab of either 1280 or 5120 molecules in vaccuum. Performing canonical Molecular Dynamics simulations [38] with GROMACS, the system attains two phase coexistence in a few nanoseconds and an equilibrated premelting film is formed spontaneously [18,[39][40][41] (Supplementary Material). Previously, computer simulation evidence for a layering transition of the TIP4P/Ice model has been discussed in terms of the density profile ρ(z) of the H 2 O molecules as a function of the perpendicular distance, z to the interface [15].…”

“…A more detailed description of layering phenomena in terms of density profiles is afforded by identifying liquid-like and solid-like environments [42,43]. Using the q6 order parameter [42] allows us to plot the density of liquid-like and solid-like molecules, and identify features that are specific to the premelting layer [39,41,44].…”

Studying Ice with Environmental Scanning Electron Microscopy

“…However, recent computer simulations point out that nitrogen, the main component of the atmosphere, has very low adsorption energy on ice. However, it seems that the density of nitrogen found in the atmosphere may slow down the water molecules directed to the surface of ice [ 11 ]. It seems worthwhile to note that the first detailed visualization of the formation of an ice grain boundary in the ESEM was claimed in 2011 [ 91 ].…”

“…In recent years, with the rapid advancement in instrumentation as well as simulation capabilities, important advances in the process of understanding of ice nucleation and ice dynamics emerged [ 3 , 8 , 9 , 10 , 11 , 12 ]. One of the main techniques applied today in the investigation on the topic is environmental scanning electron microscopy, ESEM.…”