Atmospheric impact of quasiliquid layers on ice surfaces

Abstract

[1] We present a fully thermodynamically constrained model to calculate the thickness of the quasiliquid layer on ice surfaces and apply this model to atmospherically relevant situations to calculate the quasiliquid thickness and volume for ice aerosols and snow pack. These volumes are comparable to the liquid volumes present in a representative liquid-droplet cloud. The pure water calculations represent conservative lower bounds to the volume possible from more complex solutions. Incorporation of solution chemistry into the model demonstrates both the effect played by impurities when studying this phenomenon and how the formation of the quasiliquid layer concentrates impurities on the ice surface.

An adsorption model of insoluble particle activation: Application to black carbon

“…In this paper we calculate and refer to the free energy difference, DG, as shown in equation (3). Although this is not the usual form of the c constant we have had considerable success with this approximation in modeling the properties of the so-called quasiliquid phase in a number of systems [Henson and Robinson, 2004] with ice a particular example [Voss et al, 2005].…”

Measurement of acidic ions and their qualitative effects on snow crystal morphology and the quasi-liquid layer

“…It is well known that addition of an ionizable solute will decrease the melting point of the solvent relative to its pure state. It is proposed that by introducing varying amounts of gaseous acetic acid (AA) into a crystal growth chamber the AA uptake into the growing crystal will alter the QLL thickness in a controlled manner (Wettlaufer, 1999;Cho et al, 2002;Voss et al, 2005;McNeill et al, 2006), allowing observation of changes in morphology transition temperatures. Any shift in transition temperature, as a function of AA mole fraction, could thus be Fig.…”

Gas phase acetic acid and its qualitative effects on snow crystal morphology and the quasi-liquid layer

“…3 shows the results of a molecular dynamics simulation for the QLL in pure water ice. Though the thickness of the QLL at various temperatures, and its temperature of onset, remain debatable (Bluhm et al, 2002;, it is well known that the thickness decreases with decreasing temperature Sadtchenko and Ewing, 2003;Ewing, 2004;Voss et al, 2005), differs depending on the ice crystal's facet (Kuroda and Lacmann, 1982;Furukawa et al, 1987a, b;Furukawa, 1996, 1997a;Furukawa, 1997;Carignano et al, 2005), and is highly dependent on the technique used (Wettlaufer, 1999;). These differences in QLL thickness, and the physical shape of the crystal, cause different rates of crystal facet growth and thereby change the crystal's morphology as a function of temperature (Kuroda and Lacmann, 1982;Carignano et al, 2005;Libbrecht, 2005b).…”

“…It is well known that addition of an ionizable solute will decrease the melting point of the solvent relative to its pure state. It is proposed that by introducing varying amounts of gaseous acetic acid (AA) into a crystal growth chamber the AA uptake into the growing crystal will alter the QLL thickness in a controlled manner (Wettlaufer, 1999;Cho et al, 2002;Voss et al, 2005;McNeill et al, 2006), allowing observation of changes in morphology transition temperatures. Any shift in transition temperature, as a function of AA mole fraction, could thus be associated with a change in QLL thickness.…”