Initial Ice Microparticle Sublimation Measurements from the Levitating Upper-Tropospheric Environmental Simulator (LUTES)

Abstract

nitial ice particle sublimation data are presented from the new Levitating Upper-Tropospheric Environmental Simulator (LUTES) at The College of New Jersey. This experimental system mimics the conditions of a typical cirrus cloud in order to evaluate the phase-change kinetics of single ice particles. These ice particles are charged and then trapped in a levitating electrodynamic balance where they can be observed as they sublimate in a subsaturated atmosphere. Levitation and sublimation take place within a vacuum chamber, which is contained in a freezer at a temperature of ?40° to ?80°C and is capable of a reduced pressure of 10 mb. The sublimation rates of the ice particles are observed at a variety of temperature, humidity, and pressure conditions and are compared to sublimation rates predicted by particle-scale diffusion models. Initial measurements suggest that the diffusion models are capturing the essential sublimation behavior of the particles, but further measurements promise to inform lingering questions about the fundamental thermodynamics and surface processes of sublimating and growing ice particles under cirrus conditions.