AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Modeling the Relative Contributions of Secondary Ice Formation Processes to Ice Crystal Number Concentrations within Mixed-Phase Clouds
Sylvia Sullivan, Corinna Hoose, ATHANASIOS NENES, Georgia Institute of Technology
Abstract Number: 515 Working Group: Aerosols, Clouds, and Climate
Abstract In-cloud measurements of ice crystal number concentration can be three or four orders of magnitude higher than the in-cloud ice nuclei concentration. A number of secondary ice formation processes after initial nucleation have been proposed, but the relative importance and even the exact mechanisms of these processes are still unknown. In this work, a multiple-bin parcel model is constructed to estimate possible ice enhancement, both its bounds and its value for different cloud types, due to rime-splintering and break-up upon graupel-graupel collision. The model also includes ice aggregation and droplet coalescence, ice hydrometeor non-sphericity as in Jensen and Harrington, 2015, and a time delay formulation as in Yano and Phillips, 2011. The maximum contribution from break-up, the computational cost of non-sphericity, and the effect of varying time delays are discussed. Finally, the model behavior under various limits and simplifications is considered.