Overview of Secondary Ice Production In the Deep Convective Microphysics Experiment (DCMEX)

Secondary ice formation has long been a problem in cloud physics. This affects the radiation properties, precipitation development and the lifetime of mixed-phase clouds.  We conducted multiple flights over the Magdalena Mountain region in New Mexico to provide high-resolution information on the spatio-temporal distribution of ice phase evolution and the linkage between convective cloud thermodynamic and secondary ice processes. A combination of high-resolution cloud spectrometers (including 3VCPI, 2DS, HVPS, and CDP) were used to provide measurements of the evolution of cloud particle and precipitation concentrations, sizes, and morphology. Those data were used to identify and assess primary and secondary ice production (SIP) contributions compared with measured INP concentrations to characterise the frequency of SIP events, where precipitation particles first form and how they interact with cloud dynamics. The initial results suggest that most ice enhancement events in these clouds occurred in the temperature range of -5 °C to -10 °C, while occasionally even larger concentrations were observed between -22.5 °C and -25 °C. The results also show that observed secondary ice in the temperature range from -25 °C to -30 °C was more related to the updraft regions. The next step is to produce more detailed explanations and results by examining these data in conjunction with the cloud thermodynamic background.