Abstract:By using the probe of DMT (Droplet Measurement Technologies), the aircraft icing in nonprecipitation clouds on 12 April in 2014 over Yichang and its surrounding areas were probed. The vertical distributions show that the number concentrations of CAS (Cloud Aerosol Spectrometer), CIP (Cloud Imaging Probe) and PIP (Precipitation Imaging Probe) are greater than 300 cm-3, 1 cm-3 and 10-5 cm-3, respectively. The maximum median diameters are 3 μm, 89 μm and 1389 μm, respectively. The spectral distribution shows that the gravitational collision and riming processes result in forming a wider spectra at 3650 m, while relatively narrow below 3650 m, where particles grow mainly depend on condensation process, big cloud particles and ice crystals are dropping from upper levels. The horizontal probe shows that the number concentrations of CAS and CIP at 3350 m are greater than those at 3650 m, while the number concentration of PIP, the median diameter and the maximum median diameter are opposite. The time series of horizontal probe show that the number concentration and the median diameter at 3350 m have an inverse relationship, and the number concentration and the median diameter of big cloud particles and ice crystals are fluctuant.