On the Effectiveness of Interarrival Time Algorithms for Filtering Shattering Artifacts in Cloud Particle Probes

Shattering is a serious problem for airborne characterization of the microphysical properties of ice clouds. Ice particles may impact on the forward parts of the probe, shatter into small fragments and bounce towards the sample area. Special algorithms have been developed to identify and filter out these shattering artifacts. The interarrival time algorithm is based on the assumption that, relative to unaffected intact particles, shattered fragments form spatial clusters that exhibit a 'short' interarrival time between particles as they pass through the probes sample volume. Interarrival time algorithms are considered to be the most efficient technique for segregation of shattering artifacts and intact particles. The present study assesses the limitations and efficiency of interarrival time algorithms based on the simultaneous measurements of 2D probes with the standard and antishattering K-tips collected during the Airborne Icing Instrumentation Experiment (AIIE). It is demonstrated that the efficiency of the algorithm depends on the particle size, concentration and habit. Based on numerical simulation it is also shown that interarrival time algorithms cannot eliminate all shattering artifacts. Some improvements of the algorithm are discussed.