AAAR 31st Annual Conference
October 8-12, 2012
Hyatt Regency Minneapolis
Minneapolis, Minnesota, USA
Abstract View
An Intercomparison of Airborne Aerosol Inlet Performances During ICE-T (2011) campaign
Arash Moharreri, Lucas Craig, David C. Rogers, SURESH DHANIYALA, Clarkson University
Abstract Number: 523 Working Group: Instrumentation and Methods
Abstract There are several different designs of aerosol inlets being used by researchers for aerosol sampling from aircraft platforms. While each inlet design is intended to provide a suitable sample for its corresponding instrument, knowledge of their relative efficiency in sampling particles must be known prior to any successful intercomparison of their results. As a simple measure of the relative performance of the different instruments, the total particle concentration (or CN) from different inlets can be compared under different flight and atmospheric conditions. Since most aerosol inlets have cut-sizes greater than 1 micron, and the total particle number concentrations are often dominated by sub-micron particles, the CN intercomparison provides a first measure of inlet measurement consistency. Such an intercomparison is particularly critical in determining the relative performance of inlets in cloud systems. The high speed impaction of ice particles and liquid droplets on the surfaces of the aircraft probes/inlets results in the generation of artifact particles that contaminate aerosol samples to extents that differ with inlet designs. During the ICE-T campaign (2011), three aerosol inlet designs were installed on the NSF/NCAR C-130 aircraft by Clarkson University and NCAR/RAF: BASE (Blunt-body Aerosol Sampler), HiCAS (High-speed Cross-flow Aerosol Sampler), and two SMAIs (Sub-Micron Aerosol Sampler – one operated by Clarkson and the other one by RAF). Analysis of total CN data from the inlets, suggests that the BASE samples are the least contaminated by artifact particles when sampling in cold clouds. The BASE performance, however, demonstrates a tractable dependence on phase, size and habit of cloud particles present. In warm clouds, the SMAI operated by Clarkson team showed the best performance in terms of avoiding the sampling artifacts associated with the droplet splashing phenomenon. Complete details of the different inlet designs and their measurements and relative performance will be discussed.