Limits in our understanding of concerning cloud-aerosol interactions, and particularly the role of atmospheric aerosols serving as cloud condensation nuclei and their ultimate influence on solar and infrared radiation passing through earth's atmosphere, remain a significant source of uncertainty in the prediction of long-term global climate trends. This research will serve to design and develop an instrument to enable real-time measurement of aerosol hygroscopic growth factors suitable for operation aboard research aircraft. This instrument, called the Real-time Hygroscopic Differential Mobility Spectrometer (RH-DMS), will permit accurate sizing and characterization of aerosols both within and outside cloud systems over a diameter range of observed particle diameters.
The intellectual merit of this effort centers on efforts to minimize uncertainties in cloud interactions with both short- (visible) and long-wave (infrared) radiation, and will employ innovative components including an interstitial inlet for artifact-free sampling of aerosol within clouds, a high-resolution differential mobility analyzer to distinctly quantify particle sizes, and coupling with a high-resolution optical particle sizer and electrical mobility spectrometer to assess the hygroscopic growth potential over a wide range of aerosol sizes (10-500 nm). Broader impacts will come through enhanced measurement capabilities aboard a research aircraft, and improved understanding of both the local behavior and global impacts of clouds in the context of both naturally-occurring and anthropogenic aerosols relevant to earth's changing climate. Related educational benefits will include graduate student education and be integrated with the lead investigator's existing K-12 outreach activities.