Gergely successfully defended his PhD proposal on April 28, 2011.

TITLE:
Polarized Imaging Nephelometer Development and Applications for Field and Aircraft

ABSTRACT:
The goal of this research project is to analyze, build, characterize and demonstrate a new airborne instrument for measuring aerosol phase matrix: the LACO/UMBC polarized imaging nephelometer (PI-Neph). We have built a laboratory prototype of this imaging nephelometer concept and the robust airborne version is under construction, funded by the CALIPSO mission (Cloud-Aerosol Lidar and Infrared Pathfinder Satellite Observation) under the DEVOTE project (Development and Evaluation of satellite ValidatiOn Tools by Experimenters).

Project success will provide airborne capability to measure phase matrix elements of aerosol particles with an unprecedented angular range at multiple wavelengths. The PI-Neph measurements during the DEVOTE campaign will be analyzed to provide a pilot study showing comparison to RSP (Research Scanning Polarimeter) and HSRL (High Spectral Resolution Lidar) retrievals and to other in situ measurements, especially integrating nephelometers.

Further characterization and testing will prepare the instrument for future aircraft campaigns serving the validation of CALIPSO and RSP retrievals, potentially other aerosol remote sensing instruments and eventually the future ACE mission (Aerosol/Cloud/Ecosystems). A series of in situ experimental flights and ground experiments will enable the use of resultant data for comparison to the new generation of remote sensors. The in situ measurements of aerosol light scattering will enable retrievals of aerosol size and shape distribution and refractive index, which in turn can be compared to lidar, polarimeter or combined polarimeter-lidar retrievals.

Laboratory and/or field studies of polarized phase function of aerosols versus relative humidity will aid in remote sensing of aerosol fields near clouds to help uncover the principles of the aerosol indirect effect on Earth’s climate. The next couple of years of this PhD work will provide the essential bridge between the development, verification and science applications of the PI-Neph, moving toward a proven satellite sensor calibration / validation capability.