Determination of Marine Aerosol Properties Using a Bistatic Nephelometer
Abstract
The long term goal is to characterize aerosols remotely in the marine atmospheric boundary layer (MABL) based on instruments and analytic methods that use angle-dependent polarization information from light scattered by aerosols. This information will enable accurate prediction of optical properties and light propagation in the MABL. The objective is to develop a new instrument and method to characterize atmospheric aerosols by remotely sensing scattered light. A bi-static nephelometer (an instrument with separately pointed light source and detector that probes at a distance) appears to be an effective tool to supply data regarding aerosol content and light propagation in the MABL. It provides a means to probe the area about its mounting platform whether it is mounted on-shore or shipboard. Light scattering techniques have the advantage of providing a direct, rapid in situ measurement of the optical properties of aerosols. A bi-static nephelometer using polarization modulation can probe at a distance to measure the polarization of light scattered from aerosols in the sensed region. A significant advantage inherent to polarization modulation is that it allows the use of an intensity normalization procedure that permits determination of aerosol size distributions and optical properties using polarization information independent of scattered light intensity. By using various scanning strategies, the aerosols in the MABL about the platform may be characterized for visibility and aerosol content in spatial detail (mapped) with time. To use the bistatic nephelometer measurements effectively an analytical modeling effort that predicts the polarization properties of light scattering from typical atmospheric aerosols is necessary. Therefore scattering models based on Mie calculations must be supplemented with more general calculational approaches that provide for scattering from non-spherical particles. Therefore another objective is to develop viable models to calculate sca
Document Details
- Document Type
- Technical Report
- Publication Date
- Sep 30, 1998
- Accession Number
- ADA541739
Entities
People
- Arlon J. Hunt
- Mary S. Quinby-hunt
Organizations
- University of California, Berkeley