Nephelometer Implementation in Microphysical Retrievals of Aerosol Properties

The complex mixture of aerosols and particulate matter in the atmosphere is of significant importance to climatology and public health. In comparison to remote lidar sensing methods, which encounter inconsistencies in accurately detecting the low-level atmospheric aerosol distributions, microphysical retrievals reveal a more detailed picture of surface-range aerosols and their effect on air quality. A polarized imaging nephelometer is an in-situ instrument that is used to conduct these retrievals. It directs a high-speed laser beam, operated at the wavelengths of 445, 532, or 661 nm, at an air sample to measure physical and optical properties of the aerosol. These properties include sphericity, variations of particle sizes, and the refractive index, all of which can be affected by humidity in the environment.

Over the fall and winter of 2018, air samples from the Baltimore, MD area will be collected and assessed for aerosol properties using the nephelometer. Measurements will also be taken in conjunction with varying degrees of applied humidity, in an attempt to understand how daily weather and environmental conditions impact the composition of aerosols at the Earth's surface.