Accurate Quantification of Single Aerosol Particle Microphysical Properties Using Broadband Light Scattering...

Area of Science:

• Atmospheric science
• Aerosol optics
• Spectroscopy

Background:

• Wavelength-dependent refractive indices of aerosols are critical for atmospheric science.
• Broadband light scattering (BLS) can measure these properties at the single-particle level.
• Current BLS spectral analysis is time-consuming due to extensive spectral simulations.

Purpose of the Study:

• To develop a faster method for fitting BLS spectra of single aerosol particles.
• To reduce the computational time required for BLS data analysis.
• To accurately determine aerosol particle size and refractive indices using BLS.

Main Methods:

• Introduced a novel approach to fitting BLS spectra by minimizing spectral calculations.
• Validated the method by comparing BLS measurements with cavity ring-down spectroscopy (CRDS) for benchmark aerosol species.
• Used retrieved parameters in simulations to reproduce experimental BLS and CRDS data.

Main Results:

• The new BLS fitting method significantly reduces analysis time.
• Accurate retrieval of aerosol particle radii (0.8-2.5 μm) with ~1.4 nm precision.
• Precise determination of the real component of the complex refractive index (∼10⁻³ precision) across 380-800 nm.

Conclusions:

• The developed BLS spectral fitting approach is efficient and accurate.
• This method enhances the utility of BLS for single aerosol particle characterization.
• The findings improve our ability to study aerosol optical properties in the atmosphere.