Validation of LEEDR-calculated aerosol extinction using micro- and nano-particle concentration inputs at North American locations

Aerosols can impact atmospheric laser propagation by absorbing and scattering light. Traditional measurements of aerosol extinction, such as filter-based photometers and nephelometers, are often limited to the visible spectrum, which makes them less than ideal for near-infrared applications. Direct measurement methods, like cavity-based ringdown techniques or calculations using the radiative transfer code LEEDR (laser environmental effects definition and reference), can overcome this limitation. This study compares LEEDR outputs, incorporating nano- and micro-particle concentrations, with measured aerosol extinction at multiple North American sites. Results show that with measurements of pressure, temperature, humidity, and particle counts, LEEDR accurately quantifies aerosol extinction, making it a valuable tool for quantifying aerosol effects on atmospheric laser propagation.