An aerosol measurement campaign was carried out in the summer of 2022 at a NOAA (National Oceanic and Atmospheric Administration) field site north of Boulder, Colorado, USA. Two camera lidars were deployed at 532 and 808 nm. The unique properties of the camera lidar include aerosol profiles all the way to the ground at high resolution where they can be compared with in-situ measurements. Surface aerosol measurements included three-wavelength total scatter and absorption, as well as condensation nuclei and particle size distributions. The camera lidar extinctions at the surface compared well with the in-situ extinctions. The 532/808 Angstrom exponent in the Planetary Boundary Layer was 1.0 and for an upper tropospheric layer it was 2.5 indicating smaller particles.
Barnes et al. (2026) studied this question.