pass > Photoacoustic Soot SpectrometerInstrument Type(s) > Baseline • Guest

The photoacoustic soot spectrometer (PASS) measures light absorption by aerosol particles. As the particles pass through a laser beam, the absorbed energy heats the particles and in turn the surrounding air, which sets off a pressure wave that can be detected by a microphone.

The PASS instruments can also simultaneously measure the scattered laser-light at three wavelengths and therefore provide a direct measure of the single-scattering albedo.

The PASS is part of the aerosol observing system (AOS).



  • Fixed
  • AMF1
  • AMF2
  • AMF3


Li H, G McMeeking, and A May. 2020. "Development of a new correction algorithm applicable to any filter-based absorption photometer." Atmospheric Measurement Techniques, 13(5), 10.5194/amt-13-2865-2020.

Junghenn Noyes K, R Kahn, A Sedlacek, L Kleinman, J Limbacher, and Z Li. 2020. "Wildfire Smoke Particle Properties and Evolution, from Space-Based Multi-Angle Imaging." Remote Sensing, 12(5), 10.3390/rs12050769.


Forestieri S, T Helgestad, A Lambe, L Renbaum-Wolff, D Lack, P Massoli, E Cross, M Dubey, C Mazzoleni, J Olfert, A Sedlacek III, A Freedman, P Davidovits, T Onasch, and C Cappa. 2018. "Measurement and modeling of the multiwavelength optical properties of uncoated flame-generated soot." Atmospheric Chemistry and Physics, 18(16), 10.5194/acp-18-12141-2018.

Sheesley RJ, R Subramanian, C Flynn, M Dubey, N Hickmon, and S Yoon. 2018. Absorption at San Antonio with 3-Wavelength Photoacoustic Soot Spectrometer, Tricolor Absorption Photometer (ASAPT) Field Campaign Report. Ed. by Robert Stafford, ARM Climate Research Facility. DOE/SC-ARM-18-003.


Dubey M, A Aiken, LK Berg, A Freedman, and K Gorkowski. 2016. Two-Column Aerosol Project: Aerosol Light Extinction Measurements Field Campaign Report. Ed. by Robert Stafford, DOE ARM Climate Research Facility. DOE/SC-ARM-16-047.

Worsnop DR, LR Williams, SC Herndon, M Dubey, NL Ng, J Thornton, B Knighton, R Coulter, and A Prevot. 2016. Clean Air for London (CLEARFLO) Final Campaign Summary. Ed. by Robert Stafford, DOE ARM Climate Research Facility. DOE/SC-ARM-15-015.

Kleinman LI, AJ Sedlacek, WP Arnott, PR Buseck, P Davidovits, JS Gaffney, ER Lewis, W Lin, H Moosmuller, TB Onasch, JE Shilling, J Wang, RJ Yokelson, and RA Zaveri. 2016. Biomass Burning Observation Project (BBOP) Final Campaign Report. Ed. by Robert Stafford, DOE ARM Climate Research Facility. DOE/SC-ARM-15-083.


Jefferson A. 2014. Continuous Light Absorption Photometer (CLAP) Final Campaign Report. U.S. DOE, Office of Science, Office of Biological and Environmental Research. DOE/SC-ARM-14-013.

Schmid B, JM Tomlinson, JM Hubbe, JM Comstock, F Mei, D Chand, MS Pekour, CD Kluzek, E Andrews, SC Biraud, and GM McFarquhar. 2014. "The DOE ARM Aerial Facility." Bulletin of the American Meteorological Society, 95(5), 10.1175/bams-d-13-00040.1.


Hiranuma N, SD Brooks, RC Moffet, A Glen, A Laskin, MK Gilles, P Liu, AM Macdonald, JW Strapp, and GM McFarquhar. 2013. "Chemical characterization of individual particles and residuals of cloud droplets and ice crystals collected on board research aircraft in the ISDAC 2008 study." Journal of Geophysical Research: Atmospheres, 118(12), 10.1002/jgrd.50484.
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