uhsas > Ultra-High Sensitivity Aerosol SpectrometerInstrument Type(s) > Baseline • Guest

The ultra-high-sensitivity aerosol spectrometer (UHSAS) is an optical-scattering, laser-based, aerosol particle spectrometer system for sizing particles in the 60 to 1000 nanometer (nm) range [1–3].

The instrument counts particles in up to 100 user-specified sizing bins. The instrument’s laser illuminates particles, which scatter light. The system captures the peak light signals that are generated. These signals are used for particle sizing, since the amount of light scattered correlates strongly with particle size.

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



  • Fixed
  • AMF1
  • AMF2
  • AMF3

Active Locations

Facility Name Start Date
Gunnison, CO; Supplemental Facility 2 2021-09-01
Houston, TX; AMF1 (main site for TRACER) 2021-04-14


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Research Highlight

Geerts B, G McFarquhar, L Xue, M Jensen, P Kollias, M Ovchinnikov, M Shupe, P DeMott, Y Wang, M Tjernstrom, P Field, S Abel, T Spengler, R Neggers, S Crewell, M Wendisch, and C Lupkes. 2021. Cold-Air Outbreaks in the Marine Boundary Layer Experiment (COMBLE) Field Campaign Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-21-001.


Li H and A May. 2020. "An Exploratory Approach Using Regression and Machine Learning in the Analysis of Mass Absorption Cross Section of Black Carbon Aerosols: Model Development and Evaluation." Atmosphere, 11(11), 10.3390/atmos11111185.

Shinozuka Y, P Saide, G Ferrada, S Burton, R Ferrare, S Doherty, H Gordon, K Longo, M Mallet, Y Feng, Q Wang, Y Cheng, A Dobracki, S Freitag, S Howell, S LeBlanc, C Flynn, M Segal-Rosenhaimer, K Pistone, J Podolske, E Stith, J Bennett, G Carmichael, A da Silva, R Govindaraju, R Leung, Y Zhang, L Pfister, J Ryoo, J Redemann, R Wood, and P Zuidema. 2020. "Modeling the smoky troposphere of the southeast Atlantic: a comparison to ORACLES airborne observations from September of 2016." Atmospheric Chemistry and Physics, 20(19), 10.5194/acp-20-11491-2020.

Emerson E, A Hodshire, H DeBolt, K Bilsback, J Pierce, G McMeeking, and D Farmer. 2020. "Revisiting particle dry deposition and its role in radiative effect estimates." Proceedings of the National Academy of Sciences, , 202014761, 10.1073/pnas.2014761117.
Research Highlight

Watson T, A Aiken, Q Zhang, P Croteau, T Onasch, L Williams, and C Flynn. 2020. Second ARM Aerosol Chemical Speciation Monitor Users’ Meeting Report. Ed. by Robert Stafford, ARM user facility. DOE/SC-ARM-TR-249.

Zheng G, A Sedlacek, A Aiken, Y Feng, T Watson, S Raveh-Rubin, J Uin, E Lewis, and J Wang. 2020. "Long-range transported North American wildfire aerosols observed in marine boundary layer of eastern North Atlantic." Environment International, 139, 10.1016/j.envint.2020.105680.

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