Aerosol Properties & Processes: Instruments

Aerosol Optical Properties (AOP)

The Aerosol Optical Properties (AOP) suite of instruments consists of a cavity ringdown spectrometer (CRD) and a photoacoustic spectrometer (PAS) that measure aerosol extinction and absorption at multiple wavelengths across the visible spectrum. In addition to bulk extinction and absorption the AOP suite includes channels both up and downstream of thermodenuders and humidification to determine aerosol volatility and hygroscopicity. An optical particle counter (UHSAS) is also typically included in the AOP suite.

Field Projects / Platforms

• California Research at the Nexus of Air Quality and Climate Change (CalNex) 2010 (NOAA WP-3D)
• Deep Convective Clouds & Chemistry (DC3) Experiment 2012 (NASA DC-8)
• Studies of Emissions and Atmospheric Composition, Clouds and Climate Coupling by Regional Surveys (SEAC⁴RS) 2013 (NASA DC-8)
• Fire Influence on Regional to Global Environments and Air Quality (FIREX-AQ) 2019 (NASA DC-8)

Key Publications

Lack, D.A., M.S. Richardson, D. Law, J.M. Langridge, C.D. Cappa, R.J. McLaughlin, and D.M. Murphy, Aircraft instrument for comprehensive characterization of aerosol optical properties, Part 2: Black and brown carbon absorption and absorption enhancement measured with photo acoustic spectroscopy, Aerosol Science and Technology, doi:10.1080/02786826.2011.645955, 2012.

Langridge, J.M., M.S. Richardson, D. Lack, D. Law, and D.M. Murphy, Aircraft instrument for comprehensive characterization of aerosol optical properties, Part I: Wavelength-dependent optical extinction and its relative humidity dependence measured using cavity ringdown spectroscopy, Aerosol Science and Technology, doi:10.1080/02786826.2011.592745, 2011.