Simultaneous measurements of the relative-humidity-dependent aerosol light extinction, scattering, absorption, and single-scattering albedo with a humidified cavity-enhanced albedometer
Open Access
- 20 May 2020
- journal article
- research article
- Published by Copernicus GmbH in Atmospheric Chemistry and Physics
- Vol. 13 (5), 2623-2634
- https://doi.org/10.5194/amt-13-2623-2020
Abstract
Hygroscopic aerosols take up water and grow with increasing relative humidity (RH), giving rise to large changes in light extinction (b(ext)), scattering (b(scat)), absorption (b(abs)), and single scattering albedo (SSA, omega). The optical hygroscopic growth factors for each parameter (f (RH)(ext,cat,abs,omega)) are thus important for assessing aerosol effects on regional air quality, atmospheric visibility, and radiative forcing. The RH dependence of aerosol scattering and extinction has been studied in many laboratory and field studies. However, owing partly to the absence of suitable instrumentation, there are few reports of the RH dependence of aerosol absorption and omega. In this work, we report the development of a humidified cavity-enhanced albedometer (H-CEA) for simultaneous measurements of f (RH)(ext,sct,abs,omega) at lambda = 532 nm from 10% to 88% RH. The instrument's performance was evaluated with laboratory-generated ammonium sulfate, sodium chloride, and nigrosin aerosols. Measured hygroscopic growth factors for different parameters were in good agreement with model calculations and literature-reported values, demonstrating the accuracy of the H-CEA for measuring RH-dependent optical properties.Funding Information
- National Natural Science Foundation of China (4190050321)
- Natural Science Foundation of Anhui Province (1908085QD157)
This publication has 54 references indexed in Scilit:
- Portable broadband cavity-enhanced spectrometer utilizing Kalman filtering: application to real-time, in situ monitoring of glyoxal and nitrogen dioxideOptics Express, 2017
- Aerosol hygroscopicity parameter derived from the light scattering enhancement factor measurements in the North China PlainAtmospheric Chemistry and Physics, 2014
- Laboratory-Measured Optical Properties of Inorganic and Organic Aerosols at Relative Humidities up to 95%Aerosol Science and Technology, 2012
- Measurement of relative humidity dependent light scattering of aerosolsAtmospheric Chemistry and Physics, 2010
- Sensitivity of aerosol optical thickness and aerosol direct radiative effect to relative humidityAtmospheric Chemistry and Physics, 2009
- Relative humidity dependence of aerosol optical properties and direct radiative forcing in the surface boundary layer at Xinken in Pearl River Delta of China: An observation based numerical studyAtmospheric Environment, 2008
- Measurement of the refractive index of distilled water from the near-infrared region to the ultraviolet regionApplied Optics, 2007
- Integrating nephelometer with a low truncation angle and an extended calibration schemeMeasurement Science and Technology, 2006
- Key factors influencing the relative humidity dependence of aerosol light scatteringGeophysical Research Letters, 2006
- Photoacoustic and filter‐based ambient aerosol light absorption measurements: Instrument comparisons and the role of relative humidityPublished by American Geophysical Union (AGU) ,2003