Calibration and intercomparison of filter-based measurements of visible light absorption by aerosols

Citation
Tc. Bond et al., Calibration and intercomparison of filter-based measurements of visible light absorption by aerosols, AEROS SCI T, 30(6), 1999, pp. 582-600
Citations number
38
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Mechanical Engineering
Journal title
AEROSOL SCIENCE AND TECHNOLOGY
ISSN journal
0278-6826 → ACNP
Volume
30
Issue
6
Year of publication
1999
Pages
582 - 600
Database
ISI
SICI code
0278-6826(199906)30:6<582:CAIOFM>2.0.ZU;2-J
Abstract
Data on light absorption by atmospheric particles are scarce relative to th e need for global characterization. Most of the existing data come from met hods that measure the change in light transmission through a filter on whic h particles are collected. We present a calibration of a recently developed filter-based instrument for continuous measurement of light absorption (mo del PSAP, Radiance Research, Seattle, WA) that has been incorporated in sev eral measurement programs. This calibration uses a reference absorption det ermined as the difference between light extinction and light scattering by unaltered (suspended) particles. In addition, we perform the same calibrati on for two other common filter-based methods: an Integrating Plate and the Hybrid Integrating Plate System, For each method, we assess the responses t o both particulate light scattering and particulate light absorption. We fi nd that each of the instruments exhibits a significant response to nonabsor bing aerosols and overestimates absorption at 550 nm by suspended particles by about 20-30 %. We also present correction factors for the use of the PS AP.