Characterization and intercomparison of aerosol absorption photometers: result of two intercomparison workshops

T. Muller (1) , J. S. Henzing (2) , G. de Leeuw (2, 3, 4) , A. Wiedensohler (1) , A. Alastuey (5) , H. Angelov (6) , M. Bizjak (7) , M. C. Coen (8) , J. E. Engstrom (9) , C. Gruening (10) , R. Hillamo (4) , A. Hoffer (11) , K. Imre (11) , P. Ivanow (6) , G. Jennings (12, 13) , J. Y. Sun (14) , N. Kalivitis (14) , H. Karlsson (15) , M. Komppula (16) , Paolo Laj (17, 18) , S. M. Li (19) , C. Lunder (19) , A. Marinoni (20) , S. M. dos Santos (21) , M. Moerman (2) , A. Nowak (22) , J.A. Ogren (23) , A. Petzold (24) , J. M. Pichon (18) , S. Rodriquez , S. Sharma (23) , P. J. Sheridan (23) , K. Teinilä (22) , T. Tuch (22) , M. Viana (5) , A. Virkkula (3) , E. Weingartner (25) , R. Wilhelm (26) , Y.Q. Wang (27)

1 TROPOS - Leibniz-Institut für Troposphärenforschung
2 TNO - Netherlands Organization for Applied Scientific Research
3 Helsingin yliopisto = Helsingfors universitet = University of Helsinki
4 FMI - Finnish Meteorological Institute
5 IDAEA - Institute of Environmental Assessment and Water Research
6 Institute for Nuclear Research and Nuclear Energy
7 Faculty of Health Sciences
8 Payerne Aerological Station
9 MISU - Department of Meteorology [Stockholm]
10 JRC - European Commission - Joint Research Centre [Ispra]
11 Department of Earth and Environmental Sciences [Veszprém]
12 Environmental Change Institute [Galway]
13 School of Physics [NUI Galway]
14 ECPL - Environmental Chemical Processes Laboratory [Heraklion]
15 Institute for Applied Environmental Research [Stockholm]
16 Kuopio Unit [FMI]
17 LGGE - Laboratoire de glaciologie et géophysique de l'environnement
18 LaMP - Laboratoire de météorologie physique
19 NILU - Norwegian Institute for Air Research
20 ISAC - CNR Institute of Atmospheric Sciences and Climate
21 TNO - The Netherlands Organisation for Applied Scientific Research
22 TROPOS - Leibniz Institute for Tropospheric Research
23 GML - ESRL Global Monitoring Laboratory [Boulder]
24 IPA - DLR Institut für Physik der Atmosphäre
25 LAC - Laboratory of Atmospheric Chemistry [Paul Scherrer Institute]
26 MOHp - Meteorologisches Observatorium Hohenpeißenberg
27 CAMS - Chinese Academy of Meteorological Sciences

Absorption photometers for real time application have been available since the 1980s, but the use of filter-based instruments to derive information on aerosol properties (absorption coefficient and black carbon, BC) is still a matter of debate. Several workshops have been conducted to investigate the performance of individual instruments over the intervening years. Two workshops with large sets of aerosol absorption photometers were conducted in 2005 and 2007. The data from these instruments were corrected using existing methods before further analysis. The inter-comparison shows a large variation between the responses to absorbing aerosol particles for different types of instruments. The unit to unit variability between instruments can be up to 30% for Particle Soot Absorption Photometers (PSAPs) and Aethalometers. Multi Angle Absorption Photometers (MAAPs) showed a variability of less than 5%. Reasons for the high variability were identified to be variations in sample flow and spot size. It was observed that different flow rates influence system performance with respect to response to absorption and instrumental noise. Measurements with non absorbing particles showed that the current corrections of a cross sensitivity to particle scattering are not sufficient. Remaining cross sensitivities were found to be a function of the total particle load on the filter. The large variation between the response to absorbing aerosol particles for different types of instruments indicates that current correction functions for absorption photometers are not adequate.

Keywords: Soot Particles; Black Carbon Content; Aethalometer; Calibration; Attenuation Cross-Section; Filter-Based Measurements; Integrating Nephelometers; Size; Visible-Light Absorption; Ambient Measurements

Domains: Sciences of the Universe [physics]; Earth Sciences; Geomorphology

T. Muller, J. S. Henzing, G. de Leeuw, A. Wiedensohler, A. Alastuey, et al.. Characterization and intercomparison of aerosol absorption photometers: result of two intercomparison workshops. Atmospheric Measurement Techniques, 2011, 4 (2), pp245-268. ⟨10.5194/amt-4-245-2011⟩. ⟨insu-00605084⟩