Articles | Volume 3, issue 2
Atmos. Meas. Tech., 3, 457–474, 2010
Atmos. Meas. Tech., 3, 457–474, 2010

  13 Apr 2010

13 Apr 2010

Minimizing light absorption measurement artifacts of the Aethalometer: evaluation of five correction algorithms

M. Collaud Coen1, E. Weingartner2, A. Apituley3, D. Ceburnis4, R. Fierz-Schmidhauser2, H. Flentje5, J. S. Henzing6, S. G. Jennings4, M. Moerman3, A. Petzold7, O. Schmid9,8,*, and U. Baltensperger2 M. Collaud Coen et al.
  • 1MeteoSwiss, Aerological Station, Les Invuardes, 1530 Payerne, Switzerland
  • 2Laboratory of Atmospheric Chemistry, Paul Scherrer Institut, 5232 Villigen PSI, Switzerland
  • 3National Institute for Public Health and the Environment, Bilthoven, The Netherlands
  • 4School of Physics / Environmental Change Institute, National University of Ireland, Galway; Ireland
  • 5Deutscher Wetterdienst (DWD), Meteorologisches Observatorium (MOHP), Albin-Schwaiger-Weg 10, 82383 Hohenpeissenberg, Germany
  • 6Netherlands Organisation for Applied Scientific Research, TNO, 80015 Utrecht, The Netherlands
  • 7Institut für Physik der Atmosphäre, Deutsches Zentrum für Luft- und Raumfahrt, 82234 Wessling, Germany
  • 8Helmholtz Zentrum München, German Research Center for Environmental Health, Institute of Lung Biology and Disease, 85758 Neuherberg/Munich, Germany
  • 9Missouri University of Science and Technology, Center of Excellence for Aerospace Particulate Emissions Reduction Research, Rolla, MO 65409, USA
  • *formerly at: Max Planck Institute for Chemistry, Biogeochemistry Department, 55020 Mainz, Germany

Abstract. The aerosol light absorption coefficient is an essential parameter involved in atmospheric radiation budget calculations. The Aethalometer (AE) has the great advantage of measuring the aerosol light absorption coefficient at several wavelengths, but the derived absorption coefficients are systematically too high when compared to reference methods. Up to now, four different correction algorithms of the AE absorption coefficients have been proposed by several authors. A new correction scheme based on these previously published methods has been developed, which accounts for the optical properties of the aerosol particles embedded in the filter. All the corrections have been tested on six datasets representing different aerosol types and loadings and include multi-wavelength AE and white-light AE. All the corrections have also been evaluated through comparison with a Multi-Angle Absorption Photometer (MAAP) for four datasets lasting between 6 months and five years. The modification of the wavelength dependence by the different corrections is analyzed in detail. The performances and the limits of all AE corrections are determined and recommendations are given.