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Evaluation of WRF-Chem Model Forecasts of a Prolonged Saharan Dust Episode over the Eastern Alps

Category: Special Session: Atmospheric Chemistry and Physics at Mountain Sites 2017

Volume: 19 | Issue: 6 | Pages: 1226-1240
DOI: 10.4209/aaqr.2018.03.0116

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To cite this article:
Baumann-Stanzer, K., Greilinger, M., Kasper-Giebl, A., Flandorfer, C., Hieden, A., Lotteraner, C., Ortner, M., Vergeiner, J., Schauer, G. and Piringer, M. (2019). Evaluation of WRF-Chem Model Forecasts of a Prolonged Saharan Dust Episode over the Eastern Alps. Aerosol Air Qual. Res. 19: 1226-1240. doi: 10.4209/aaqr.2018.03.0116.

Kathrin Baumann-Stanzer 1, Marion Greilinger1, Anne Kasper-Giebl2, Claudia Flandorfer1, Alexander Hieden1, Christoph Lotteraner1, Martin Ortner3, Johannes Vergeiner4, Gerhard Schauer5, Martin Piringer1

  • 1 Central Institute for Meteorology and Geodynamics (ZAMG), 1190 Vienna, Austria
  • 2 Institute of Chemical Technologies and Analytics, Vienna University of Technology, 1060 Vienna, Austria
  • 3 ZAMG Customer Service Carinthia, 9020 Klagenfurt, Austria
  • 4 ZAMG Customer Service Tyrol and Vorarlberg, 6020 Innsbruck, Austria
  • 5 ZAMG Customer Service Salzburg and Upper Austria, 5020 Salzburg, Austria


Daily mean PM concentrations highest at mountain tops with south-westerly flow.
Sahara dust cloud leading to maximum PM values at Eastern Alps in early April 2016.
Ceilometer observe descending dust cloud from above into atmospheric boundary layer.
WRF-Chem successfully forecasts on-set, maximum concentrations and end of event.
FLEXPART backwards used to estimate proportion of air from Sahara sub-regions.


Transported Saharan dust creates a substantial natural background to particulate matter concentrations in Central Europe. The contributions by Saharan dust are especially detectable at Alpine mountain sites, where many other sources have little impact. The ability of a chemical weather forecasting model to simulate dust transport is of vital interest, as serious health effects due to this phenomenon, similar in scale to those resulting from nuclear or industrial accidents, wildfires, pollen, etc., may require countermeasures. Thus, we investigate whether the WRF-Chem model set-up, which is run operationally for air quality forecasts in Austria, can accurately predict the transport of the Saharan dust cloud towards Central Europe in April 2016. WRF-Chem simulations with and without desert dust emissions reveal that whenever PM concentrations were high during the three periods of this event, 60–70% of the dust arriving at the Eastern Alps originated in the desert. The measurements and model results deliver a detailed picture of the course of this extraordinary dust event, with successive peaks over the Eastern Alpine region. Using this long-lasting Saharan dust event as an example, a structured step-wise approach is proposed to investigate peak dust episodes based on data analysis of representative background sites, source area analysis by means of Lagrangian dispersion modelling, and coupled meteorological and chemical modelling.


Saharan dust Long-range transport WRF-Chem model FLEXPART model Source-receptor sensitivity Ceilometer

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