Comparison of two Lagrangian dispersion models: A case study for the chemical accident in Rouen, January 21-22, 2013

Ádám Leelossy, Erika Lilla Ludányi, Márk Kohlmann, István Lagzi, Róbert Mészáros

Research output: Contribution to journalArticle

3 Citations (Scopus)


Industrial accidents have been a serious environmental and public health issue for the last decades. Although the development of atmospheric dispersion models was largely motivated by the notorious nuclear catastrophes, simulations are now mostly used in cases of chemical accidents that regularly occur in all parts of the world. In an accidental situation, the accuracy of the results is primarily important for risk management and decision making strategies. However, it largely depends on the meteorological conditions and the quality of input data. A chemical accident happened in a factory in Rouen, France on January 21, 2013. The emitted methyl mercaptan gas caused odor and sickness in densely populated areas, including Paris. The meteorological conditions were rapidly changing in both space and time during the release period, thus the case is particularly challenging for dispersion models and provides a good basis for testing them. Dispersion of the released methyl mercaptan gas was estimated using the PyTREX trajectory model, developed at the Eötvös Loránd University, and NOAA's HYSPLIT model. The simulation results are in a good agreement with media reports of the polluted areas, and lead to a better understanding of the complex synoptic situation at the time of the accident. Comparison of the results of two models also provided information about the uncertainty of the predictions and pointed out the most important directions for further development of the PyTREX model.

Original languageEnglish
Pages (from-to)435-450
Number of pages16
Issue number4
Publication statusPublished - Oct 1 2013



  • Accidental release
  • Air pollution
  • Atmospheric dispersion
  • Industrial accident
  • Lagrangian model

ASJC Scopus subject areas

  • Atmospheric Science

Cite this

Leelossy, Á., Ludányi, E. L., Kohlmann, M., Lagzi, I., & Mészáros, R. (2013). Comparison of two Lagrangian dispersion models: A case study for the chemical accident in Rouen, January 21-22, 2013. Idojaras, 117(4), 435-450.