A dispersion modelling system SILAM and its evaluation against ETEX data

M. Sofiev (Corresponding Author), P. Siljamo, I. Valkama, Mikko Ilvonen, J. Kukkonen

Research output: Contribution to journalArticleScientificpeer-review

117 Citations (Scopus)

Abstract

This paper presents the SILAM dispersion modelling system that has been developed for solving various forward and inverse dispersion problems. The current operational version is based on a Lagrangian dispersion model that applies an iterative advection algorithm and a Monte Carlo random-walk diffusion representation. The system can utilize meteorological data from either the HIRLAM or ECMWF numerical weather prediction models. We present an evaluation of SILAM against the data of the European Tracer Experiment (ETEX). The model showed an overall time correlation coefficient of 0.6 (over 150 stations), with specific values for the two ETEX measurement arcs of 0.75 and 0.74, respectively. The number of well-reproduced observation sites are 55, 37, and 40—for a Figure of Merit in Time of >0.2, a correlation coefficient of >0.7, and mean observed and modelled values being within a factor of 2, respectively. We have also investigated the sensitivity of the model to the meteorological input data and model setup. The most important factors with regard to the model performance were (i) the selection of the meteorological input data set and (ii) the method used for the atmospheric boundary layer height estimation. The study allowed selection of the optimum setup for the operational model configuration. We also tried to find explanations for the successes and failures of the specific methodologies in order to facilitate broader conclusions on their applicability in emergency dispersion modelling.
Original languageEnglish
Pages (from-to)674-685
Number of pages12
JournalAtmospheric Environment
Volume40
Issue number4
DOIs
Publication statusPublished - 2006
MoE publication typeA1 Journal article-refereed

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tracer
modeling
experiment
evaluation
advection
boundary layer
weather
methodology
prediction

Keywords

  • dispersion modelling
  • model validation
  • emergency preparedness

Cite this

Sofiev, M. ; Siljamo, P. ; Valkama, I. ; Ilvonen, Mikko ; Kukkonen, J. / A dispersion modelling system SILAM and its evaluation against ETEX data. In: Atmospheric Environment. 2006 ; Vol. 40, No. 4. pp. 674-685.
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A dispersion modelling system SILAM and its evaluation against ETEX data. / Sofiev, M. (Corresponding Author); Siljamo, P.; Valkama, I.; Ilvonen, Mikko; Kukkonen, J.

In: Atmospheric Environment, Vol. 40, No. 4, 2006, p. 674-685.

Research output: Contribution to journalArticleScientificpeer-review

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