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RESEARCH PRODUCT

Analyse de la répartition spatiale des concentrations d'ozone en Bourgogne

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National audience; ABSTRACT : A series of measurements by passive tubes with diffusion were carried out in August 2000 on all the Burgundy area in order to try to better understand the spatial patterns of ozone at regional scale. As expected, the results showed difference between night and day. In addition ozone variability is associated to spatial and temporal scales. We assumed that ozone concentrations is the additive combination of two main sources: a "low frequency" signal due to external forcing and a high frequency signal from local origin. Spatial correlations were characterised by the experimental and the modelled semivariogram. Spatial correlations are strongly anisotropic. The analysis and a preliminary interpretation of this structure were finally led using a GIS. Results show first the dispersive effects to the wind speed. Moreover, for certain dates the spatial structure is mainly driven by the combination of surface roughness characteristics (local wind direction), the level of ozone concentration added by the wind. Finally, we discuss the context of such results for ozone mapping purpose.