atmosphere Article Wintertime Local Wind Dynamics from Scanning Doppler Lidar and Air Quality in the Arve River Valley Tiphaine Sabatier *, Alexandre Paci ID , Guylaine Canut, Yann Largeron, Alain Dabas ID , Jean-Marie Donier and Thierry Douffet Centre National de Recherches Météorologiques, METEO-FRANCE & CNRS, UMR 3589, 31100 Toulouse, France;
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[email protected]; Tel.: +33-561-079-896 Received: 25 January 2018; Accepted: 16 March 2018; Published: 21 March 2018 Abstract: Air quality issues are frequent in urbanized valleys, particularly in wintertime when a temperature inversion forms and the air within the valley is stably stratified over several days. In addition to pollutant sources, local winds can have a significant impact on the spatial distribution and temporal evolution of pollutant concentrations. They can be very complex and difficult to represent in numerical weather prediction models, particularly under stable conditions. Better knowledge of these local winds from observations is also a prerequisite to improving air quality prediction capability. This paper analyses local winds during the Passy-2015 field experiment that took place in a section of the Arve river valley, near Chamonix–Mont-Blanc. This location is one of the worst places in France regarding air quality. The wind analysis, which is mainly based on scanning Doppler lidar data sampling a persistent temperature inversion episode, reveals features consistent with the higher pollutant concentrations observed in this section of the valley as well as their spatial heterogeneities.