Mountain Breezes at Three Different Sites: Salt Lake Valley, The Pyrenees and Guadarrama Mountain Range.

Near-surface observational data from three different sites have been analyzed during periods of several months with the objective of performing robust statistics for the characterization of mountain breezes. These sites are located in the foothills of the Guadarrama mountains range (El Escorial, Spain), on a plateau close to The Pyrenees (Lannemezan, France) and within the Salt Lake Valley (Utah, US). A systematic algorithm has been used to automatically detect the katabatic and anabatic events at each site, based on the synoptic and local meteorological conditions. After their detection, these breezes have been studied and characterized by the changes observed in different near-surface micrometeorological variables. Special attention has been paid to the breeze effects on the surface turbulence fluxes and on the changes observed in CO₂ and water vapor concentration during the development of these flows. The statistical description has been complemented with the detailed analysis of specific and representative case studies, in order to better illustrate how these systems are influencing the local conditions at the three sites. Although the analysis of differences between the three diverse sites is naturally a difficult task, the study of their similarity facilitates the establishment of more robust conclusions on meso-microscale interactions, as well as the definition of the characteristics and the impacts of these phenomena in the lower part of the planetary boundary layer.