Plume behavior as controlled by the stable boundary layer

Complex dynamics of the stable planetary boundary layer (PBL), such as the effects of density currents, intermittent turbulence, and internal gravity waves, affect plume transport and diffusion. The JORNADA (Joint Observational Research on Nocturnal Atmospheric Dispersion of Aerosols) field campaign, conducted in the New Mexico desert during April 2005, seeks to utilize continuous lidar measurements of an elevated plume and an array of micrometeorological measurements to characterize some of these effects. Micrometeorological issues addressed in the project are the persistence of SBL conditions including turbulence, the connectivity between the roughness sublayer and the SBL, and wave modifications of turbulence. This paper presents examples of intermittent turbulence, varying wind conditions and the resulting plume spread, meander, fluctuations as well as analysis techniques to address the persistence of mesoscale and turbulent motions.