FluxSAP 2010 experimental campaign over an heterogeneous urban zone, part 2: quantification of plume vertical dispersion during a gas tracer experiment using a mast and a small tethered balloon

FluxSAP 2010 is the first of two experimental campaigns aiming at quantitatively assessing the contribution of urban vegetation in the sensible heat and water vapour fluxes, over a heterogeneous area including buildings, semi-impervious surfaces, low and high vegetation. In this framework, we have performed a gas tracer experiment to quantify the vertical expansion of a plume, using a mast and a small tethered balloon as carriers for the tracer samplers. The first goal of this experiment is a better understanding and quantification of plume vertical dispersion in an urban area as a function of the atmospheric turbulence. The second objective is to assess atmospheric dispersion models and footprint models in urban areas.