Mesoscale atmospheric dispersion experiments using tracer and tetroons

Abstract

In April 1983, March 1984 and March 1985 four mesoscale atmospheric dispersion experiments were performed near the Kernforschungszentrum Karlsruhe. The experiments comprised: tracking of tetroons by radar up to distances of more than 100 km; release of the tracer SF 6 at a height of 100 m or 140 m, respectively, and downwind sampling at more than 50 locations during up to seven successive periods of 30 min duration each up to source distances of 66 km; meteorological measurements at a 200 m high tower and radiosonde ascents up to a height of at least 2000 m. The measured data have been analyzed to obtain dispersion parametersσ y and σ z as a function of downwind distance and sampling time.σ y derived from tracer concentrations and from tetroon trajectories can be well compared, if the duration of the sampling time is taken into account. Vertical wind speeds and turbulence intensities are determined from tetroon trajectories. The turbulence intensities are compared to stability classes derived from meteorological measurements.