On the use of manned hydrogen-gas ballooning in boundary layer studies

Measurements of nitrogen dioxide, ozone and, for the first time, on-line, n onmethane hydrocarbons with a quasicontinuous gaschromatographic/flame ioni zation technique were performed on a manned hydrogen-gas balloon platform. A cycle time of 10 min allowed the determination of nonmethane hydrocarbons in the carbon number range of C-4-C-10 with a detection limit of 10 pptv. In addition, meteorological parameters (atmospheric pressure, temperature, humidity) along with GPS-data (global positioning system) was accomplished during the balloon flights. Balloon measurements of trace compounds provide valuable information about photochemical processes in the boundary layer s ince gas ballooning offers the only technique that slays in the same air pa rcel along Langrangian trajectories. In addition, gas ballooning represents a unique tool to elucidate micrometeorological observations such as atmosp heric stability oscillations and local wind fields.