Publications

In the context of this thesis airborne measurements of the atmospheric aerosol had been performed. The measuring instrument used therefore (FSSP-300) measures the intensity of the light scattered by individual aerosol particles in forward direction. The size range covers particles with diameters of approximately 0,4 µm to 20 µm. The FSSP-300 was used on several research airplanes, among others for the first time the Russian high-altitude research aircraft Geophysika.

During the field campaign ACE-2 in July 1997 from Tenerife island two layers of wind-carried Saharan dust were encountered. A lower layer was observed up to altitudes of 1500 m while the upper layer reached 6000 m, with a thickness of more than 3000 m. In an analysis of the weather conditions and of backwards trajectories the origin of the dust could be traced. The size distributions measured with the FSSP-300 are juxtaposed to measurements of other particle measuring instruments and compared with data from the literature.

In the context of the investigation on stratospheric aerosol, measurements from two periods without volcanic influence and from the time after the eruption of the Mount Pinatubo were compared. The two periods of background aerosol had been more than five years after the last large volcano eruptions and are thus comparable. The analysis of the aerosol measurements covers the temporal evolution of the total concentration and the comparison of size distributions from these different periods.

Finally upper tropospheric and lower stratospheric measurements in the Indian ocean region during the APE-THESEO field campaign on the Seychelles island Mah´e are presented. On two flights different layers of cirrus clouds had been observed: one within an outflow of a Cumulonimbus and another directly beneath the tropopause. The second and also some regions of the first were subvisible, i.e. had an optical thickness of less than 0.03 at visible light wavelength. The cloud- and aerosol-particle-measurements are shown together with the results of other measuring instruments. Furthermore a meteorological analysis of the weather situation is conducted. The measured size distributions are an important completion of the sparse previous publications on this topic.

Publications

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