A series of both flight tests and ground experiments has been performed to evaluate the role of the sulfur contained in kerosene in condensation trail (contrail) formation processes. The results of the first experiments are compiled briefly. The last SULFUR 4 experiment dealing with the influence of the fuel sulfur content and different appertaining conditions is described in detail. Different sulfur mass fractions lead to different particle size spectra. The number of ice particles in the contrail increases by about a factor of 2 for 3000 ppm instead of 6 ppm sulfur fuel content. (author) 10 refs.
Busen, R; Kuhn, M; Petzold, A; Schroeder, F; Schumann, U;  Baumgardner, D;  Borrmann, S;  Hagen, D; Whitefield, Ph;  Stroem, J 
- Deutsche Forschungs- und Versuchsanstalt fuer Luft- und Raumfahrt e.V., Oberpfaffenhofen (Germany)
- National Center for Atmospheric Research, Boulder, CO (United States)
- Mainz Univ. (Germany)
- Missouri Univ., Rolla, MO (United States). Bureau of Mines
- Stockholm Univ. (Sweden)