Particle composition of a young condensation trail and of upper tropospheric aerosol

Aerosol and contrail particles in a young exhaust plume of an Airbus A310‐300 were characterized with respect to size distribution and refractive index at plume ages ≤ 2 sec. The instrumentation included standard particle spectrometers (PCASP‐100X, FSSP‐300) and a new instrument (Multiangle Aerosol Spectrometer Probe, MASP) for simultaneous measurement of particle size and refractive index. The particle size distributions as measured with the standard FSSP‐300 and the new MASP showed good agreement. The observed refractive indices indicated a mixture of pure ice particles, black carbon aerosol, and an internal mixture of these components in the contrail, while black carbon and sulfate‐containing compounds dominated the upper tropospheric background aerosol.