PARTICLE COMPOSITION OF A YOUNG CONDENSATION TRAIL AND OF UPPER-TROPOSPHERIC AEROSOL

Aerosol and contrail particles in a young exhaust plume of an Airbus A 310-300 were characterized with respect to size distribution and refra ctive index at plume ages less than or equal to 2 sec. The instrumenta tion included standard particle spectrometers (PCASP-100X, FSSP-300) a nd a new instrument (Multiangle Aerosol Spectrometer Probe, MASP) for simultaneous measurement of particle size and refractive index. The pa rticle size distributions as measured with the standard FSSP-300 and t he new MASP showed good agreement. The observed refractive indices ind icated a mixture of pure ice particles, black carbon aerosol, and an i nternal mixture of these components in the contrail, while black carbo n and sulfate-containing compounds dominated the upper tropospheric ba ckground aerosol.