Figure 322
Fig. 322
normal (630x427, 16 KB) large (1024x693, 31 KB) EPS (8 KB)
Schematic of the various aerosol types present in young jet aircraft exhaust plumes (adapted from Kärcher, 1998a). Shown are approximate size distributions (solid line) versus radius for volatile particles (neutral and chemi-ion modes) and soot (primary and secondary modes), when no contrail is produced by the aircraft. If a contrail is formed, these size distributions change (not shown), and ice particles are created (dashed line). Size distributions of soot and ice particles have been measured in situ. Mean sizes and numbers of ion mode particles have been deduced from particle counter measurements and corresponding size distributions of volatile particles have been inferred from simulation models. The bars indicate the approximate range of variability due to variations of fuel sulfur content, engine emission parameters, and ambient conditions, as suggested by an evaluation of current observations and modeling studies. An approximate background aerosol size distribution is included for comparison (dot-dashed line) (see Table 3.2.1).