1. Generally contrail ice in near equilibrium with ice mass proportional to contrail volume (except for the rapidly falling vortices early, and precipitation regions later).

2. Contrail volume largely determined by vortex dynamics (until ~ 4 min.) and Brunt-Vaisala oscillations (until ~ 20 min.).

3. Passive tracer, ice mass and ice number density distributions differ (strong dependence on RH _ice ).

4. Heating due to adiabatic compression of falling vortex system can lead to significant ice crystal number depletion. (depending on RH _ice , EI _ice# , aircraft type).

5. Strong species fluctuations can have a significant impact on measured chemistry [e.g. HO₂ /OH] in the aircraft wake.