Fig. 2: Time series of 1-Hz data measured in the A320 contrail when burning low-aromatic semisynthetic jet fuel SSF1.
From: Cleaner burning aviation fuels can reduce contrail cloudiness

Number concentrations of ice crystals with diameters larger than 0.5 μm (nice), nonvolatile (i.e., soot) particles in the size range of 0.01–1.9 μm (nsoot), altitude of Falcon (solid black line) and A320 (dashed black line), ambient temperature (gray line) and CO2 mixing ratio. Measurements were taken at contrail ages from 48 to 134 s and distances between 7 and 41 km.