The photos hyperlinked from this page show particles emitted from jet aircraft engines under flight conditions. These particulate samples were collected using a low-pressure impactor onboard a NASA chase aircraft during the SASS/SNIF III field experiment. All photomicrographs were taken with a JEOL Model 200CX analytical transmission electron microscope operating at 200 kV potential.

1. F-16 exhaust particles, JP-8 fuel, 0.05 nautical mile separation between aircraft and chase plane, 10.7 km altitude. No sulfuric acid droplets are visible and no S signal is observed in the soot particles. View photo 1.

2. F-16 exhaust particles, JP-8 fuel, 0.05 nautical mile separation between aircraft and chase plane, 10.7 km altitude. No sulfuric acid droplets are visible and no S signal is observed in the soot particles. View photo 2.

3. F-16 exhaust particles, high-S fuel, 0.1 nautical mile separation between aircraft and chase plane, 10.8 km altitude. Sulfuric acid droplets are visible in this sample and S is found in/on some of the soot particles. View photo 3.

4. F-16 exhaust particles, high-S fuel, 0.1 nautical mile separation between aircraft and chase plane, 10.8 km altitude. Sulfuric acid droplets are visible in this sample and S is found in/on some of the soot particles. View photo 4.

5. As chase plane increases distance between itself and emitter aircraft, relative ratio of sulfuric acid to soot particles increases. View photo 5.

6. As chase plane increases distance between itself and emitter aircraft to a point where it is no longer directly in the exhaust plume but rather flying in air that contains older but relatively recent emissions, an even larger fraction of sulfuric acid particles are observed.  The faint sub-0.1 mm particles are sulfuric acid droplets as typically viewed in our electron microscope. View photo 6.

7. Very small soot particles on the surface of a sulfuric acid droplet.  View photo 7.