Atmospheric Chemistry of Titan Options

[Juramike]

Here is a "Benzene-O-Vision" graphic showing the amount of benzene and phenyl radicals at high altitudes on Titan. This is based on detections of benzene and phenyl radical (which recombined in the sample chamber to make benzene) using the INMS instrument during closest approach. The numbers are normalized to constant pressure altitude, roughly 1000 km.



The data was taken from Table 1 in: Vuitton et al, Journal of Geophysical Research 113 (2008) E05007. "Formation and distribution of benzene on Titan". doi: 10.1029/2007JE002997 [EDIT 5/24/10: Article freely available here] and overlaid on a map of Titan.

The authors mentioned that the errors in these measurements are 20%.

These detections are well above the detached haze layer. Most are at the same sun azimuth angle. (T23 observation had the lowest angle.) Assuming that the temporal difference is minimal (each dot is from a different flyby), there doesn't appear to be an obvious correlation with latitude.

This graphic does show that benzene is present even waaaay up in the thermosphere and ionosphere.

[Juramike]

I agree that the reality is probably a lot more complicated than the model, with changing solar flux rates (11-year cycle) and seasonal illumination changes, and material (starting materials and products) fluxes and thus concentration values going up and down and then the molecules themselves physically going up and down and back and forth. All of those should also affect the chemical flux rates.

IIRC the mean free path length at 1000 km altitude is a few km long, so only a few ricochets are in the way of a 100 km molecular journey.

(I seem to also remember that Voyager 1 had a different value for the detached haze layer, much lower if I remember correctly.)

What measurements would be required to constrain chemical flux vs. dynamics?
(...and did we just get these on the last flyby?)