Darci Snowden (Physics)
Titan, the largest of Saturn’s moons, was the target of a series of flybys from NASA’s Cassini mission. We will use the data from the 5th flyby of Cassini (T5), where the Ion and Neutral Mass Spectrometer (INMS) measured ionic and neutral particle densities within the atmosphere. The data recorded displayed a sharp decrease in densities of ions with short lifetimes, like CH5+, whereas ions with longer lifetimes did not have this same decrease. One possible explanation of this decrease is that there could be an atmospheric wave propagating, changing ion densities. If we can model this decrease, then we can not only explain the data but also have a new way of understanding the waves in Titan’s atmosphere, which will lead towards a deeper understanding of the structure and transport of energy of Titan. To explore the ionosphere of Titan, I created a model that uses photoionization to simulate the chemistry where the densities of each ion species is determined by solving the continuity equation with production and loss terms from the reaction equations. When this photochemical model is complete, a vertically propagating wave will be added to explain the sharp decrease of the ion densities. Once the vertical wave is added to the system, we can explore the effect of different wave parameters to see if the T5 data can be reproduced with this model. Should the model work as hoped, we can then look at the other flybys and analyze that data as well.
Keywords: Titan, ionosphere, photochemistry