1
|
Mandt K, Luspay-Kuti A, Hamel M, Jessup KL, Hue V, Kammer J, Filwett R. Photochemistry on Pluto: part II HCN and nitrogen isotope fractionation. Mon Not R Astron Soc 2017; 472:118-128. [PMID: 31105342 PMCID: PMC6525008 DOI: 10.1093/mnras/stx1587] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/09/2023]
Abstract
We have converted our Titan one-dimensional photochemical model to simulate the photo- chemistry of Pluto's atmosphere and include condensation and aerosol trapping in the model. We find that condensation and aerosol trapping are important processes in producing the HCN altitude profile observed by the Atacama Large Millimeter Array (ALMA). The nitrogen iso- tope chemistry in Pluto's atmosphere does not appear to significantly fractionate the isotope ratio between N2 and HCN as occurs at Titan. However, our simulations only cover a brief period of time in a Pluto year, and thus only a brief portion of the solar forcing conditions that Pluto's atmosphere experiences. More work is needed to evaluate photochemical fractionation over a Pluto year. Condensation and aerosol trapping appear to have a major impact on the altitude profile of the isotope ratio in HCN. Since ALMA did not detect HC15N in Pluto's atmosphere, we conclude that condensation and aerosol trapping must be much more efficient for HC15N compared to HC14N. The large uncertainty in photochemical fractionation makes it difficult to use any potential current measurement of 14N/15N in N2 to determine the origin of Pluto's nitrogen. More work is needed to understand photochemical fractionation and to evaluate how condensation, sublimation and aerosol trapping will fractionate N2 and HCN.
Collapse
Affiliation(s)
- Kathleen Mandt
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Blvd., San Antonio, TX 78249, USA
- Johns Hopkins University Applied Physics Laboratory, 11100 Johns Hopkins Rd., Laurel, MD 20723, USA
| | - Adrienn Luspay-Kuti
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Mark Hamel
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Blvd., San Antonio, TX 78249, USA
| | - Kandis-Lea Jessup
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Vincent Hue
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Josh Kammer
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
| | - Rachael Filwett
- Space Science and Engineering Division, Southwest Research Institute, 6220 Culebra Rd., San Antonio, TX 78238, USA
- Department of Physics and Astronomy, University of Texas at San Antonio, One UTSA Blvd., San Antonio, TX 78249, USA
| |
Collapse
|