Preliminary results on the composition of Jupiter's troposphere in hot spot regions from the JIRAM/Juno instrument. Issue 10 (25th May 2017)

• Record Type: Journal Article
• Authors: Grassi, D.; Adriani, A.; Mura, A.; Dinelli, B. M.; Sindoni, G.; Turrini, D.; Filacchione, G.; Migliorini, A.; Moriconi, M. L.; Tosi, F.; Noschese, R.; Cicchetti, A.; Altieri, F.; Fabiano, F.; Piccioni, G.; Stefani, S.; Atreya, S.; Lunine, J.; Orton, G.; Ingersoll, A.; Bolton, S.; Levin, S.; Connerney, J.; Olivieri, A.; Amoroso, M.
• Is Part Of: Geophysical research letters. Volume 44:Issue 10(2017)
• Page Start: 4615
• Page End: 4624
• Publication Date: 2017-05-25
• Subjects: Jupiter -- hot spots -- spectroscopy; Geophysics -- Periodicals; Planets -- Periodicals; Lunar geology -- Periodicals; 550
• DOI: 10.1002/2017GL072841
• Languages: English
• ISSNs: 0094-8276

Abstract

Abstract: The Jupiter InfraRed Auroral Mapper (JIRAM) instrument on board the Juno spacecraft performed observations of two bright Jupiter hot spots around the time of the first Juno pericenter passage on 27 August 2016. The spectra acquired in the 4–5 µm spectral range were analyzed to infer the residual opacities of the uppermost cloud deck as well as the mean mixing ratios of water, ammonia, and phosphine at the approximate level of few bars. Our results support the current view of hot spots as regions of prevailing descending vertical motions in the atmosphere but extend this view suggesting that upwelling may occur at the southern boundaries of these structures. Comparison with the global ammonia abundance measured by Juno Microwave Radiometer suggests also that hot spots may represent sites of local enrichment of this gas. JIRAM also identifies similar spatial patterns in water and phosphine contents in the two hot spots. Key Points: Hot spots are confirmed as very dry regions in the atmosphere of Jupiter Consistent spatial patterns are found in the distributions of water and phosphine Ammonia shows local enhancements in the southern parts of hot spots