@article {28389, title = {Lower atmosphere and pressure evolution on Pluto from ground-based stellar occultations, 1988-2016}, volume = {625}, year = {2019}, month = {2019/05/1}, pages = {A42}, abstract = {Context. The tenuous nitrogen (N2) atmosphere on Pluto undergoes strong seasonal effects due to high obliquity and orbital eccentricity, and has recently (July 2015) been observed by the New Horizons spacecraft.
Aims: The main goals of this study are (i) to construct a well calibrated record of the seasonal evolution of surface pressure on Pluto and (ii) to constrain the structure of the lower atmosphere using a central flash observed in 2015.
Methods: Eleven stellar occultations by Pluto observed between 2002 and 2016 are used to retrieve atmospheric profiles (density, pressure, temperature) between altitude levels of ~5 and ~380 km (i.e. pressures from ~ 10 μbar to 10 nbar).
Results: (i) Pressure has suffered a monotonic increase from 1988 to 2016, that is compared to a seasonal volatile transport model, from which tight constraints on a combination of albedo and emissivity of N2 ice are derived. (ii) A central flash observed on 2015 June 29 is consistent with New Horizons REX profiles, provided that (a) large diurnal temperature variations (not expected by current models) occur over Sputnik Planitia; and/or (b) hazes with tangential optical depth of ~0.3 are present at 4-7 km altitude levels; and/or (c) the nominal REX density values are overestimated by an implausibly large factor of ~20\%; and/or (d) higher terrains block part of the flash in the Charon facing hemisphere.}, keywords = {Astrophysics - Earth and Planetary Astrophysics, methods: data analysis, methods: observational, planets and satellites: atmospheres, planets and satellites: physical evolution, planets and satellites: terrestrial planets, techniques: photometric}, isbn = {0004-6361}, url = {https://ui.adsabs.harvard.edu/abs/2019A\&A...625A..42M}, author = {Meza, E. and Sicardy, B. and Assafin, M. and Ortiz, J. L. and Bertrand, T. and Lellouch, E. and Desmars, J. and Forget, F. and B{\'e}rard, D. and Doressoundiram, A. and Lecacheux, J. and Oliveira, J. Marques and Roques, F. and Widemann, T. and Colas, F. and Vachier, F. and Renner, S. and Leiva, R. and Braga-Ribas, F. and Benedetti-Rossi, G. and Camargo, J. I. B. and Dias-Oliveira, A. and Morgado, B. and Gomes-J{\'u}nior, A. R. and Vieira-Martins, R. and Behrend, R. and Tirado, A. Castro and Duffard, R. and Morales, N. and Santos-Sanz, P. and Jel{\'\i}nek, M. and Cunniffe, R. and Querel, R. and Harnisch, M. and Jansen, R. and Pennell, A. and Todd, S. and Ivanov, V. D. and Opitom, C. and Gillon, M. and Jehin, E. and Manfroid, J. and Pollock, J. and Reichart, D. E. and Haislip, J. B. and Ivarsen, K. M. and LaCluyze, A. P. and Maury, A. and Gil-Hutton, R. and Dhillon, V. and Littlefair, S. and Marsh, T. and Veillet, C. and Bath, K. -L. and Beisker, W. and Bode, H. -J. and Kretlow, M. and Herald, D. and Gault, D. and Kerr, S. and Pavlov, H. and Farag{\'o}, O. and Kl{\"o}s, O. and Frappa, E. and Lavayssi{\`e}re, M. and Cole, A. A. and Giles, A. B. and Greenhill, J. G. and Hill, K. M. and Buie, M. W. and Olkin, C. B. and Young, E. F. and Young, L. A. and Wasserman, L. H. and Devog{\`e}le, M. and French, R. G. and Bianco, F. B. and Marchis, F. and Brosch, N. and Kaspi, S. and Polishook, D. and Manulis, I. and Ait Moulay Larbi, M. and Benkhaldoun, Z. and Daassou, A. and El Azhari, Y. and Moulane, Y. and Broughton, J. and Milner, J. and Dobosz, T. and Bolt, G. and Lade, B. and Gilmore, A. and Kilmartin, P. and Allen, W. H. and Graham, P. B. and Loader, B. and McKay, G. and Talbot, J. and Parker, S. and Abe, L. and Bendjoya, Ph. and Rivet, J. -P. and Vernet, D. and Di Fabrizio, L. and Lorenzi, V. and Magazz{\'u}, A. and Molinari, E. and Gazeas, K. and Tzouganatos, L. and Carbognani, A. and Bonnoli, G. and Marchini, A. and Leto, G. and Sanchez, R. Zanmar and Mancini, L. and Kattentidt, B. and Dohrmann, M. and Guhl, K. and Rothe, W. and Walzel, K. and Wortmann, G. and Eberle, A. and Hampf, D. and Ohlert, J. and Krannich, G. and Murawsky, G. and G{\"a}hrken, B. and Gloistein, D. and Alonso, S. and Rom{\'a}n, A. and Communal, J. -E. and Jabet, F. and deVisscher, S. and S{\'e}rot, J. and Janik, T. and Moravec, Z. and Machado, P. and Selva, A. and Perell{\'o}, C. and Rovira, J. and Conti, M. and Papini, R. and Salvaggio, F. and Noschese, A. and Tsamis, V. and Tigani, K. and Barroy, P. and Irzyk, M. and Neel, D. and Godard, J. P. and Lanoisel{\'e}e, D. and Sogorb, P. and V{\'e}rilhac, D. and Bretton, M. and Signoret, F. and Ciabattari, F. and Naves, R. and Boutet, M. and De Queiroz, J. and Lindner, P. and Lindner, K. and Enskonatus, P. and Dangl, G. and Tordai, T. and Eichler, H. and Hattenbach, J. and Peterson, C. and Molnar, L. A. and Howell, R. R.} }