Lower atmosphere and pressure evolution on Pluto from ground-based stellar occultations, 1988-2016

Publication date: 
Main author: 
Meza, E.
IAA authors: 
Ortiz, J. L.;Tirado, A. Castro;Duffard, R.;Morales, N.;Santos-Sanz, P.
Meza, E.;Sicardy, B.;Assafin, M.;Ortiz, J. L.;Bertrand, T.;Lellouch, E.;Desmars, J.;Forget, F.;Bérard, D.;Doressoundiram, A.;Lecacheux, J.;Oliveira, J. Marques;Roques, F.;Widemann, T.;Colas, F.;Vachier, F.;Renner, S.;Leiva, R.;Braga-Ribas, F.;Benedetti-Rossi, G.;Camargo, J. I. B.;Dias-Oliveira, A.;Morgado, B.;Gomes-Júnior, A. R.;Vieira-Martins, R.;Behrend, R.;Tirado, A. Castro;Duffard, R.;Morales, N.;Santos-Sanz, P.;Jelínek, M.;Cunniffe, R.;Querel, R.;Harnisch, M.;Jansen, R.;Pennell, A.;Todd, S.;Ivanov, V. D.;Opitom, C.;Gillon, M.;Jehin, E.;Manfroid, J.;Pollock, J.;Reichart, D. E.;Haislip, J. B.;Ivarsen, K. M.;LaCluyze, A. P.;Maury, A.;Gil-Hutton, R.;Dhillon, V.;Littlefair, S.;Marsh, T.;Veillet, C.;Bath, K. -L.;Beisker, W.;Bode, H. -J.;Kretlow, M.;Herald, D.;Gault, D.;Kerr, S.;Pavlov, H.;Faragó, O.;Klös, O.;Frappa, E.;Lavayssière, M.;Cole, A. A.;Giles, A. B.;Greenhill, J. G.;Hill, K. M.;Buie, M. W.;Olkin, C. B.;Young, E. F.;Young, L. A.;Wasserman, L. H.;Devogèle, M.;French, R. G.;Bianco, F. B.;Marchis, F.;Brosch, N.;Kaspi, S.;Polishook, D.;Manulis, I.;Ait Moulay Larbi, M.;Benkhaldoun, Z.;Daassou, A.;El Azhari, Y.;Moulane, Y.;Broughton, J.;Milner, J.;Dobosz, T.;Bolt, G.;Lade, B.;Gilmore, A.;Kilmartin, P.;Allen, W. H.;Graham, P. B.;Loader, B.;McKay, G.;Talbot, J.;Parker, S.;Abe, L.;Bendjoya, Ph.;Rivet, J. -P.;Vernet, D.;Di Fabrizio, L.;Lorenzi, V.;Magazzú, A.;Molinari, E.;Gazeas, K.;Tzouganatos, L.;Carbognani, A.;Bonnoli, G.;Marchini, A.;Leto, G.;Sanchez, R. Zanmar;Mancini, L.;Kattentidt, B.;Dohrmann, M.;Guhl, K.;Rothe, W.;Walzel, K.;Wortmann, G.;Eberle, A.;Hampf, D.;Ohlert, J.;Krannich, G.;Murawsky, G.;Gährken, B.;Gloistein, D.;Alonso, S.;Román, A.;Communal, J. -E.;Jabet, F.;deVisscher, S.;Sérot, J.;Janik, T.;Moravec, Z.;Machado, P.;Selva, A.;Perelló, C.;Rovira, J.;Conti, M.;Papini, R.;Salvaggio, F.;Noschese, A.;Tsamis, V.;Tigani, K.;Barroy, P.;Irzyk, M.;Neel, D.;Godard, J. P.;Lanoiselée, D.;Sogorb, P.;Vérilhac, D.;Bretton, M.;Signoret, F.;Ciabattari, F.;Naves, R.;Boutet, M.;De Queiroz, J.;Lindner, P.;Lindner, K.;Enskonatus, P.;Dangl, G.;Tordai, T.;Eichler, H.;Hattenbach, J.;Peterson, C.;Molnar, L. A.;Howell, R. R.
Astronomy and Astrophysics
Publication type: 
Context. The tenuous nitrogen (N<SUB>2</SUB>) 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. <BR /> 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. <BR /> 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). <BR /> 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 N<SUB>2</SUB> 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.
ADS Bibcode: 
methods: observational;methods: data analysis;planets and satellites: atmospheres;techniques: photometric;planets and satellites: physical evolution;planets and satellites: terrestrial planets;Astrophysics - Earth and Planetary Astrophysics