Publications


Jupiter's auroral-related stratospheric heating and chemistry II: Analysis of IRTF-TEXES spectra measured in December 2014

ICARUS 300 (2018) 305-326

JA Sinclair, GS Orton, TK Greathouse, LN Fletcher, JI Moses, V Hue, PGJ Irwin


Jupiter's North Equatorial Belt expansion and thermal wave activity ahead of Juno's arrival

GEOPHYSICAL RESEARCH LETTERS 44 (2017) 7140-7148

LN Fletcher, GS Orton, JA Sinclair, P Donnelly, H Melin, JH Rogers, TK Greathouse, Y Kasaba, T Fujiyoshi, TM Sato, J Fernandes, PGJ Irwin, RS Giles, AA Simon, MH Wong, M Vedovato


A rotating annulus driven by localized convective forcing: a new atmosphere-like experiment

EXPERIMENTS IN FLUIDS 58 (2017) ARTN 75

H Scolan, PL Read


A precise optical transmission spectrum of the inflated exoplanet WASP-52b

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 470 (2017) 742-754

T Louden, PJ Wheatley, PGJ Irwin, J Kirk, I Skillen


D/H Ratios on Saturn and Jupiter from Cassini CIRS

ASTRONOMICAL JOURNAL 154 (2017) ARTN 178

JDR Pierel, CA Nixon, E Lellouch, LN Fletcher, GL Bjoraker, RK Achterberg, B Bezard, BE Hesman, PGJ Irwin, FM Flasar


Space weathering effects in Diviner Lunar Radiometer multispectral infrared measurements of the lunar Christiansen Feature: Characteristics and mitigation

ICARUS 283 (2017) 343-351

PG Lucey, BT Greenhagen, E Song, JA Arnold, M Lemelin, KD Hanna, NE Bowles, TD Glotch, DA Paige


Phase synchronization of baroclinic waves in a differentially heated rotating annulus experiment subject to periodic forcing with a variable duty cycle

Chaos 27 (2017)

PL Read, X Morice-Atkinson, EJ Allen, AA Castrejón-Pita

© 2017 Author(s). A series of laboratory experiments in a thermally driven, rotating fluid annulus are presented that investigate the onset and characteristics of phase synchronization and frequency entrainment between the intrinsic, chaotic, oscillatory amplitude modulation of travelling baroclinic waves and a periodic modulation of the (axisymmetric) thermal boundary conditions, subject to timedependent coupling. The time-dependence is in the form of a prescribed duty cycle in which the periodic forcing of the boundary conditions is applied for only a fraction δ of each oscillation. For the rest of the oscillation, the boundary conditions are held fixed. Two profiles of forcing were investigated that capture different parts of the sinusoidal variation and δ was varied over the range 0:1 ≤ δ ≤ 1. Reducing δ was found to act in a similar way to a reduction in a constant coupling coefficient in reducing the width of the interval in forcing frequency or period over which complete synchronization was observed (the "Arnol'd tongue") with respect to the detuning, although for the strongest pulse-like forcing profile some degree of synchronization was discernible even at δ = 0:1. Complete phase synchronization was obtained within the Arnol'd tongue itself, although the strength of the amplitude modulation of the baroclinic wave was not significantly affected. These experiments demonstrate a possible mechanism for intraseasonal and/or interannual "teleconnections" within the climate system of the Earth and other planets that does not rely on Rossby wave propagation across the planet along great circles.


HST/WFC3 observations of Uranus' 2014 storm clouds and comparison with VLT/SINFONI and IRTF/Spex observations

ICARUS 288 (2017) 99-119

PGJ Irwin, MH Wong, AA Simon, GS Orton, D Toledo


Regimes of Axisymmetric Flow and Scaling Laws in a Rotating Annulus with Local Convective Forcing

Fluids 2 (2017) 41-41

S Wright, S Su, H Scolan, R Young, P Read


The thermal structure of the Venus atmosphere: Intercomparison of Venus Express and ground based observations of vertical temperature and density profiles

ICARUS 294 (2017) 124-155

SS Limaye, S Lebonnois, A Mahieux, M Paetzold, S Bougher, S Bruinsma, S Chamberlain, RT Clancy, J-C Gerard, G Gilli, D Grassi, R Haus, M Herrmann, T Imamura, E Kohler, P Krause, A Migliorini, F Montmessin, C Pere, M Persson, A Piccialli, M Rengel, A Rodin, B Sandor, M Sornig, H Svedhem, S Tellmann, P Tanga, AC Vandaele, T Widemann, CF Wilson, I Mueller-Wodarg, L Zasova


Forward and inverse kinetic energy cascades in Jupiter's turbulent weather layer

NATURE PHYSICS 13 (2017) 1135-+

RMB Young, PL Read


Discovery of a warm, dusty giant planet around HIP 65426

Astronomy & Astrophysics 605 (2017) L9-L9

G Chauvin, S Desidera, A-M Lagrange, A Vigan, R Gratton, M Langlois, M Bonnefoy, J-L Beuzit, M Feldt, D Mouillet, M Meyer, A Cheetham, B Biller, A Boccaletti, V D’Orazi, R Galicher, J Hagelberg, A-L Maire, D Mesa, J Olofsson, M Samland, TOB Schmidt, E Sissa, M Bonavita, B Charnay, M Cudel, S Daemgen, P Delorme, P Janin-Potiron, M Janson, M Keppler, H Le Coroller, R Ligi, GD Marleau, S Messina, P Mollière, C Mordasini, A Müller, S Peretti, C Perrot, L Rodet, D Rouan, A Zurlo, C Dominik, T Henning, F Menard, H-M Schmid, M Turatto, S Udry, F Vakili, L Abe, J Antichi, A Baruffolo, P Baudoz, J Baudrand, P Blanchard, A Bazzon, T Buey, M Carbillet, M Carle, J Charton, E Cascone, R Claudi, A Costille, A Deboulbe, V De Caprio, K Dohlen, D Fantinel, P Feautrier, T Fusco, P Gigan, E Giro, D Gisler, L Gluck, N Hubin, E Hugot, M Jaquet, M Kasper, F Madec, Y Magnard, P Martinez, D Maurel, D Le Mignant, O Möller-Nilsson, M Llored, T Moulin, A Origné, A Pavlov, D Perret, C Petit, J Pragt, P Puget, P Rabou, J Ramos, R Rigal, S Rochat, R Roelfsema, G Rousset, A Roux, B Salasnich, J-F Sauvage, A Sevin, C Soenke, E Stadler, M Suarez, L Weber, F Wildi, S Antoniucci, J-C Augereau, J-L Baudino, W Brandner, N Engler, J Girard, C Gry, Q Kral, T Kopytova, E Lagadec, J Milli, C Moutou, J Schlieder, J Szulágyi, C Thalmann, Z Wahhaj


Jupiter's para-H-2 distribution from SOFIA/FORCAST and Voyager/IRIS 17-37 mu m spectroscopy

ICARUS 286 (2017) 223-240

LN Fletcher, I de Pater, WT Reach, M Wong, GS Orton, PGJ Irwin, RD Gehrz


The PanCam Instrument for the ExoMars Rover

ASTROBIOLOGY 17 (2017) 511-541

AJ Coates, R Jaumann, AD Griffiths, CE Leff, N Schmitz, J-L Josset, G Paar, M Gunn, E Hauber, CR Cousins, RE Cross, P Grindrod, JC Bridges, M Balme, S Gupta, IA Crawford, P Irwin, R Stabbins, D Tirsch, JL Vago, T Theodorou, M Caballo-Perucha, GR Osinski, P Team


Linking the Climate and Thermal Phase Curve of 55 Cancri e

Astrophysical Journal 849 (2017)

M Hammond, RT Pierrehumbert

© 2017. The American Astronomical Society. All rights reserved. The thermal phase curve of 55 Cancri e is the first measurement of the temperature distribution of a tidally locked super-Earth, but raises a number of puzzling questions about the planet's climate. The phase curve has a high amplitude and peak offset, suggesting that it has a significant eastward hot-spot shift as well as a large day-night temperature contrast. We use a general circulation model to model potential climates, and investigate the relation between bulk atmospheric composition and the magnitude of these seemingly contradictory features. We confirm theoretical models of tidally locked circulation are consistent with our numerical model of 55 Cnc e, and rule out certain atmospheric compositions based on their thermodynamic properties. Our best-fitting atmosphere has a significant hot-spot shift and day-night contrast, although these are not as large as the observed phase curve. We discuss possible physical processes that could explain the observations, and show that night-side cloud formation from species such as SiO from a day-side magma ocean could potentially increase the phase curve amplitude and explain the observations. We conclude that the observations could be explained by an optically thick atmosphere with a low mean molecular weight, a surface pressure of several bars, and a strong eastward circulation, with night-side cloud formation a possible explanation for the difference between our model and the observations.


Jupiter's auroral-related stratospheric heating and chemistry I: Analysis of Voyager-IRIS and Cassini-CIRS spectra

ICARUS 292 (2017) 182-207

JA Sinclair, GS Orton, TK Greathouse, LN Fletcher, JI Moses, V Hue, PGJ Irwin


Moist convection and the 2010-2011 revival of Jupiter's South Equatorial Belt

ICARUS 286 (2017) 94-117

LN Fletcher, GS Orton, JH Rogers, RS Giles, AV Payne, PGJ Irwin, M Vedovato


Independent evolution of stratospheric temperatures in Jupiter's northern and southern auroral regions from 2014 to 2016

GEOPHYSICAL RESEARCH LETTERS 44 (2017) 5345-5354

JA Sinclair, GS Orton, TK Greathouse, LN Fletcher, C Tao, GR Gladstone, A Adriani, W Dunn, JI Moses, V Hue, PGJ Irwin, H Melin, RS Giles


ALMA detection and astrobiological potential of vinyl cyanide on Titan.

Science advances 3 (2017) e1700022-

MY Palmer, MA Cordiner, CA Nixon, SB Charnley, NA Teanby, Z Kisiel, PGJ Irwin, MJ Mumma

Recent simulations have indicated that vinyl cyanide is the best candidate molecule for the formation of cell membranes/vesicle structures in Titan's hydrocarbon-rich lakes and seas. Although the existence of vinyl cyanide (C2H3CN) on Titan was previously inferred using Cassini mass spectrometry, a definitive detection has been lacking until now. We report the first spectroscopic detection of vinyl cyanide in Titan's atmosphere, obtained using archival data from the Atacama Large Millimeter/submillimeter Array (ALMA), collected from February to May 2014. We detect the three strongest rotational lines of C2H3CN in the frequency range of 230 to 232 GHz, each with >4σ confidence. Radiative transfer modeling suggests that most of the C2H3CN emission originates at altitudes of ≳200 km, in agreement with recent photochemical models. The vertical column densities implied by our best-fitting models lie in the range of 3.7 × 1013 to 1.4 × 1014 cm-2. The corresponding production rate of vinyl cyanide and its saturation mole fraction imply the availability of sufficient dissolved material to form ~107 cell membranes/cm3 in Titan's sea Ligeia Mare.


Rayleigh scattering in the transmission spectrum of HAT-P-18b

MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 468 (2017) 3907-3916

J Kirk, PJ Wheatley, T Louden, AP Doyle, I Skillen, J McCormac, PGJ Irwin, R Karjalainen

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