dc.contributor.author | Drummond, B | |
dc.contributor.author | Mayne, NJ | |
dc.contributor.author | Manners, J | |
dc.contributor.author | Carter, A | |
dc.contributor.author | Boutle, I | |
dc.contributor.author | Baraffe, I | |
dc.contributor.author | Hebrard, E | |
dc.contributor.author | Tremblin, P | |
dc.contributor.author | Sing, D | |
dc.contributor.author | Amundsen, D | |
dc.contributor.author | Acreman, D | |
dc.date.accessioned | 2018-11-19T14:13:22Z | |
dc.date.issued | 2018-03-15 | |
dc.description.abstract | We present a study of the effect of wind-driven advection on the chemical composition of hot-Jupiter atmospheres using a fully consistent 3D hydrodynamics, chemistry, and radiative transfer code, the Met Office Unified Model (UM). Chemical modeling of exoplanet atmospheres has primarily been restricted to 1D models that cannot account for 3D dynamical processes. In this work, we couple a chemical relaxation scheme to the UM to account for the chemical interconversion of methane and carbon monoxide. This is done consistently with the radiative transfer meaning that departures from chemical equilibrium are included in the heating rates (and emission) and hence complete the feedback between the dynamics, thermal structure, and chemical composition. In this Letter, we simulate the well studied atmosphere of HD 209458b. We find that the combined effect of horizontal and vertical advection leads to an increase in the methane abundance by several orders of magnitude, which is directly opposite to the trend found in previous works. Our results demonstrate the need to include 3D effects when considering the chemistry of hot-Jupiter atmospheres. We calculate transmission and emission spectra, as well as the emission phase curve, from our simulations. We conclude that gas-phase nonequilibrium chemistry is unlikely to explain the model–observation discrepancy in the 4.5 μm Spitzer/IRAC channel. However, we highlight other spectral regions, observable with the James Webb Space Telescope, where signatures of wind-driven chemistry are more prominant. | en_GB |
dc.description.sponsorship | This work is partly
supported by the European Research Council under the
European Community’s Seventh Framework Programme
(FP7/2007-2013 Grant Agreement No. 320478-TOFU and
No. 336792-CREATES). N.J.M. is partially funded by a
Leverhulme Trust Research Project Grant. J.M. and I.A.B.
acknowledge the support of a Met Office Academic Partnership
secondment. A.L.C. is funded by an STFC studentship. D.S.A.
acknowledges support from the NASA Astrobiology Program
through the Nexus for Exoplanet System Science. This work
used the DiRAC Complexity system, operated by the
University of Leicester, which forms part of the STFC DiRAC
HPC Facility (www.dirac.ac.uk). This equipment is funded by
BIS National E-Infrastructure capital grant ST/K000373/1 and
STFC DiRAC Operations grant ST/K0003259/1. DiRAC is
part of the National E-Infrastructure. This work also used the
University of Exeter Supercomputer ISCA. | en_GB |
dc.identifier.citation | Volume 855 (2), article number L31 | en_GB |
dc.identifier.uri | http://hdl.handle.net/10871/34820 | |
dc.language.iso | en | en_GB |
dc.publisher | American Astronomical Society | en_GB |
dc.rights | © 2018. The American Astronomical Society. All rights reserved. | en_GB |
dc.subject | planets and satellites: atmospheres | en_GB |
dc.subject | planets and satellites: composition | en_GB |
dc.subject | planets and satellites: gaseous planets | en_GB |
dc.title | Observable signatures of wind--driven chemistry with a fully consistent three dimensional radiative hydrodynamics model of HD 209458b | en_GB |
dc.type | Article | en_GB |
dc.date.available | 2018-11-19T14:13:22Z | |
dc.identifier.issn | 2041-8205 | |
pubs.declined | 2018-09-05T10:43:21.834+0100 | |
dc.description | This is the final version. | en_GB |
dc.description | Also available from IOP Publishing via the DOI in this record. | en_GB |
dc.identifier.journal | Astrophysical Journal Letters | en_GB |