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dc.contributor.authorLines, Stefan
dc.contributor.authorMayne, Nathan
dc.contributor.authorBoutle, I. A.
dc.contributor.authorManners, J.
dc.contributor.authorLee, Graham Kim Huat
dc.contributor.authorHelling, Christiane
dc.contributor.authorDrummond, B.
dc.contributor.authorAmundsen, D. S.
dc.contributor.authorGoyal, J.
dc.contributor.authorAcreman, D. M.
dc.contributor.authorTremblin, P.
dc.contributor.authorKerslake, M.
dc.date.accessioned2018-06-07T08:30:07Z
dc.date.available2018-06-07T08:30:07Z
dc.date.issued2018-07
dc.identifier.citationLines , S , Mayne , N , Boutle , I A , Manners , J , Lee , G K H , Helling , C , Drummond , B , Amundsen , D S , Goyal , J , Acreman , D M , Tremblin , P & Kerslake , M 2018 , ' Simulating the cloudy atmospheres of HD 209458 b and HD 189733 b with the 3D Met Office Unified Model ' , Astronomy & Astrophysics , vol. 615 , A97 . https://doi.org/10.1051/0004-6361/201732278en
dc.identifier.issn0004-6361
dc.identifier.otherPURE: 253290853
dc.identifier.otherPURE UUID: c5953ef9-a045-4d06-9b57-dc04aa3fd8a0
dc.identifier.otherScopus: 85047192775
dc.identifier.otherWOS: 000439526600006
dc.identifier.urihttp://hdl.handle.net/10023/13790
dc.description.abstractAims.To understand and compare the 3D atmospheric structure of HD 209458 b and HD 189733 b, focusing on the formation and distribution of cloud particles, as well as their feedback on the dynamics and thermal profile. Methods. We coupled the 3D Met Office Unified Model (UM), including detailed treatments of atmospheric radiative transfer anddynamics, to a kinetic cloud formation scheme. The resulting model self–consistently solves for the formation of condensation seeds,surface growth and evaporation, gravitational settling and advection, cloud radiative feedback via absorption, and crucially, scattering. We used fluxes directly obtained from the UM to produce synthetic spectral energy distributions and phase curves. Results. Our simulations show extensive cloud formation in both HD 209458 b and HD 189733 b. However, cooler temperatures in the latter result in higher cloud particle number densities. Large particles, reaching 1μm in diameter, can form due to high particle growth velocities, and sub-μm particles are suspended by vertical flows leading to extensive upper-atmosphere cloud cover. A combination of meridional advection and efficient cloud formation in cooler high latitude regions, results in enhanced cloud coverage for latitudes above 30° and leads to a zonally banded structure for all our simulations. The cloud bands extend around the entire planet, for HD209458 b and HD 189733 b, as the temperatures, even on the day side, remain below the condensation temperature of silicates and oxides. Therefore, the simulated optical phase curve for HD 209458 b shows no ‘offset’, in contrast to observations. Efficient scattering of stellar irradiation by cloud particles results in a local maximum cooling of up to 250 K in the upper atmosphere, and an advection-driven fluctuating cloud opacity causes temporal variability in the thermal emission. The inclusion of this fundamental cloud-atmosphere radiative feedback leads to significant differences with approaches neglecting these physical elements, which have been employed to interpret observations and determine thermal profiles for these planets. This suggests that readers should be cautious of interpretations neglecting such cloud feedback and scattering, and that the subject merits further study.
dc.format.extent27
dc.language.isoeng
dc.relation.ispartofAstronomy & Astrophysicsen
dc.rights© 2018, ESO. This work has been made available online in accordance with the publisher’s policies. This is the author created, accepted version manuscript following peer review and may differ slightly from the final published version. The final published version of this work is available at https://doi.org/10.1051/0004-6361/201732278en
dc.subjectMethods: numericalen
dc.subjectHydrodynamicsen
dc.subjectRadiative transferen
dc.subjectScatteringen
dc.subjectPlanets and satellites: atmospheresen
dc.subjectPlanets and satellites: gaseous planetsen
dc.subjectQB Astronomyen
dc.subjectQC Physicsen
dc.subjectSpace and Planetary Scienceen
dc.subjectAstronomy and Astrophysicsen
dc.subjectNDASen
dc.subject.lccQBen
dc.subject.lccQCen
dc.titleSimulating the cloudy atmospheres of HD 209458 b and HD 189733 b with the 3D Met Office Unified Modelen
dc.typeJournal articleen
dc.description.versionPostprinten
dc.contributor.institutionUniversity of St Andrews.School of Physics and Astronomyen
dc.contributor.institutionUniversity of St Andrews.St Andrews Centre for Exoplanet Scienceen
dc.identifier.doihttps://doi.org/10.1051/0004-6361/201732278
dc.description.statusPeer revieweden
dc.identifier.urlhttps://arxiv.org/abs/1803.00226en


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