2018A&A...615A..97L


Query : 2018A&A...615A..97L

2018A&A...615A..97L - Astronomy and Astrophysics, volume 615A, 97-97 (2018/7-1)

Simulating the cloudy atmospheres of HD 209458 b and HD 189733 b with the 3D Met Office Unified Model.

LINES S., MAYNE N.J., BOUTLE I.A., MANNERS J., LEE G.K.H., HELLING C., DRUMMOND B., AMUNDSEN D.S., GOYAL J., ACREMAN D.M., TREMBLIN P. and KERSLAKE M.

Abstract (from CDS):


Aims. 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 and dynamics, 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 1 µm 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 HD 209458 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 250K 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.

Abstract Copyright: © ESO 2018

Journal keyword(s): planets and satellites: atmospheres - methods: numerical - hydrodynamics - radiative transfer - scattering - planets and satellites: gaseous planets

Simbad objects: 8

goto Full paper

goto View the references in ADS

Number of rows : 8
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 CoRoT-7b Pl 06 43 49.4690410679 -01 03 46.825797768           ~ 380 1
2 CD-38 3220b Pl 07 10 24.0606039387 -39 05 50.570553937           ~ 226 0
3 WASP-43b Pl 10 19 38.0089444408 -09 48 22.603103969           ~ 297 1
4 Kepler-7b Pl 19 14 19.5623271934 +41 05 23.365460942           ~ 186 1
5 BD+47 2846b Pl 19 28 59.3538131541 +47 58 10.216250846           ~ 337 1
6 HD 189733 BY* 20 00 43.7129433648 +22 42 39.073143456 9.241 8.578 7.648 7.126 6.68 K2V 816 1
7 HD 189733b Pl 20 00 43.7130382888 +22 42 39.071811263           ~ 1291 1
8 HD 209458b Pl 22 03 10.7729598762 +18 53 03.548248479           ~ 1707 1

To bookmark this query, right click on this link: simbad:objects in 2018A&A...615A..97L and select 'bookmark this link' or equivalent in the popup menu


2022.10.01-14:54:38

© Université de Strasbourg/CNRS

    • Contact