Understanding atmospheres across the Universe ATMO · across the Universe ATMO Pascal Tremblin – 32 years – 35 refereed ar>cles (11 as ﬁrst author) – 450 cita>ons – Co-supervision:

Understandingatmospheres

acrosstheUniverse

ATMO

PascalTremblin

–  32years–  35refereedar>cles(11asfirstauthor)–  450cita>ons–  Co-supervision:2PhDstudent,2masterprojects

–  Exper>se:atmosphericmodeling,numerical

simula>on,HPC,comparisonwithobserva>ons

2009 2012 2015 now

PhD:CEASaclay

3Dturbulenthydrodynamics

Postdoc:Exeter

Atmosphericmodel

Permanent:MaisondelaSimula>on

HPCHydrodynamics

Forhabitabilityandbio-marker

signatureForLoca>onandprocessesfor

planetforma>on

Ø Needtocharacterizeexoplanetproper>es:•  mass,radius

•  pressure/temperatureprofile

•  chemicalcomposi>on

Importanceofexoplanet-atmospherecharacteriza>on

ATMO–PascalTremblin 2/10



Thermohalineconvec>oninEarth’soceans

Challenge1:

•  Whydoexoplanets/Browndwarfs

emitstrongerintheinfraredthan

expected?

•  Conven>onalscenariofor20years:

Clouds?

•  Orfingeringconvec>oninducedby

chemicaltransi>one.g.CO/CH4?(1D

atmo:Tremblinetal.2015,2016)



Challenge1:



expected?


Clouds?




Challenge2:

•  Whydoirradiatedexoplanetshave

inflatedradii?

•  Norobustmechanismfor20years

(possiblymagne>cfields)

•  Orjustcircula>onandver>cal

advec>onofpoten>altemperature?

(2Datmo:Tremblinetal.2017)



Challenge2:

•  Whydoirradiatedexoplanetshave

inflatedradii?

•  Norobustmechanismfor20years

(possiblymagne>cfields?)

•  Orjustcircula>onandver>cal

advec>onofpoten>altemperature?

(Tremblinetal.2017)

Ø  Verypromisingbutalotofworks>llneedtobedone!

Ø  Mandatorytohaverobustmodelstointerpretobserva>ons

Challenge1:



expected?


Clouds?




UnderstandingatmospheresacrosstheUniverse

ATMO

Ø Needabecerunderstandingofthephysicalprocessespresentinatmospheres:theATMOproject

WP1:Fingeringconvec>onin

Ap/BpstarWP2:Fingeringconvec>onin

Browndwarfsandnon-

irradiatedexoplanets

WP3:Fingeringconvec>on

andcircula>onin



Small-scale

Numericalsimula>onSmall-scaletolarge-scale

Adap>veMeshRefinement

Large-scale

Globalcircula>onModel


ATMO

Ø Needabecerunderstandingofthephysicalprocessespresentinatmospheres:theATMOproject

WP1:Fingeringconvec>onin

Ap/BpstarWP2:Fingeringconvec>onin

Browndwarfsandnon-


WP3:Fingeringconvec>on

andcircula>onin



2018 2023ATMOproject

E-Elt

2025

JWSTlaunch

WP1

Fingeringconvec>oninAp/Bpstar

WP1:Ap/Bp

star

WP2:BDs/

exoplanets

WP3:Irradiated

exoplanets

Stateoftheart

•  applica>onoftheboussinesqmodelof

Brownetal.(2013),Garaudetal.(2015)

Challenges

•  Stra>fica>oneffect?

•  Astrophysicalregime?(viscousscaletoo

small)

Newapproach

•  Designanewrobusthydrodynamicsolver

forstra>fiedflow

•  TakeadvantageofnewHPCarchitecture

togetclosertotheastrophysicalregime


Appliedmathsbreakthrough(coll.S.Kokh)

•  Lagrange-remapsolver

•  Well-balancedforgravity

•  HighorderwithMOOD

GPUs/XeonPhiwithKokkoslibrary

(Coll.P.Kestener)

PI,Postdoc1,HPCEngineer

WP2

Fingeringconvec>oninBrowndwarfsandexoplanets

WP1:Ap/Bp

star

WP2:BDs/

exoplanets

WP3:Irradiated

exoplanets

Stateoftheart

•  (1D)Fingeringconvec>oninducedby

chemicalinstabili>esexplainsthespectral

reddening(Tremblinetal.2015,2016)

Challenges

•  Isthe3Dturbulentenergytransport

inducedbyfingeringconvec>onefficient

enough?

•  Istheextensionoftheturbulentzonebig

enough?

Newapproach

•  UseAdapta>veMeshRefinementto

resolvethesmallscalefingersandthe

extensionoftheturbulentregion

•  Dynamicalstudyandparametriza>onof

chemicalinstabili>esfor1Dmodel


PI,PhD1,HPCEngineer

Preliminaryresultof

thedynamicalCO/CH4

instability

WP3

Fing.convec>onandcircula>oninirradiatedexoplanets

WP1:Ap/Bp

star

WP2:BDs/

exoplanets

WP3:Irradiated

exoplanets

Stateoftheart

•  2Dsteadystatecircula>onmodelexpains

theinflatedradii(Tremblinetal.2017)

Challenges

•  Whataboutthe3Dsteadycircula>on?

•  Andtheinterplaywithfing.convec>on?

Newapproach

•  Usetheefficencyofrecentcircula>on

model(Dynamico)toreachthe3Dsteady

state

•  Studyfingeringconvec>oninaforced

shearflowboxmodel,extensionofthe

parametriza>onforglobalmodels


PI,PhD2,HPCEngineer

Scalingofthenew

cirula>onmodel

Dynamico

WP1:Ap/Bp

star

WP2:BDs/

exoplanets

WP3:Irradiated

exoplanets



ATMO

LowestrisksWP2/3:

•  Parametriza>onoftheinstability

•  Implementa>oninglobal1D/3D

atmosphericmodels

HighestrisksWP1:

stra>fiedhydro-solver

•  Lagrange-remap->low-machsolver

•  Well-balancedgravity->relaxa>on

•  HighorderMOOD->2ndorderscheme

WP1:Ap/Bp

star

WP2:BDs/

exoplanets

WP3:Irradiated

exoplanets

ATMO–PascalTremblin


ATMO

10/10

2018 2023ATMOproject

E-Elt

2025

JWSTlaunch

Team:Posdoc1,PhD1,PhD2

PI,HPCEngineer

(Hostins>tute:CEASalcay)

Budget:

Manpower(60%),HPCinvestments(11%)

Travel,publica>ons(9%)Overheads(20%)

Deliverables

•  Aninnova>vesolverforstra>fied

hydrodynamics

•  Parametriza>onoffingering

convec>onforglobalmodels

•  Produceexoplanetsspectra,phase

curvesforfutureJWST/E-elt

observa>ons(PIassociatedtoMIRI

consor>um)

Transferinotherfields

•  Applica>onofthesolverfor

oceanicdynamics

�2.0 �1.5 �1.0 �0.5 0.0 0.5 1.0 1.5 2.0

J-H band Color

10

15

20

25

Jba

ndM

agni

tude

Stars

Brown Dwarfs

Exoplanets


?

models

«red»spectra


Whydoexoplanets/Browndwarfsemit

strongerintheinfraredthanexpected?

�2.0 �1.5 �1.0 �0.5 0.0 0.5 1.0 1.5 2.0

J-H band Color

10

15

20

25

Jba

ndM

agni

tude

Stars

Brown Dwarfs

Exoplanets


?

models

«red»spectra




Clouds?

orfingeringconvec>on?

(Tremblinetal.2015,2016)

�2.0 �1.5 �1.0 �0.5 0.0 0.5 1.0 1.5 2.0

J-H band Color

10

15

20

25

Jba

ndM

agni

tude

Stars

Brown Dwarfs

Exoplanets


?

models

«red»spectra




Clouds?



models

?Inflatedradii

Whydoirradiatedexoplanetshave

inflatedradii?

�2.0 �1.5 �1.0 �0.5 0.0 0.5 1.0 1.5 2.0

J-H band Color

10

15

20

25

Jba

ndM

agni

tude

Stars

Brown Dwarfs

Exoplanets


?

models

«red»spectra




Clouds?



models

?Inflatedradii

Whydoirradiatedexoplanetshave

inflatedradii?

Magne>cfields?

orcircula>on?

(Tremblinetal.2017)

Documents

Understanding atmospheres across the Universe ATMO · across the Universe ATMO Pascal Tremblin – 32 years – 35 refereed ar>cles (11 as ﬁrst author) – 450 cita>ons – Co-supervision: