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Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone, KU Leuven Center for mathematical Plasma-Astrophysics (CmPA), Institute of Astronomy (IvS) + KU Leuven IDO group Rony Keppens (CmPA), Leen Decin , Olivia Venot, Pieter Degroote (IvS), Shaun Carl, Minh Tho Nguyen, Thi Huyen Nguyen, Aysha Roshni Hashim (Chemistry) Vincent van Eylen (Aarhus),

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Page 1: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Weather on strange new worlds: A troposphere benchmark model

for a tidally locked terrestrial planet

Ludmila Carone, KU LeuvenCenter for mathematical Plasma-Astrophysics

(CmPA), Institute of Astronomy (IvS)

+ KU Leuven IDO groupRony Keppens (CmPA),

Leen Decin , Olivia Venot, Pieter Degroote (IvS), Shaun Carl, Minh Tho Nguyen, Thi Huyen

Nguyen, Aysha Roshni Hashim (Chemistry)Vincent van Eylen (Aarhus),

Page 2: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,
Page 3: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Held &Suarez 1994: 'fruitfly' of climate research – Fluid Dynamics

• Navier-Stokes equation under hydrostatic equilibrium (HPE)

Dv⃗ hDt

+(2Ω⃗× v⃗ )h+1ρ ∇ h p=Fh

∂ p∂ z

+ρg=0

Horizontal momentum equation

Hydrostatic equilibrium

Continuity equation∇ h⋅v⃗h+

∂ w∂ z

=01ρDρDt

+

DDt

= ∂∂ t

+ v⃗h⋅∇ h+w∂∂ z

Page 4: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Held &Suarez 1994: 'fruitfly' of climate research – Thermal forcing

• Navier-Stokes equation (HPE)

• Newtonian relaxation towards equilibrium temperature

DTDt

=−[T−T eq ]

τ rad

40 d for Earth

Page 5: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Temperature forcing for Earth

200 K stratosphere

Page 6: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Held &Suarez 1994: 'fruitfly' of climate research – Surface <-> Atmosphere friction

• Navier-Stokes equation (HPE)

• Newtonian relaxation towards equilibrium temperature

• Rayleigh friction between surface and atmosphere

F⃗h=k v v⃗ h kv=1 day-1...0

p=1000-700 mbar

Page 7: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Temperature forcing for Earth

200 K stratosphere

Rayleigh friction

Page 8: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Adaptation for tidally locked dayside

x I 0 (1−α) determines Teff,P

Page 9: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Assuming leaky greenhouse model+skin layer concept

T s=(2

2−ϵ)

1 /4

T eff , P T tropopause=0.51 /4T eff , P

e.g. Pierrehumbert 2010

e.g. J. Marshall 2008

0.8 for Earth

Page 10: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

At the nightside and terminator: Martian polar night scenario

• Equilibrium between condensation and IR-back radiation of atmosphere

T cond=T ref

1−RT refL

ln (ppref

)

Smith, 2008, Spacecraft Observationsof the Martian Atmosphere, Annu. Rev. Earth Planet. Sci. 2008. 36:191–219

Tref

=77 K @ pref

=1000 mbar for N2

Page 11: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Tidally locked dayside rad.-conv.-Teq

Earth-like atmosphere and insolation

α=0.3I 0=1368W /m2

T ( p)=max (T s(pps

)R / c p

,T tropopause)

τrad=cP psg 4σ T 3

=4d−813d

Page 12: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Put it on a Super-Earth

If it exists, it lies in the habitable zone of the M dwarf star

MGl581g=3.1M Earth→ R pl=1.45R Earth ; g=14.3m /s2

Prot

=Porb

=36.5, 10d,... days,

Page 13: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Dynamics on terrestrial Super-EarthsProt=10 d Prot=36 d

p=10

00 m

bar

p=52

5 m

bar

1000 d time average∇T p=525mb≈25 K ∇T p=525mb≈10K

Page 14: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Dynamics on terrestrial Super-EarthsProt=10 d Prot=36 d

p=10

00 m

bar

p=52

5 m

bar

1000 d time average cyclones

Page 15: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Cyclones are cloud/ precipitation generators

Cyclone near Iceland

Wiki commons

Page 16: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Dynamics on terrestrial Super-EarthsProt=10 d Prot=36 d

p=10

00 m

bar

p=52

5 m

bar

1000 d time average anticyclones

Page 17: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Anti-cyclones are cloud/precipitation dispersers

Anti-cyclone near South-Australia

Wiki-commons

Page 18: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Zalucha 2013

• H2O atmosphere, P

rot=1.5 d, Hot regime, ps=1000 mbar

Page 19: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

KU Leuven Benchmark Prot=10 d

Prot

=10 days

Page 20: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Our benchmark P

rot=36.5 daysP

rot=10 days

Page 21: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Vertical temperature at anti-stellar point

36d10d

Page 22: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Thermal inversion-> Smog formation

BBC Weather

Page 23: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

Conclusion

• A tidally locked terrestrial planet benchmark with the same conceptional simplicity than the Held&Suarez benchmarko Fast, versatile, good for parameter study

• On average, nightside temperature does not drop very low (280-290 K)

• Dayside temperatures allow for liquid water (350-300 K)

• Substellar point is upwelling region (cloud formation)

• For slow rotation (>30 d), Cyclones at mid-latitude in mid-troposphere (cloud formation, reduced horiz. diffusion)

• Thermal inversion at the surface (hinders vertical diffusion)

Page 24: Weather on strange new worlds: A troposphere benchmark ... · Weather on strange new worlds: A troposphere benchmark model for a tidally locked terrestrial planet Ludmila Carone,

In preparation:

Carone et al., Connecting the dots: A versatile terrestrial planet benchmark for tidally locked Super-Earths with Earth-like atmospheres, MNRAS