Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

(M)ethanological cycle of Titan

Mini-project ATPS

B.Sc. Planetary Sciences with Astronomy

3rd Year, Advanced Topics of Planetary Sciences

February 23rd, 2014

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Contents

TitanEnergy Balance

Atm. LayersAtm. ProfileRadiation BudgetEnergy Budget

Oceans & LakesPolar lakes

T91 Fly-byLigeia MareLake bathymetryEvaporation

Rainfall/Run-offRainfallITCZ

Conclusions

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Outline

TitanEnergy Balance

Atm. LayersAtm. ProfileRadiation BudgetEnergy Budget

Oceans & LakesPolar lakes

T91 Fly-byLigeia MareLake bathymetryEvaporation

Rainfall/Run-offRainfallITCZ

Conclusions

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Titan

Titan (Saturn VI)

The largest of Saturn’s natural satellites1.5 times the diameter of the Moon

Hydrocarbons

Surface and atmospheric hydrocarbonMethane (CH4) of solar system originsEthane (C2H6) rainfall

Hydrocarbons

Triple phase temperature range (solid, liquid, gas)Atmospheric photolysis of CH4 to C2H6

Oceans & Lakes as source of atmospheric content

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Outline

TitanEnergy Balance

Atm. LayersAtm. ProfileRadiation BudgetEnergy Budget

Oceans & LakesPolar lakes

T91 Fly-byLigeia MareLake bathymetryEvaporation

Rainfall/Run-offRainfallITCZ

Conclusions

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Titan Atmospheric Layers

Image Credit: NASA/JPL-Caltech

http://photojournal.jpl.nasa.gov/jpeg/PIA06160.jpg

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Atmospheric Profile

Figure Credit: Lunine et al. (1983)

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Radiation Budget

The generic longwave greybody/blackbody radiation:

GE = εBB = εσT 4 (1)

The radiation budget at planetary surface:

Rnet = SWbal + LWbal (2)

Radiation budget generic extension at planetary surface:

Rnet = (1−ρ)τswEs +(1−ε0)σT 40 +(εatm−1)σT 4

atm+ε (3)

This provides the constraint on the available energy forconduction, convection and vaporization processes at surface

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Energy Budget

2%10%

10%40%

30%100%

1% 113%

120% = 94K

15%

25%

70% = 82K

45%

Shortwave balance Longwave balance

Stratosphere

Troposphere

Figure Credit: recreated after McKay et al. (1991)

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Outline

TitanEnergy Balance

Atm. LayersAtm. ProfileRadiation BudgetEnergy Budget

Oceans & LakesPolar lakes

T91 Fly-byLigeia MareLake bathymetryEvaporation

Rainfall/Run-offRainfallITCZ

Conclusions

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

North Pole

Radar Image Credit: NASA/JPL-Caltech

http://www.ciclops.org//view media.php?id=39076

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

T91

Kraken Mare

Small lakes

Kraken Mare

Mývatn Lacus

Oneida Lacus

Waikare Lacus

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Ligeia Mare

Radar Image Credit: NASA/JPL-Caltech

http://www.ciclops.org//view media.php?id=39071&js=1

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Lake bathymetry radar altimetry

Figure Credit: Mastrogiuseppe et al. (2014)

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Lake bathymetry depth

Figure Credit: Mastrogiuseppe et al. (2014)

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Evaporation

Evaporation

20mm/week at poles1mm/week at equator

The vaporization heat adapted to Titan:

HL =naL

ηC (qs − qa) =

naL

ηCδq (4)

η the Avogadro’s numberL the latent heat of vaporization of methaneC the bulk transfer coefficientq the mole fraction of methane at liquid surface (saturatedstate: qs) and at a given height (typically few meters) in theatmosphere above (qa)

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Outline

TitanEnergy Balance

Atm. LayersAtm. ProfileRadiation BudgetEnergy Budget

Oceans & LakesPolar lakes

T91 Fly-byLigeia MareLake bathymetryEvaporation

Rainfall/Run-offRainfallITCZ

Conclusions

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Rainfall on Belet (-5N,255E)

Rainfall on Belet (-5N,255E)

The change of surface albedo from Cassini VIMS, darkeningafter a large cloud passed on the Belet Albedo feature, andbrightening again after some time.

Radar Image Credit: NASA/JPL-Caltech/SSI

http://www.titanexploration.com/TitanImages2011Plus/TitanImages2011.htm

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

ITCZ

Figure Credit: Tokano (2013)

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Outline

TitanEnergy Balance

Atm. LayersAtm. ProfileRadiation BudgetEnergy Budget

Oceans & LakesPolar lakes

T91 Fly-byLigeia MareLake bathymetryEvaporation

Rainfall/Run-offRainfallITCZ

Conclusions

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Conclusions

The (m)ethonological cycle, its energy budget andspatio-temporal dynamics are just starting to be discovered.

NowEvery additional fly-by of CassiniTreasure trove for Titan science

Future missions

I Rainfall: microwave sensor on-board orbiter/lander(TRMM type)

I Run-off: orbital radar altimeter(Magellan Venus radar type)

I Geomorphology: sub-clouds aerial Lidar altimeter +multi/hyperspectral (TSSM/Mongolfiere type)

I Energy budget: Thermal profiler in orbit, vessel onlakes/oceans (TSSM/TiME type)

Titan Meth. Cycle

Yann Chemin

Titan

Energy Balance

Atm. Layers

Atm. Profile

Radiation Budget

Energy Budget

Oceans & Lakes

Polar lakes

T91 Fly-by

Ligeia Mare

Lake bathymetry

Evaporation

Rainfall/Run-off

Rainfall

ITCZ

Conclusions

Thank You

Thank you

Radar Image Credit: PDS/NASA/JPL-Caltech