Glaciations on Mars:response to orbital variations
inferred from climate modelling,and comparison with Earth.
J.-B. Madeleine1 ([email protected])F. Forget1, J. W. Head2, F. Montmessin3, S. Bonelli4
1Laboratoire de Météorologie Dynamique (LMD), CNRS/UPMC/IPSL, France2Brown University, Providence RI 02912, USA3Service d’Aéronomie, CNRS/UVSQ/IPSL, France4Laboratoire des Sciences du Climat et de l'Environnement
(LSCE), IPSL/UMR CEA-CNRS 1572/UVSQ, France.
With the help of Pierre-Yves Meslin, Ehouarn Millour and Cédric Pilorget
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Two glacial climate systems
Atmosphere
Cryosphere (ice sheets and glaciers)
Glacier bed
External controls(orbital parameters
and solar variability)
Internal controls
(Plate tectonics, magnetic field)
Ocean
Biosphere(includinghumans)
Adapted fromAndrews (2006)
Earth and MarsClimate System
(10 to 106 year time scale)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Two glacial climate systems
Atmosphere
Cryosphere (ice sheets and glaciers)
Glacier bed
External controls(orbital parameters
and solar variability)
Internal controls
(Plate tectonics, magnetic field)
Ocean
Biosphere(includinghumans)
Adapted fromAndrews (2006)
Earth and MarsClimate System
(10 to 106 year time scale)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Orbital parameters of Earth
Adapted from Paillard et al. (1996)
EARTH
Today:ε = 23.5°e 0.017∼
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Orbital parameters of Mars
Adapted from Laskar et al. (2002)
MARSEarth
Earth
Today:ε = 25.2°e 0.093∼
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Two glacial climate systems
Atmosphere
Cryosphere (ice sheets and glaciers)
Glacier bed
External controls(orbital parameters
and solar variability)
Internal controls
(Plate tectonics, magnetic field)
Ocean
Biosphere(includinghumans)
Adapted fromAndrews (2006)
Earth and MarsClimate System
(10 to 106 year time scale)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Two glacial climate systems
Atmosphere
Cryosphere (ice sheets and glaciers)
Glacier bed
External controls(orbital parameters
and solar variability)
Internal controls
(Plate tectonics, magnetic field)
Ocean
Biosphere(includinghumans)
Adapted fromAndrews (2006)
Earth and MarsClimate System
(10 to 106 year time scale)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Cryosphere - Atmosphere
Atmosphere CryosphereChanges inmass balance
Summertemperature
(ablation)
Precipitation(accumulation)
- Orbital parameters:Change the space-time distribution of insolation;
- Radiative transfer:Chemical species (CO2)and aerosols (dust and clouds) change surface temperature.
- Water sourcesFirst control on the amount of water vapor in the atmosphere;
- Lower atmosphere temperature
Controls the amount of water vapor;- Dynamics
Results in cross-front mixing of moisture and condensation;
- Condensation nucleiFavor cloud formation.
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Two glacial climate systems
Atmosphere
Cryosphere (ice sheets and glaciers)
Glacier bed
External controls(orbital parameters
and solar variability)
Internal controls
(Plate tectonics, magnetic field)
Ocean
Biosphere(includinghumans)
Adapted fromAndrews (2006)
Earth and MarsClimate System
(10 to 106 year time scale)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Two glacial climate systems
Atmosphere
Cryosphere (ice sheets and glaciers)
Glacier bed
External controls(orbital parameters
and solar variability)
Internal controls
(Plate tectonics, magnetic field)
Ocean
Biosphere(includinghumans)
Adapted fromAndrews (2006)
Earth and MarsClimate System
(10 to 106 year time scale)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Icethickness
LGM: 21 kyr Today
Contour intervalof 1 km Peltier et al. (1998)
Earth 21 kyr BP: Last Glacial Maximum (LGM)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Earth: CLIMBER-GREMLINS coupled model (S. Bonelli)
CLIMBER 2.3 (Petoukhov et al., 2000)
- climate model of intermediate complexity;- Fast enough to run simulations over thousands of years;- model the major features of the atmosphere-vegetation-ocean system;- Resolution: 51° in longitude, 10° in latitude.
Atmosphere
Icesheet
GREMLINS (Ritz et al., 1997)
- 3D thermo-mechanical ice sheet model;- predicts the vertical temperature profile, basal melting, ice dynamics and isostatic adjustment of bedrock;- Resolution: 45 km in longitude and latitude (cartesian grid)Siegert et al. (2005)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
CLIMBER 2.3 (Petoukhov et al., 2000)
- climate model of intermediate complexity;- Fast enough to run simulations over thousands of years;- model the major features of the atmosphere-vegetation-ocean system;- Resolution: 51° in longitude, 10° in latitude.
Model is forced by:1) The orbital parameters (Berger, 1978)2) The atmospheric CO2 content,
measured at the Vostok station(Petit et al., 1999)
3) The amount of dust deposition on the surface, which changes the albedo (Mahowald et al., 1999)
Earth: CLIMBER-GREMLINS coupled model (S. Bonelli)
Past CO2concentrations,
Vostok
LGM
Start ofthe run
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
LGMLGM TodaySummer Surface Temperatures (°C)
Earth: CLIMBER-GREMLINS coupled model (S. Bonelli)
LGM: ε=22.95° e=0.019 Today: ε=23.5° e=0.017
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
ObservationsObservations Coupled model results
Peltier et al. (1998)
Ice sheetheight (m)
Earth: CLIMBER-GREMLINS coupled model (S. Bonelli)
(Bonelli et al.,2009)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
ObservationsObservations Coupled model results
Peltier et al. (1998)
Ice sheetheight (m)
Earth: CLIMBER-GREMLINS coupled model (S. Bonelli)
(Bonelli et al.,2009)
Asymmetry over northern Asia
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Earth: Asymmetry over Asia: Dust deposition
(Mahowald et al., 2006)
Dust darkening effect (Krinner et al., 2006)
Earth: First conclusions
Glacial-interglacial periods are mainly controlled by summer surface temperatures;
Favorable conditions implied by the orbital parameters are amplified by the CO2 cycle (Eurasian glaciation);
Dust deposition on the seasonal snow cover results in low albedo and melting in northern Asia.
(Bonelli et al., 2009)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Mars: Late Amazonian (< 250–700 Myr) glaciations
Head et al. (2008)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
- The latitude dependent mantle (1): m thick layered deposits, above 50° (Head et al., 2003);- Northern mid-latitudes (3,4,5,6,7): valley glaciers and plateau glaciation, km thicknesses;- Tropical mountain glaciers (8): mountain glacial systems, episodes of advance and retreat;
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Head et al. (2005, 2008)
MARS EARTH
Tropical mountain glaciers (8): mountain glacial systems, episodes of advance and retreat;
Mars: Late Amazonian mid-latitude glaciation
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
MARS EARTH
Head et al. (2008)
Northern mid-latitudes (3,4,5,6,7): valley glaciers and plateau glaciation, km thicknesses;
Mars: Late Amazonian mid-latitude glaciation
Mars: The LMD/GCM
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Model
Observations
- 3D General Circulation Model;
- Dust cycle: based on a prescribed value of τdust;
- Water cycle: includes water vapor transport and condensation predicted by a microphysical scheme (Montmessin et al, 2005).
Smith et al. (2002)
Summer Fall Winter Spring Summer
Water vapor column, in pr. μm
Mars: The LMD/GCM
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Model
Observations
Smith et al. (2002)
Summer Fall Winter Spring Summer
Water vapor column, in pr. μm
Model is forced by:
1) The orbital parameters(Laskar et al., 2002)
1) The atmospheric dust content, inferred from
dust transport simulation
(Newman et al., 2005)
< SAME FORCINGS >
Tharsis tropical mountain glaciers
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Forget et al. (2006)
ε=45°, e=0, τdust=0.2, sources=northern polar cap
Summer north-westerlywinds and precipitation
Northern mid-latitude glaciation
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Clouds(pr. µm)
WV (pr. µm)
Wind (100 m/s)at 5.6 km
ε=35°, e=0.1, Lp=270°, τdust=2.5, sources=TMG
Today Late Am.
Mad
eleine et al. (2
009)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Northern mid-latitude glaciation
(mm/yr)
(mm) (mm)
Mad
eleine et al. (2
009)
Dust feedback: Two planets, same component, same physics, different feedback:
− Mars: positive feedbackdust-atmospheric heating feedback (warms the atmosphere and leads to increased water vapor content).
− Earth: negative feedbackdust-albedo feedback (darkens the ice cover and increases ice melting);
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Discussion (1)
MODIS-NASA, and Malin et al. (2007)
What about the other components of the two climate systems?
− Cryosphere: Ice-thickness feedback (height of the ice sheet changes the geometry of the atmospheric waves);
Ice-albedo feedback (brighter surfaces and change in the net radiation budget);
Ice-thermal inertia feedback (dampens surface temperature variations and reduces ice sublimation);
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Discussion (2)
− Atmospheric dust: Dust lag feedback (on the contrary, a fine layer of dust prevents the underlying ice from sublimating in a low P/T° environment);
− Clouds: Cloud radiative feedback (changes the thermal structure of the atmosphere)
International Conference on Comparative Planetology - 11-15 May 2009 - ESTEC, Noordwijk (NL)
Discussion (3)
Conclusion Ice ages are strongly controlled by ablation on both
planets, but on Mars, precipitation is very sensitive to orbital parameters and atmospheric dust;
GLACIAL EARTH=”COLD”, GLACIAL MARS=”WARM”! Earth model has to be forced by past atmospheric CO2
contents to trigger the Eurasian glaciation; Mars GCM has to be forced by past presumed dust
content to trigger the Northern mid-latitude glaciation;
THRESHOLD-LINKED BEHAVIOR ON BOTH PLANETS! Same components (dust cycle) of the climate system
seem to play a different role in the two glacial cycles:
MARS IS THE ONLY OPPORTUNITY TO STUDY THE SAME COMPONENTS UNDER DIFFERENT CONDITIONS.