Seasonal water cycle of Mars observed by OMEGA and PFS

1
Seasonal water cycle of Mars observed by OMEGA
and PFS
Water Cycle Workshop 21 Apr 08

• L. Maltagliati(1), M. Tschimmel(1), D.V.
  Titov(1,2),
• T. Encrenaz(3), R. Melchiorri(3), T. Fouchet(3),
• N.I. Ignatiev(2,5), J.-P. Bibring(4), V.
  Formisano(5)

• Max-Planck Institute for Solar System Research,
  Katlenburg-Lindau (Germany)
• Space Research Institute of Russian Academy of
  Science, Moskow (Russia)
• (3) LESIA, Observatoire de Paris, Meudon (France)
• (4) IAS/CNRS, Univ. Paris-Sud, Orsay (France)
• (5) Istituto di Fisica dello Spazio
  Interplanetario (INAF-IFSI), Roma (Italy)

2
Seasonal water cycle of Mars observed by OMEGA
(and PFS)
Water Cycle Workshop 21 Apr 08

• L. Maltagliati(1), M. Tschimmel(1), D.V.
  Titov(1,2),
• T. Encrenaz(3), R. Melchiorri(3), T. Fouchet(3),
• N.I. Ignatiev(2,5), J.-P. Bibring(4), V.
  Formisano(5)

• Max-Planck Institute for Solar System Research,
  Katlenburg-Lindau (Germany)
• Space Research Institute of Russian Academy of
  Science, Moskow (Russia)
• (3) LESIA, Observatoire de Paris, Meudon (France)
• (4) IAS/CNRS, Univ. Paris-Sud, Orsay (France)
• (5) Istituto di Fisica dello Spazio
  Interplanetario (INAF-IFSI), Roma (Italy)

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Water vapor retrieval method
Ps 6.05 mbar fh2o 200 ppm
only one free parameter mixing ratio below
saturation
Synthetic spectrum
Measured spectrum
OMEGA data

• line-by-line algorithm
• spectral database HITRAN04
• climate data from EMCD
• well-mixed vertical profile
• saturation cut-off
• no dust correction

• corrected for solar spectrum
• calibrated to the continuum

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Water vapor retrieval method

• OMEGA data

corrected for the solar spectrum calibrated to
the continuum
Ps 6.05 mbar fh2o 200 ppm
Measured spectrum
Synthetic spectrum
fh2o 81.875 ppm s 0.45
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Retrieval strategies

• global monitoring
• all orbits
• no mapping

• regional analysis
• selected areas only
• hi-res mapping
• first timers!

500000 spectra / orbit
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Seasonal behaviour
OMEGA
color scale 0 60 pr. µm.
MGS/TES
corrected
(courtesy of M. Smith)
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Comparison with MEx datasets
OMEGA
PFS-SW
(Tschimmel et al. 2008)
40
SPICAM
PFS-LW
(Fouchet et al. 2007)
(Fedorova et al. 2006)
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A look at the second MEx year
MY 28 - N spring
OMEGA
edge of the seasonal cap
PFS
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Longitudinal distribution
?
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Diurnal fluctuations?
TES OMEGA (pr.µm)
local hour
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Vertical dependence - saturation level
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Conclusions
All aspects of the annual water cycle are covered

• seasonal behavior well in agreement with
  previous results

some differences in structure details (e.g.
shape of summer maxima, less intense transport
during N summer)
comparison with datasets (MEx)
generally good quantitative agreement PFS-LW lt
SPICAM OMEGA lt PFS-SW
TES!
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Conclusions

• longitudinal behavior also in fair agreement
• diurnal variability minor
• vertical distribution saturation level 10 50
  km

two maxima (Tharsis, Arabia) one strong minimum
(in between) polar inhomogeneities minor
seasonal variations
annual trend (aphelion perihelion) agreement
with TES
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Thank you!