Post on 24-Dec-2015
Atmospheric Environment Characterization in Support of the ESA ExoMars MissionIntercomparison LMD – SwRI models
T. Bertrand, S. Rafkin, F. Forget, A. Spiga, E. Millour
Project statusNovember – start
• Phase 1 : LMD built 1D version for SWRI for radiative transfer synchronisation
• LMD sent reference profiles
December • First SWRI profiles received • Solving reference time issues (bug, LTST vs LMST, UT
versus LT) • Investigation on surface temperature disagreement
Problem of shortwave flow LMD found a bug in SWRI latitude
• Tuning the right options in both model (philosophy: LMD fit SWRI)
Project statusJanuary
• Comparison of 1D reference profiles with dust opacities at 0.2, 1, 5
• LMD tries to match SWRI dust radiative effects and radiative models by tuning:
1. Dust opacity 2. Dust visible single scaterring albedo
("brightness of the dust") 3. Dust thermal infrared opacity vs visible
opacity
Radiative transfer setting – 1D configuration
Note : the radiative transfer model used by SWRI (NASA Ames) is known to underestimate dust heating rates. They partly compensate that by using "dark" dust radiative properties.
1D Run parameters – 6 cases:
Comparison LMD – SwRI without tunning
Comparison LMD – SwRI with tunning of dust properties
Comparison LMD – SwRI without tunningSurface flux SW
Comparison LMD – SwRI without tunningSurface flux LW
Comparison LMD – SwRI without tunningSurface temperature
Comparison LMD – SwRI without tunningTemperature profiles
Comparison LMD – SwRI without tunningTemperature profiles
Comparison LMD – SwRI without tunningTemperature profiles
Comparison LMD – SwRI without tunningTemperature profiles
Comparison LMD – SwRI without tunningTemperature profiles
Comparison LMD – SwRI without tunningTemperature profiles
Sensibility to dust opacity Temperature profiles
Sensibility to dust opacity Temperature profiles
Sensibility to dust opacity Temperature profiles
Sensibility to dust brightnessTemperature profiles
Sensibility to dust brightnessTemperature profiles
Sensibility to dust brightnessTemperature profiles
Sensibility to ratio dust thermal IR vs VIS opacityTemperature profiles
Fitting C1 case with the three parametersTemperature profiles
BEST FITS – Case A1Temperature profiles
BEST FITS – Case A1Surface temperature
BEST FITS – Case B1Temperature profiles
BEST FITS – Case B1Surface temperature
BEST FITS – Case C1Temperature profiles
BEST FITS – Case C1Surface temperature
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Many plots available on:
http://www.lmd.jussieu.fr/~tblmd/Intercomparison/1D_plots
Conclusion
• 1D comparisons are globally ok
• Turbulent diffusion scheme in the boundary layer: fundamental model differences that should be kept in the intercomparison ?
• Green light has been given to SwRI to start running GCM, Mesoscale and LES models.