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

/

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.