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MCD upgrades and developments Progress Report July 11, 2012

MCD upgrades and developments Progress Report July 11, 2012. Ehouarn Millour , François Forget, Arnaud Colaitis , Luca Montabone , Aymeric Spiga. Status of MCD v5 development.

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MCD upgrades and developments Progress Report July 11, 2012

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  1. MCD upgrades and developmentsProgress Report July 11, 2012 EhouarnMillour, François Forget, Arnaud Colaitis, Luca Montabone, Aymeric Spiga

  2. Status of MCD v5 development • After some work on tuning the CO2 cycle (and H2O cycle), a first series of full MCD runs (with photochemistry, thermosphere, etc.) was conducted, with many dust scenarios: MY24, MY25, MY26, MY27, MY28, MY29, MY30, cold, warm. • These outputs have been combined in a “MCDv5.0 alpha” with mean, cold and warm scenarios for testing (dust storm separately tested, see Luca’s presentation). • We will need to perform a new set of simulations (1 simulation is ~2 weeks CPU on our cluster) to generate datafiles to build an “MCDv5.0 beta” suitable for preliminary distribution.

  3. Design of MCD v5 dust scenarios • The cold scenario: Very low amount of airborne dust. Dust opacity at a given season and location is taken as the minimum over the 7 Martian years MY24-MY30 dust scenarios, moreover decreased by 30%.

  4. Design of MCD v5 dust scenarios • The warm scenario: Very high amount of airborne dust (but not a planet encircling dust storm event). Dust opacity at given season and location is taken as the maximum over the 7 Martian years (excluding the global dust storm periods during MY25 and MY28), moreover increased by 30%.

  5. Design of MCD v5 dust scenarios • Combining the outputs of runs from all 5 “non-global dust storm” years (MY 24, 26, 27, 29, 30), we generate the mean year climatology. • In addition, the variability encompassed in all these simulations is included in the MCDv5 improved large-scale perturbation scheme.

  6. The Mean Year Dust Scenario • The “mean dust scenario” is simply compiled as an ensemble average of the five separate MY runs.

  7. Large Scale Perturbation Model • Which variables?: profiles (over all 50 vertical levels) on a reduced lonxlat grid (32x24, i.e. 11.25°x7.5° ; much better than the 16x12 grid of MCDv4.3!) for temperature, horizontal winds and surface pressure, are saved (1/day) during GCM runs. • How is the information stored?: Usinglonxlatxalt EOF (Empirical Orthogonal Functions) decomposition AVE: average value NORM: Normalization const. PC: Principal Component N: Number of EOFs retained (32x24x(3x50+1)=115968 elements for each EOFi and 669 elements for each PCi), which are ordered (by design) from “most” to “least” significant. => But how many EOFs should be retained?

  8. The New Large Scale Perturbation Model • A technical issue: How many EOFs should be retained to yield a good enough variability? • Cross-checking with the simulations gives the answer: • Example: Values of surface pressure near VL2 site from a GCM simulation

  9. The New Large Scale Perturbation Model • A technical issue: How many EOFs should be retained to yield a good enough variability? • Cross-checking with the simulations gives the answer: • Example: Values of surface pressure near VL2 site from a GCM simulation, and reconstructed, using 50 EOFs

  10. The New Large Scale Perturbation Model • A technical issue: How many EOFs should be retained to yield a good enough variability? • Cross-checking with the simulations gives the answer: • Example: Values of surface pressure near VL2 site from a GCM simulation, and reconstructed, using 100 EOFs

  11. The New Large Scale Perturbation Model • A technical issue: How many EOFs should be retained to yield a good enough variability? • Cross-checking with the simulations gives the answer: • Example: Values of surface pressure near VL2 site from a GCM simulation, and reconstructed, using 200 EOFs

  12. The New Large Scale Perturbation Model • A technical issue: How many EOFs should be retained to yield a good enough variability? • Cross-checking with the simulations gives the answer: • Example: Values of the “monthly” RMS surface pressure near VL2 site from a GCM simulation, and reconstructed, using 50, 100 and 200 EOFs. • Keeping 200 EOFs is best compromise.

  13. The New Large Scale Perturbation Model From the PCs are computed, using a 30 day running mean, “smoothed” Principal Components PCsmooth. Using just PCsmooth enables reconstructing the mean signal. • Example: reconstruction of surface pressure near VL2 site, using PCs or PCsmooth.

  14. The Large Scale Perturbation Model • General Idea: Build PCnew from PC and PCsmooth to evaluate the perturbation but at another instant: • Where ‘othertime’ is randomly determined and within a 30 sol window of ‘time’. This way we conserve the spatio-temporal coherence of transient phenomena. • The perturbed series is then always simply rebuilt as: • Moreover, EOFs and PCs from all the computed Mars Years scenarios can be used as seeds to inject realistic variability in the “mean” scenario and thus represent the full interannual variability of the Martian atmosphere.

  15. The New Large Scale Perturbation Model • Illustrative example: • MY24 scenariomean scenario • with MY24 EOFswith all MY EOFs • Technically the user doesn’t choose from which MY the EOFs come from (this is done randomly, using the seed used to generate the perturbations).

  16. Improving the call_mcd Software • The « thermals model » related variables have been included: • Extvar(55) : Surface Stress (kg/m/s2) • Extvar(56) : Sensible Heat Flux (W/m2) • Extvar(57) : Planetary Boundary Layer Height (m) • Extvar(58) : Free Convection Velocity (m/s) • Extvar(59) : Vertical Velocity Variance at given alt. (m2/s2) • Extvar(60) : Vertical Eddy Heat Flux at given alt. (m/s/K) • The possibility to choose which extra variables are to be computed can now be set via the extvarkeys(100) array: • Extvar(i) will be computed if extvarkeys(i)=1 and won’t be computed if extvarkeys(i)=0 • Note that the extvarkeys(100) array replaces the extvarkey (scalar) in the argument list of the call_mcd routine.

  17. To do list • Runall the GCM simulations (including ionosphere, better tuned CO2 and H2O cycle, fixed or realistics EUV inputs, etc.) to have all the necessary datasets to build MCDv5.0 beta. • Test, test and test again the new MCD software. • Implement specific versions of the MCDv5 software with the added features (ie: specific dust scenarios) for TAS-I. • Conduct validation campaign of MCDv5.0 versus available measurements (TES, MCS, Radio occultations, etc.)

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