1. MGCM & group: AFCB, Sept 2007 @ SJSU 1 The Mars General Circulation Modeling Group Alison F.C. Bridger SJSU

2. MGCM & group: AFCB, Sept 2007 @ SJSU 2 The Mars General Circulation Modeling Group Our fearless leader is Dr. Bob Haberle of NASA- Ames; SJSU graduate. URL: http://www-mgcm.arc.nasa.gov/MGCM.htmlhttp://www-mgcm.arc.nasa.gov/MGCM.html

3. MGCM & group: AFCB, Sept 2007 @ SJSU 3 The NASA-Ames MGCM Origin of the model Derived originally from the UCLA model (Mintz, Arakawa) Adapted to Mars originally by Leovy Adaptations include… Planetary constants (easy) Radiation (not so easy!) Other (some still being determined)

4. MGCM & group: AFCB, Sept 2007 @ SJSU 4 The NASA-Ames MGCM Model details Finite difference (hydrostatic) Roughly 0-80 km Physics in the model Shortwave heating – absorption by CO 2 and dust Solar heating of the ground Sensible heat flux back up to the atmosphere Heat conduction into/out of the regolith (soil model) Melting of CO 2 ice; effects of sub-surface ice

5. MGCM & group: AFCB, Sept 2007 @ SJSU 5 The NASA-Ames MGCM Physics in the model ctd. Longwave heating/cooling (CO 2 ) Dust in the atmosphere User-specified? Internally determined? Observed spatial versus depth distributions Dust particle properties (mineral, size, shape) Radiative effects

6. MGCM & group: AFCB, Sept 2007 @ SJSU 6 The NASA-Ames MGCM Physics in the model ctd. Water (vapor, ice) in the atmosphere Water (ice) clouds & fog CO 2 ice clouds CO 2 deposition onto/sublimation from the ice caps & the CO 2 annual cycle

7. MGCM & group: AFCB, Sept 2007 @ SJSU 7 The NASA-Ames MGCM Ongoing developments at NASA-Ames (led by Bob Haberle) New dynamical “core” added in the last two years (GFDL) allows multiple tracers, including water and dust Soon to be replaced with a new core/grid structure

8. MGCM & group: AFCB, Sept 2007 @ SJSU 8 The NASA-Ames MGCM Ongoing developments New radiation code More powerful and sophisticated More “expensive”! Allows radiative effects of water ice, CO2 ice, & dust to be incorporated and explored

9. MGCM & group: AFCB, Sept 2007 @ SJSU 9 The NASA-Ames MGCM Ongoing developments Ground ice…soil model Clouds (CO2, water) Aerosol/dust

10. MGCM & group: AFCB, Sept 2007 @ SJSU 10 Applications Mission support Planning for conditions (densities) in the upper atmosphere during aerobraking activities Planning for conditions during descent Planning for conditions on the surface

11. MGCM & group: AFCB, Sept 2007 @ SJSU 11 Applications Interpretation of observations E.g., MGS densities (Kelvin waves) Streaks on the surface (wind scouring, prevailing wind directions) Baroclinic wave activity! Cloud observations!

12. MGCM & group: AFCB, Sept 2007 @ SJSU 12 Applications “Paleoclimate” A “warm, wet” early Mars, or not? Present-day climate Climate change? Viking versus MGS “swiss cheese” observations

13. MGCM & group: AFCB, Sept 2007 @ SJSU 13 Some of my recent work… Simulations of the “MGS year 2” global dust storm Goal = successful self-contained simulation of the storm Now … still specifying dust distributions & history Simulated temperatures compare well with MGS-TES observations Use the model to suggest ways the storm might have expanded

14. MGCM & group: AFCB, Sept 2007 @ SJSU 14 Results…

15. MGCM & group: AFCB, Sept 2007 @ SJSU 15 Results…