1. MODERN CLIMATE AND HYDROLOGICAL CYCLE OF MARS. A.V.Rodin, A.A.Fedorova, N.A.Evdokimova, A.V.Burlakov, O.I.Korablev 1Moscow Institute of Physics and Technology, Russia; Space Research Institute, Russia. Contact: Alexander.Rodin@phystech.edu

2. Seasonal and latitudinal distribution of water vapor Viking 1,2 MAWD TES – 20-40 microns 1.38 μm MY 27 SPICAM IR Smith 2002-2008 Fedorova et al. 2006Jakosky, Farmer 1984

3. Jakosky et al.1984-1995: Titov, Houben Regolith matters Clancy et al., 1996: Circulation affected by Richardson, Wilson, 2003orbit excentricity & Montmessin et al., 2004hemispheircal asymmetry cloud microphysics matters TES, PFS, OMEGA, SPICAM, MCS: search for zonal, seasonal and interannual variations

4. Mars Atmosphere General Circulation Model FMS dynamical core Aerosol –consistent radiation H 2 O cloud microphysics 1  1.5 , k z =28 Ls = 270  z=5 km

5. GCM illustration of Clancy effect: aphelion-perihelion asymmetry

6. perihelion aphelion Clancy et al., 1996, Montmessin et al, 2002

7. Seasonal Mars water cycle: GCM results

8. Water vapor column distributions on Mars imply significant zonal variations: Viking/MAWD (Fedorova et al., 2004, Pankine et al.,2009) Ls = 20  Ls = 330  Ls = 150  Ls = 90  MGCM simulations

9. Water vapor annual average: atmosphere-surface interactions Water vapor column, pr.  m Exposure (days) of frost layer exceeding 100  m Mitrofanov et al., 2002 Antipodal maxima of bound water content

10. Annual average (contd.) H 2 O molecules number density provided T > 220 K Cold trap: t otal time when  T>30 K and T > 200 K, days Basilevsky et al., 2006, Nelli et al., 2006

11. Soil hydration: - significant latitudinal variations - no evident connection to the seasonal water cycle Evdokimova et al., 2010

12. MGS/TES (Pankine et al.,2009)

13. MEX/SPICAM: Spatial distribution of water vapor summer in north hemisphere L s 95-120: 59 orbits from 72 orbits are presented Fedorova et al, 2009

14. 00 180  10 20 30 40 50 60 MGCM instant water vapor column: North hemisphere [pr.  m] 00 180  0 100 200 Ls = 92  00 180  0 100 200 Ls = 113  Ls = 142 

15. L s ~93  -97  OMEGA: Modes 2 and 3 in NPC sublimation marked by 1.25  m water ice band depth MGCM water column, pr µm L s ~113  -115  L s ~127  -136  L s ~94  L s ~114  L s ~132 

16. The location of maximal wind stress at the NPC coincides with spots of enhanced ice aging 0505 Near-surface wind according to MGCM (m/s) Ls = 92  Ls = 113  Ls = 137  + + + + + (!) NPC sublimation rate depends on dynamics of the ambient atmosphere, not just heating and relative humidity

17. Ls = 145  event: switching from mesoscale to global perturbation Ls = 92  Ls = 137  Ls = 147  Zonal flow meridional shear Meridional V-component Emerging circumpolar vortex Wave-3 pattern -55-1010 -5 5 Decaying circumpolar vortex

18. Polar vortex barotropic instability: laboratory studies (Barbosa et al., 2010)

19. Mode 3 in the residual seasonal water ice deposits (left) and MGCM moisture (right) MEX/OMEGA 1.5  m index Rodin et al., 2010 MGCM

20. South hemisphere Ls = 225  event: implications to dust cycle Ls = 220  Ls = 227  Near-surface dust mixing ratio (ppm) Wave-3 pattern 0 50 Ls = 233  Wave-2 pattern Wave-4 pattern 0 50 Season of the strongest transient in the South hemisphere coincides with the window of dust storm initiation

21. Conclusions The nature of current Mars water cycle is understood; GCMs are able to reproduce observables The role of polar caps, regolith, and clouds needs further quantitative assessment Water cycle demonstrates a major role of low-wavenumber eddy transport in the Martian atmopsheric circulation