MODERN CLIMATE AND HYDROLOGICAL CYCLE OF MARS. A.V.Rodin, A.A.Fedorova, N.A.Evdokimova,...
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Transcript of MODERN CLIMATE AND HYDROLOGICAL CYCLE OF MARS. A.V.Rodin, A.A.Fedorova, N.A.Evdokimova,...
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: [email protected]
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. 2006 Jakosky, Farmer 1984
Jakosky et al.1984-1995:
Titov, Houben Regolith matters
Clancy et al., 1996: Circulation affected by
Richardson, Wilson, 2003 orbit excentricity &
Montmessin et al., 2004 hemispheircal asymmetry
cloud microphysics matters
TES, PFS, OMEGA, SPICAM, MCS: search for zonal, seasonal and interannual variations
Mars Atmosphere General Circulation Model
•FMS dynamical core•Aerosol –consistent radiation•H2O cloud microphysics•11.5, kz=28
Ls = 270 z=5 km
GCM illustration of Clancy effect: aphelion-perihelion asymmetry
perihelion aphelion
Clancy et al., 1996, Montmessin et al, 2002
50 100 150 200 250 300 350-90
-60
-30
0
30
60
90
Water vapor, pr. m
Solar areocentric longitude
L
atitu
de
5
5
510
10
10
10
15
15
15
15
15
15
15
20
20
20
202
0
2020
25
25
25
25
3030
30
35
35
4045
50 60 65
Seasonal Mars water cycle: GCM results
Water vapor column distributions on Mars
imply significant zonal variations:Viking/MAWD (Fedorova et al., 2004, Pankine et al.,2009)
Ls = 20
Ls = 330Ls = 150
Ls = 90
MGCM simulations
Water vapor annual average:atmosphere-surface interactions
Water vapor column, pr. mExposure (days) of frost layer
exceeding 100 m
Mitrofanov et al., 2002
Antipodal maxima of bound water content
Annual average (contd.)H2O molecules number densityprovided T > 220 K
Cold trap: total time when T>30 Kand T > 200 K, days
Basilevsky et al., 2006, Nelli et al., 2006
Soil hydration: - significant latitudinal variations - no evident connection to the seasonal water cycle
Evdokimova et al., 2010
MGS/TES (Pankine et al.,2009)
MEX/SPICAM: Spatial distribution of water vapor summer in north hemisphere
Ls 95-120: 59 orbits from 72 orbits are presented
Fedorova et al, 2009
0
180
10
20
30
40
50
60
MGCM instant water vapor column: North hemisphere [pr. m]
0
180
0
100
200
Ls = 92
0
180
0
100
200
Ls = 113 Ls = 142
Ls~93-97
OMEGA: Modes 2 and 3 in NPC sublimation marked by 1.25 m water ice band depth
MGCM water column, pr µm
Ls~113-115 Ls~127-136
Ls~94 Ls~114 Ls ~132
The location of maximal wind stress at the NPC coincides with spots of enhanced ice aging
0 5
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
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
-5 5 -10 10-5 5
Decaying circumpolar vortex
Polar vortex barotropic instability: laboratory studies (Barbosa et al., 2010)
Mode 3 in the residual seasonal water ice deposits (left) and MGCM moisture (right)
MEX/OMEGA 1.5 m indexRodin et al., 2010 MGCM
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 0 50
Season of the strongest transient in the South hemisphere coincides with thewindow of dust storm initiation
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