Assessment of possible
Mars landing site forMars-EDL
Ko-ichiro Sugiyama
Japanese-French model studiesof planetary atmospheres
2015/05/13

Introduction• A Mars surface exploration program is discussed
by space engineering and planetary science
communities in Japan (MARS-EDL).
• Evaluation of plausible range of meteorologicalconditions at landing site is required.
– To support designing the landing module andobservation instruments and ensure safety
mission operation• We join MARS-EDL working group, because
it is a good chance to improve our models andto get experience of performing assessment forexploration program.

Models• Our research group now progress to assess the Mars surface
environment by using following numerical models results.
– General Circulation Model (GCM):
DCPAM (developed by GFD_Dennou_Club)– Cloud Resolving models (CRM)
CReSS-Mars (developed by Nagoya U.)
deepconv (developed by GFD_Dennou_Club)– a Large Eddy Simulation (LES) model
SCALE-LES (developed by RIKEN AICS)

Models: summary of our status• DCPAM [GCM] (developed by GFD_Dennou_Club)– Proper calibration for assessment of Mars surface environment isestablished.
– The calibrated data are used in Mars-EDL working group.

• CReSS-Mars [CRM] (developed by Nagoya U., Japan)– As a preparation, a lot of numerical experiments are performed inorder to examine performance of CReSS-Mars• deepconv [CRM] (developed by GFD_Dennou_Club)– Topography is not considered.
– We are planning to perform comparative experiments between
CReSS-Mars and deepconv with idealistic condition.

• SCALE-LES [LES] (developed by RIKEN)– Some idealistic experiments are performed (see presentation ofDr. Nishizawa)

Assessment of Mars surface environment
using Planetary General circulation
model, DCPAM
M. Odaka, K. Sugiyama, Y. O. Takahashi,
S. Nishizawa, Y.-Y. Hayashi, G. Hashimoto
We show:• Comparison between simulation results of DCPAM andobservations• Proper calibration for assessment of Mars surface environmentby using DCPAM data.
• Contribution to MARS-EDL

Model and Simulation setup• DCPAM is a planetary atmospheric general circulation model
developed by GFD Dennou Club (Takahashi et al. 2012).
– A spectral GCM designed
by using primitive equation system.
– Physical processes are included• subgrid scale turbulence• CO2 condensation/sublimation• atmospheric and dust radiation• surface process– The topography, surface albedo
and thermal inertia in the model
are based on observation results
obtained by Mars Global Surveyor(MGS).
Figure: Schematic figure of DCPAM	Model and Simulation setup• Simulation setup is as follows.
– Resolution• The horizontal truncation wave number is 31( dx ~ 200 km).
• The number of vertical layer is 36 and the height oflowest level is about 3 m.
– Dust opacity• MGS senario [default]• constant opacity (τ = 0, 1, 3, 5)– Numerical integration is performed for 7 Mars years withisothermal no motion initial condition.
• The data of last two years are used for analysis.

Comparison results:
Surface atmospheric temperature• Diurnal variation of atmospheric temperature at 1.5 m heightobserved by MPF is well reproduced.
– Logarithmic wind and temperature profiles under neutral
stratification are assumed.
– interpolating with ground temperature and atmospherictemperature at 2nd model level (about 12.5 m height).
（K）	
+: MPF	+: T at 0 m[surface]+: T at 12.5 m[2nd grid]+: T at 1.5m	
[estimate]	
Figure: Diurnal variation of ground and atmospheric temperatures	Comparison results:Surface atmospheric pressure• The seasonal variation of surface pressure observed by Viking
Lander 1 (VL1) is almost represented by the model with somecalibrations– a height difference between the model grid and actual
landing site by using a scale height at 10th model level– uncertainty of global mean atmospheric mass by
subtracting 60 Pa.
after calibration 	P	  =	  Ps	  exp(	  Δz/H	  )	+: VL1+: model	

P	  =	  Ps	  exp(	  Δz/H	  )	  -­‐	  60	+: VL1+: model	

Figure: Seasonal variation of surface pressure at Viking Lander 1 site: 	Contribution to MARS-EDL• Based of the calibration, assessment of surface environment
at proposed landing sites is published on a Web.
• This data is used in Mars-EDL working group.

Assessment of Mars surface environment
using Cloud Resolving Model, CReSS-Mars

K. Sugiyama, M. Odaka, K. Nakajima, Y. O. Takahas1hi,
S. Nishizawa, N. Otobe, G. Hashimoto,K. Hasegawa, A. Sakakibara, K. Tsuboki••

2D experiment with idealized boundary condition• We examine whether the obtained diurnal change oftemperature is consistent with the data obtained by
DCPAM-1D and NASA's Mars lander, Spirit.
3D experiment using DCPAM data
• We examine whether CReSS-Mars successfully run when
considering very steep slope and using DCPAM data
as initial and boundary conditions.

Model description•

We apply CReSS to Martian atmosphere since April 2013
• CReSS is a well-developed cloud resolving model used in studiesof terrestrial mesoscale phenomena (Tsuboki and Sakakibara, 2002).

•CReSS-Mars is based on CReSS ver.3.4.
– Dynamical core: quasi-compressible system (Klemp andWilhelmson, 1978).
– Sub-grid scale turbulence: Deardorff (1980).
• also used by Spiga et al. (2010)– Radiation: Takahashi et al. (2003, 2006)• CO2 gas and dust are considered.
• The source code of DCPAM is installed– Surface momentum and heat fluxes: Louis et al. (1982).
– The surface and ground temperature are calculated byusing one-dimensional thermal diffusion equation.

2D experiment with idealized boundary condition•••••••••

Location: Spirit landing site (14.6 S, 175.5 E)
Dust opacity: τ = 0.3
Opportunity	
No topography
Spirit	Cyclic condition (Horizontal)
Grid size: 250 x 200 (2-dimensional)
Resolution: Δx = 200 m, Δz (mean) = 200 m, Δz (min) = 2 m
Initial temperature profile: calculated by DCPAM-1D.
Integral time: 6 days.
In order check variability, other mixing length of unstable layer
included turbulence parameterization is also used.
This follows Prandtlʼs– default : l = l0(z)(Deardorff, 1980)
mixing theory near the• suggested by Spiga et al. (2010)• where l0 = (Δx Δy Δz)1/3, κ = 0.4

surface. Its origin is aforecast model of Japan
Meteorological Agency– test case: 1/l = 1 / κz + 1/ l0(z) (CReSS original)zoom	DCPAM-1D

CReSS-Mars	S-Ma– Same source code of radiativetransfer equation is used.

CReS

DCPA

M-1D	

• The results are almost
consistent with those obtainedby 1D convective-radiativemodel (DCPAM-1D).

rs	

Compare to DCPAM-1D

Compare to Spirit observation• At daytime ( LT=10:05, 12:55, 16:30 ), temperature lapse rate
near the surface is roughly consistent with the observation.

Spirit	CReSS	

Dependency on the mixing length• The mixing length of
the turbulence process
is one of the major
problem, which effects
temperature profilenear the surface.

Parameter: the mixing length of unstable layer.
• default : l = l0 (z)(Deardorff, 1980)• test case : 1/l = 1 / κz + 1/ l0 (z) (CReSS original)– Surface temperaturesof both cases arealmost the same.

CReSS-Mars(default case)	

CReSS-Mars(default case)	

CReSS-Mars(test case)	

CReSS-Mars(test case)	

Spirit (obs.)	

Spirit (obs.)	

Zoom	

3D experiment using DCPAM data
• Location:
Opportunity landing site (1.9S, 2.5W)• Grid size: 750 x 500 x 64
Opportunity	
• Resolution:Spirit	
Δx = Δy = 0.012° (~700 m),
Δz (mean) = 500m, Δz (min) = 20 m
• Dust opacity: τ = 0.3• Season: Ls = 0 (the vernal equinox day)• Simulation data of DCPAM is used as initial and boundary
conditions in order to consider the large-scale effect.
• Topography are considered• Integral time: 2 days (177600 sec)Results• The temporal variation of convective activity is successfullycalculated.
– Small-scale circulation in daytime is similar to that obtained
LES calculation.
Vertical velocity (above ~10m)	

Vertical velocity (above ~430m)	

Topography	Other sites …

~ 150 km	

• However, CReSS-Mars can not run when
considering very steep slope such apossible landing site of MARS-EDL.
• One of the reasons may be gridinterval of DCPAM and CReSS-Mars– DCPAM: dx ~ 200 km– CReSS-Mars: dx ~ 500 – 1000 m(domain size : L ~300 - 500 km)• We will try to change nesting
DCPAM (dx ~ 200 km)=> CReSS-Mars (dx ~ 10 km)=> CReSS-Mars (dx < 1 km)-5 km	
dz ~ 9 km	

• At Opportunity landing site, CReSS-Mars
successfully run using DCPAM data as
initial and boundary conditions.

Melas Chasma	６km	Summary• Some numerical experiments are performed in order toexamine performance of CReSS-Mars• 2D experiment with idealized boundary condition– The obtained diurnal change of temperature is consistent withthe data obtained by DCPAM-1D and NASA's Mars lander, Spirit.
– The mixing length of the turbulence process is one of the major
problem, which effects temperature profile near the surface.

• 3D experiment using DCPAM data
– In some cases, CReSS-Mars successfully run using DCPAM data as
initial and boundary conditions.
– We will try to change nesting in order to perform simulation withvery steep slope such a possible landing site of MARS-EDL.