RESPONSE BY THE MARS AND JUPITER UPPER ATMOSPHERES TO EXTERNAL FORCINGS: CONTRASTS FROM TGCM SIMULAT

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RESPONSE BY THE MARS AND JUPITER UPPER
ATMOSPHERES TO EXTERNAL FORCINGS CONTRASTS
FROM TGCM SIMULATIONS
Stephen W. Bougher
University of Michigan (bougher_at_umich.edu)
Hunter Waite and Tariq Majeed
University of Michigan


James R. Murphy
New Mexico State University
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Mars Atmospheric Regions and Processes
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Mars Upper Atmosphere Sampling (Limited
Spatially Temporally)

• Spacecraft Vertical Structures
• Viking 1 1
• Viking 2 1
• Pathfinder 1
• MER A and B
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• Mars Global Surveyor Accelerometer 1600
• Mars Odyssey Accelerometer 600

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Keating et al., 2002
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Odyssey AM Temperatures (100-110 km)
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Global Energy Budgets Power in Watts
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Jupiter Thermosphere-Ionosphere Processes
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Auroral and Equatorial ThermosphericTemperature
Profile Constraints for Jupiter(Waite and
Lummerzheim, 2002)
Galileo ASI Seiff et al. 1998
Auroral discrete and diffuse profiles Grodent
et al 2001
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MTGCM Input Parameters, Fields, and Domain

• Domain 70-300 km 33-levels 5x5
  resolution
• Major Fields and Species T, U, V, W, CO2, CO,
  O, N2
• Minor Species O2, He, Ar, NO, N(4S)
• Ions (PCE) CO2, O2, O, NO, CO, N2 (lt180
  km)
• Time step 150 sec
• Homopause Kzz 1-2x 107 cm2/sec (at 125 km)
• Prescribed Heating efficiencies EUV and FUV
  (22)
• Fast NLTE 15-µm cooling and IR heating
  formulations from M. Valverde 1-D NLTE code
  (Spain)
• Simplified ion-neutral chemistry (Fox et al.,
  1995)
• Empirical Ti and Te from Viking.

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MGCM-MTGCM Simulations Formulation, Parameters
and Inputs

• Separate but coupled NASA Ames MGCM (0-90 km) and
  
• NCAR/Michigan MTGCM (70-300 km) codes, linked
  across an interface at 1.32-microbars on 5x5º
  grid.
• Fields passed upward at interface (T, U, V, Z) on
  2-min time-step intervals. No downward coupling
  enabled.
• MGCM-MTGCM captures upward propagating migrating
  and non-migrating tidal oscillations, as well as
  in-situ driven solar EUV-UV migrating tides in
  the thermosphere.
• Odyssey Ls 270 F10.7 175 t 1.0 (TES-YR2)
• MGS2 Ls 90 F10.7 130 t 0.4
  (TES-YR1)
• (Specified dust distributions. See next
  plots)

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TES Dust Distributions (Ls 90)Year 1
(1999-2000)
LAT
LON
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TES Dust Distributions (Ls 270)Year 2
(2001-2002)
LAT
LON
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MTGCM Odyssey Case (Ls 270)Temperatures at
200 km

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MTGCM Odyssey Case (Ls 270)Temperatures at
110 km

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MTGCM Odyssey Case (Ls 270)Densities at 110 km

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MTGCM Odyssey Case (Ls 270)SLT17
Temperatures versus Latitude

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MTGCM Odyssey Case (Ls 270)SLT3 Temperatures
versus Latitude

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Schematic Of Possible MarsWinter Polar Warming
Process
Subsidence Adiabatic Heating
N
Meridional Flow From Summer H. To Winter H.
Winter
Summer
S
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MTGCM Odyssey Case (Ls 270)SLT 3 Vertical
Velocities versus Latitude

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MTGCM Odyssey Case (Ls 270)SLT 3 Dynamical
Heating versus Latitude

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MTGCM MGS2 Case (Ls 90)SLT 15 Temperatures
versus Latitude

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MTGCM MGS2 Case (Ls 90)SLT 3 Temperatures
versus Latitude

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MTGCM Modeling Summary and Conclusions

• Coupled MGCM (0-90 km) and MTGCM (70-300 km)
  simulations capture the upward propagating
  migrating and non-migrating tides for Ls 90 and
  270 conditions appropriate to MGS2 and Odyssey
  period observations. Mars seasonal atmospheric
  expansion and contraction is also properly
  accommodated.
• MTGCM winter polar temperatures near 100-130 km
  are markedly different between these seasons.
  Strong Northern polar warming features are
  reproduced, in accord with Odyssey observations.
  Weak Southern polar warming features are
  simulated, similar to MGS2 data.
• A stronger inter-hemispheric circulation pattern
  during Northern winter (Ls 270) yields larger
  dynamical heating in the Northern polar
  region. Seasonally varying TES dust
  distributions (and local vertical mixing) are
  likely responsible for these changing winds and
  the resulting polar heat balances at
  thermospheric altitudes.

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JTGCM Input Parameters, Fields, and Domain

• Domain 250-3000 km 39-levels 5x5
  resolution
• Major Fields and Species T, U, V, W, plus H2,
  He, H
• Minor Species CH4 , C2H2 and C2H6
  (Gladstone)
• Ions H2, H3 (PCE), H (dynamical)
• Homopause Kzz 5 x 106 cm2/sec (at
  4.5-microbars)
• Heating 3-component auroral particle (110
  ergs/cm2.s) and Joule heating (30-40) c.f.
  Grodent et al., 2001
• NLTE 3-4-µm cooling from H3 (Miller) and
  hydrocarbon IR cooling (Drossart formulation)
  from CH4 and C2H2
• Simplified ion-neutral chemistry (Waite, Cravens)
• Voyager-1 ion convection pattern (Evitar
  Barbosa 1984)
• VIP4 magnetic field model to map Ui and Vi to
  high lats.

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Profile of JTGCM Auroral Oval Heating(Grodent
et al.,2001)
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JTGCM Ion Convection Pattern(Ui Vi Vectors)
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JTGCM 0.1 µbar Auroral Joule
(40)Temperatures and Winds
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JTGCM 0.1 µbar Auroral Joule (40)Atomic
Hydrogen
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JTGCM ZM Auroral Joule (40)Temperatures
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JTGCM ZM Auroral Joule (40)Zonal Winds
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JTGCM ZM Auroral Joule (40)Meridional Winds
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JTGCM ZM Auroral Joule (40)Adiabatic
Heating (eV/cm3.sec)
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JTGCM ZM Auroral Joule (40)Atomic Hydrogen
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JTGCM Modeling Summary and Conclusions

• Reasonable auroral temperatures and strong
  winds simulated
• with combined particle plus Joule heating
  (30-40) JTGCM
• temperatures at the equator approaching
  Galileo ASI values.
• H3 cooling dynamics dampen impact of Joule
  heating
  
• Strong winds (1.0 km/sec) have a significant
  role in re-
• distributing high latitude heat H-atoms
  toward equator.
• JTGCM dynamical terms dominate equatorial
  heating.
• Scaling required (30-40) to reduce Joule
  heating to bring
• calculated temperatures in line with avail.
  observations.
• Uncertainty in magnetospheric forcing (Ui
  Vi) is likely.
• 40 JTGCM rotations required to achieve steady
  solutions.
• Much different thermal and wind patterns than
  Mars
• (solar EUV/UV versus particle/Joule
  forcing).