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Stochastic Models of Hot Planetary and
Satellite Coronas
The uppermost layers of a planetary
(satellite) atmosphere where the density of neutral particles is infinitely low
are commonly called the exosphere or the planetary (satellite) corona. Since
the atmosphere is not completely bound to the planet (or satellite) by the
planetary gravitational field, such light atoms as hydrogen and helium in the
uppermost atmospheric layers can have velocities that exceed the escape
velocity from this planet and can escape into interplanetary space. This
process is commonly called thermal escape; the thermal escape flux depends on
the temperature of the ambient atmospheric gas, while the flux itself is formed
at heights where the flow of atmospheric gas is virtually collisionless
(Chamberlain and Hunten, 1987). These heights
correspond to the transition region between the underlying collision-dominated
atmospheric layers and the free-molecule exospheric gas. The concept of exobase, the lower boundary of the exosphere, is introduced
as a height at which the atmospheric particle mean free path is equal to the
density scale height (Chamberlain and Hunten, 1987).
For example, in the Earth's upper atmosphere, the exobase
is at a height of about
The current theories of planetary coronas
are based mainly on ground-based and space observations of such exospheric
emission features as the
In recent years, interest in
investigating the role of suprathermal (energetically active) particles in the
physics and chemistry of the upper planetary and satellite atmospheres has
increased (Johnson, 1990; Wayne, 1991; Shizgal and Arkos, 1996; Marov et al., 1997). In particular, the
energetically active particles produced in the upper atmospheric layers have
been shown to play an important role in the chemistry and energetics
of the upper atmosphere or, more specifically,
The following numerical approaches
are mainly used to simulate the nonthermal losses of
planetary atmospheres in practice (see, e.g., Shizgal
and Arkos, 1996; Hunten,
2002):
In general, the stochastic
simulation method consists in constructing a physical-probabilistic analogue of
discrete media with collisional physical-chemical processes and is used to
simulate chemically reacting multi-component gases (dsmc.html).
This approach has been further developed to investigate the formation,
kinetics, and transport of suprathermal particles for the linear and
nonlinear formation of hot planetary and satellite coronas (Shematovich
et al., 1994; Shematovich 2004).
The numerical stochastic models to
study both the local formation and kinetics of suprathermal particles and their
transport in the transition region between the collision-dominated and free
molecular layers of planetary and satellite atmospheres were developed for
different planets and satellites in our Solar System. Moreover, these numerical
models are suitable for investigating the flows of atmospheric gas being weakly
and strongly perturbed by suprathermal particles, i.e., for studying the
formation of hot planetary and satellite coronas in a proper way.
Bird, G.A. Molecular Gas Dynamics,
Chamberlain, J.W. and Hunten, D. Theory of Planetary Atmospheres. An Introduction
to Their Physics and Chemistry,
Ferziger, J. and Kaper,
H. Mathematical Theory of Transport Processes in Gases,
Hunten, D.M. Exospheres and Planetary
Escape, Atmospheres in the Solar System, Mendillo,
M., Nagy, A., and Waite, J.H., Eds.,
Ip, W.-H. On a Hot Oxygen
Johnson, R.E., Energetic Charged
Particle Interactions with Atmospheres and Surfaces,
Johnson, R.E. Surface Boundary Layer
Atmospheres, Atmospheres in the Solar System, Mendillo,
M., Nagy, A., and Waite, J.H., Eds.,
Marov, M.Ya.,
Shematovich, V.I., Bisikalo, D.V., and Gerard, J.-C. Nonequilibrium Processes in the Planetary and Cometary Atmospheres: Theory and Applications,
Nagy, A.F. and Cravens, T.E. Hot
Oxygen Atoms in the Upper Atmospheres of Venus and Mars, Geophys.
Res. Lett., 1988, vol. 15, pp. 433-435.
Shematovich, V.I., Bisikalo, D.V., and Gerard, J.-C. A Kinetic Model of the
Formation of the Hot Oxygen Geocorona. I. Quiet
Geomagnetic Conditions, J. Geophys. Res.,
1994b, vol. 99, pp. 217-226.
Shizgal, B.D. and Arkos,
G.G. Nonthermal Escape of the Atmospheres of Venus,
Earth, and Mars, Rev. Geophys., 1996, vol. 34,
pp. 483-505.
Whipple, E.C., Van Zandt, T.E., and
Love, C.H. Kinetic Theory of Warm Atoms - Non-Maxwellian
Velocity Distributions and Resulting Doppler-Broadened Emission-Line Profiles, J.
Chem. Phys., 1975, vol. 62, pp. 3024-3030.
I. Hot hydrogen coronae:
EARTH:
- hydrogen emissions in the proton and electron
auroras in the Earth's upper atmosphere:
Ly-alpha emission in the proton aurora (abstract).
J. Geophys. Res., 2000, 105, No. A7, 15795-15806.
The role of proton precipitation in the excitation of auroral FUV emissions (abstract).
J. Geophys. Res., 2001, 106, No. A10,
21475-21494.
Observation of the proton aurora with IMAGE FUV imager and simultaneous
ion flux in situ measurements (abstract).
J.
Geophys. Res., 2001, 106, No. A12,
28939 -28948.
ћ
Frey H.
U. , Immel T. J., Mende S.
B., Gerard J.-C., Hubert B., Habraken S., Spann J. , Gladstone G.R.,
Bisikalo D.V., and Shematovich
V.I.
Summary of Quantitative Interpretation of IMAGE
Far Ultraviolet Auroral Data.
Space Sciences Reviews, 2003, 109, 255-283.
ћ
Bisikalo D.V., Shematovich V.I., Gerard J.-C., Meurant
M., Mende S. B., and Frey H. U.
Remote sensing of the proton aurora
characteristics from IMAGE-FUV.
Annales Geophys., 2003,
21, 2165.
ћ
Meurant M., Gerard J.-C., Hubert B., Coumans V., Shematovich V.I., Bisikalo D.V., Evans D.S., Gladstone G.R.,
and Mende S.
B.
Characterization and dynamics of the auroral electron precipitation during substorms
deduced from IMAGE FUV.
J. Geophys. Res., 2003, 108,
No. A6, 1247.
ћ
Chua, D.H., Dymond
K.F., Budzien S.A., McCoy R.P., Gerard J.-C., Coumans V., Bisikalo D.V., and Shematovich V.I.
High resolution FUV observations of proton aurora.
Geophys. Res. Lett.,2003, 30,
No. 18, 1948.
A
Ann. Geophysicae,
2005, 23, 1432-1439.
JUPITER and SATURN:
- hot hydrogen sources, their distribution and auroral hydrogen emissions:
ћ
Bisikalo, D.V.,
Shematovich, V.I., Gerard, J.-C.,
The distribution of hot
hydrogen atoms produced by electron and proton precipitation in the Jovian
aurora (
abstract),
J. Geophys. Res., 1996, 101, 21157.
ћ
Burger M.N., Sittler
E.C., Johnson R.E., Smith H.T., Tucker O.J., and Shematovich V.I.
Understanding
the Escape of Water from Enceladus.
J. Geophys. Res., 112,
A06219, 2007.
The altitude of Saturn's aurora and its
implications for the characteristic energy of precipitated electrons.
Geophys. Res. Lett., 36, L02202, doi:10.1029/2008GL036554,
2009.
EXTRASOLAR PLANETS:
- hot hydrogen sources, their distribution and hydrogen
emissions:
ћ
Shematovich V.I.
Suprathermal
hydrogen produced by the dissociation of molecular hydrogen in the extended
atmosphere
of exoplanet HD 209458b.
Solar System Research, 2010, 44, No. 2, pp. 96-103.
II. Hot nitrogen coronas:
TITAN:
- kinetics and dynamics of hot nitrogen in the
upper atmosphere:
Kinetic modeling of superthermal
nitrogen atoms in the Titan's atmosphere.I. Sources ( abstract).
Solar System Research (English
translation of "Astronomicheskij Vestnik"), 1998, 32, No.5 , 384.
Kinetic modeling of superthermal
nitrogen atoms in the Titan's atmosphere. II. Escape flux due to dissociation
processes (abstract).
Solar System Research (English
translation of "Astonomicheskij Vestnik"), 1999, 33, No.1, 36.
Kinetic modeling of translationally
excited (hot) nitrogen atoms in the Titan's upper atmosphere.
In: Book of abstracts of International
Symposium NANTES98
"The Jovian system after Galileo.
The Saturnian system before Cassini-Huygens",
1998,
Suprathermal nitrogen atoms and molecules in
Titan's corona (preprint).
Adv. Space Res., 2001, 27,
No.11, 1875-1880
Nitrogen loss from Titan.
J. Geophys. Res., 2003, 108, No. E8, 5085.
ћ
Shematovich V.I.
Stochastic
models of hot planetary and satellite coronas:
Suprathermal
nitrogen in Titan's upper atmosphere.
Solar System Research, 2004, 38, No.3, 178-188.
ћ
Smith, H. T., Johnson, R. E., and Shematovich V.I.
Titan's atomic and molecular nitrogen tori.
Geophys. Res. Lett., 31, No. 16, L16804, DOI: 10.1029/2004GL020580, 2004.
ћ
Michael, M., Johnson, R.E., Leblanc, F.,
Liu, M., Luhmann, J.G., and Shematovich
V.I.
Ejection
of nitrogen from Titan's atmosphere by magnetosphric ions and pick-up ions,
Icarus, 2005, 175,
263-267.
III. Hot oxygen coronae:
EARTH:
- formation, kinetics and transport of
"hot" oxygen atoms in the exosphere and thermosphere:
A
kinetic model of the formation of the hot oxygen geocorona.
I. Quiet geomagnetic conditions(abstract).
J. Geophys. Res., 1994,
99, 217.
The importance of new chemical sources for the hot oxygen geocorona (abstract).
Geophys. Res. Lett., 1995, 22,
279.
A
kinetic model of the formation of the hot oxygen geocorona.II.
Influence of O+ ion precipitation (abstract).
J. Geophys. Res., 1995, 100, 3715.
Thermalization of O(1D) atoms in
the thermosphere (abstract).
J. Geophys. Res., 1999, 104, No. A3, 4287-4295.
The
role of hot oxygen on thermospheric OI UV airglow and
density profiles (abstract).
J. Geophys. Res., 1999, 104, No. A8, 17139-17143
Observation of anomalous temperatures in the daytime O(1D)
a possible signiture of nonthermal atoms (abstract).
J. Geophys. Res., 2001, 106,
No. A7, 12753-12764.
An auroral source of
hot oxygen in the geocorona.
Geophys.
Res. Lett., 32,
L02105, doi:10.1029/2004GL021912, 2005.
Energetic oxygen atoms in the
polar geocorona.
J. Geophys. Res., 111, A10301, doi:10.1029/2006JA011823,
2006.
MARS and VENUS:
ћ
Krestyanikova, M.A., and Shematovich, V.I.
Stochastic models of hot planetary and
satellite coronas:
photochemical source of hot oxygen in the upper
atmosphere of Mars.
Solar System Research, 39, No.1,
ћ
Krestyanikova, M.A., and Shematovich, V.I.
Stochastic models of hot planetary and
satellite coronas: a hot oxygen corona of Mars.
Solar System Research, 40, No.5, 384-392, 2006.
ћ
Shematovich, V.I.,
Tsvetkov, G.A., Krestyanikova, M.A., and Marov M. Ya.
Stochastic
models of hot planetary and satellite coronas:
water loss from the atmosphere of Mars.
Solar System Research, 41, No.1, 1-7, 2007.
J. Geophys.
Res., 113, E02011,
doi:10.1029/2007JE002938, 2008.
The Venus ultraviolet oxygen
dayglow and aurora: model comparison with
observations.
Planet. Space Sci., 56, 542-552, 2008.
On the ilusive hot oxygen corona of Venus.
Geophys. Res. Lett., 36, L10204, doi:10.1029/2008GL037575, 2009.
EUROPA:
- near-surface oxygen atmosphere:
Possible mechanism of the
oxygen-bearing atmosphere formation on the Jovian icy satellites ( abstract).
Solar System Research
(English translation of "Astronomicheskij Vestnik"), 2000, 34, No.1, 12.
ћ
Shematovich V.I., and Johnson R.E.
Near-surface oxygen atmosphere at Europa (preprint).
Adv. Space Res., 27,
No.11, 1881, 2001.
ћ
Shematovich, V.I., Johnson, R.E., Cooper, J. F., and Wong, M.C.
Surface-bounded atmosphere
of Europa,
Icarus, 173, 480-498, 2005.
ћ
Shematovich V.I.
Stochastic models of hot
planetary and satellite coronas: Atomic oxygen in Europa's
corona.
Solar
System Research, 40, No.3, 175-190,
2006.