ISSI
International Team 89
SCIENTIFIC RATIONALE AND TIMELINESS OF THE PROJECT
PROJECT
The
aim of the study is to define
how
wave field measurements on board magnetospheric satellites may be used
to trace
Wave Particle Interactions (WPI) involved in magnetosphere / ionosphere
/
atmosphere couplings. The emphasis is put on processes taking place in
the
plasmasphere and in the medium and low latitude ionosphere (L£7).
The context is the preparation of the CNES micro
satellite
project TARANIS devoted to the identification of several types of
magnetosphere
/ ionosphere / atmosphere couplings. Its phase A started in January
2005 and
has to be completed by June 2006.
At
the origin of the study is the need to
establish the feasibility of observing runaway electrons associated
with
Transient Luminous Events (TLEs) generated below 100 km altitude by
other
means than direct measurement of the energetic particles. In particular
remote
detection through wave field measurements may be more feasible and
provide a
more unique signature within the ionospheric plasma environment than
other
remote diagnostics. As similar questions may be raised for other
ionospheric
and magnetospheric processes, the study has been extended to the use of
wave
field measurements to trace accelerated and precipitated particles, or
more
generally to trace wave particle Interactions (WPI), taking place
within the
equatorial regions as well as at low altitudes. It is mainly focused on
medium
and low latitudes. Higher latitudes have been studied in the past and
involved
other phenomena. In the context of a satellite mission one concentrates
on the
low frequencies (f £ 30 MHz) which are submitted to ionospheric
filtering when monitored from the ground. One his in the situation of a
space
radioastronomer who is looking for long wave length radio waves and
pulses. The
main difference is that one may use electromagnetic and locally
produced
electrostatic waves.
An example
of the
studies one would
like to undertake is the examination of resonance interactions as the
source of
a direct coupling between the magnetosphere and the atmosphere. Several
types
of resonance interactions take place in the equatorial region of the
plasmasphere. They contribute to the magnetosphere / atmosphere
coupling via
the precipitation of energetic electrons from the radiation belts. As
shown by
several authors (Callis et al., 1996, 1998; Siskind et al., 2000;
Callis, L.B.,
2001; Callis et al., 2001, 2002), energetic electrons precipitated from
the
outer radiation belt (L > 5) are at the origin of NOx formed at high
altitudes
then transported from the upper atmosphere to the stratosphere during
polar
winter. After the observation by the SAOZ balloon borne instrument of
unexplained enhancements in the concentration of NOx above the South
Atlantic
Anomaly, on the Eastward side (Huret et al., 2002), i.e. on the side
where
intense fluxes of precipitated energetic electrons are observed, one
may wonder
if middle and low latitude energetic electrons could also contribute to
the
formation of NOx, and so to the coupling between the ionised and
neutral parts
of the atmosphere. However, in the absence of an efficient transport
mechanism,
this means that Nitrogen oxides must be produced at low (~ 20 km) altitude,
i.e; by
relativistic electrons. Now, according to the important fluxes of 10 –
20 MeV
electrons observed by the SAMPEX satellite over long time periods
(several
months or years) at L = 1.2 – 2.5 (Li and Temerin, 2001) this may be
possible.
One important point in the project is not only to study the possible
use of
wave field measurements to trace the gyro resonance interactions taking
place
at the equator but also to study if detectable emissions may be
associated with
downward directed electron beams.
A more difficult
problem is the
possible detection of emissions associated with the atmosphere /
ionosphere
coupling indicated by the observation of TLEs. Energetic runaway
electrons
above thunderstorms, driven by the intense QE field following a
positive
cloud-to-ground (+CG) discharge, has been put forth (Roussel
Dupré et al.,
1994, 1996) as a fundamental new plasma acceleration process (Gurevich
et al.,
1992; Bell et al., 1995). Models have been developed by Roussel
Dupré et al. (1998), Yukhimuk
et aL; (1999), Lehtinen
et al. (1999). No
direct measurements of energetic runaway electron beams have yet been
made, and
future direct observations are unlikely due to the localized (~20 km)
lateral
size (Lehtinen et al., 1997) and highly transient (~1ms duration)
nature of the
beams (Lehtinen et al., 2001). However, possible measurable effects of
the
beams in the conjugate hemisphere have been investigated (Lehtinen et
al.,
2001). An important point in the project is the identification of the
emissions
that could allow tracing of the involved processes. ELF radiation
originating
from currents flowing within the body of sprites have been suggested
(Cummer et
al., 1998; Pasko et al., 1998). Considering simultaneous effect of
runaway
breakdown and extensive atmospheric showers, Gurevich et al. (2002)
predicted
the generation of wide band bipolar pulses of radio emission in the
frequency
range 1-10 MHZ. But tests must be made from existing models or even
from
available satellite data. Till now, the only relevant measurement is
the
ground-based detection of radio-pulses associated with cosmic ray
showers
(Ravel et al., 2004). It was performed at a few tens of MHz, but it may
exist
at lower frequencies.
The
method which is proposed to
tackle the above problems is:
(i) to gather scientists
coming from two different communities (plasmasphere,
ionosphere) to make the study as general as possible,
(ii)
to
take time to review and discuss the published results,
(iii) when
possible to test ideas on existing models
(models have been developed by most of the participating groups) and
available
satellite data (CLUSTER, DEMETER),
(iv) to define satellite operations (at least
for DEMETER) and model modifications which may allow to check results
and ideas,
(v) to examine results from complementary
checks,
(vi) to draw conclusions and prepare a final
review.
With
regards to the satellites which
are mentioned above several points need to be made. Several Co-I of the
CLUSTER
mission belong to the proposing group. This will allow an easy access
to the
ULF/ELF/VLF data at the perigee, which is of particular interest for
plasmaspheric
studies. LPCE, who leads the proposal, has the scientific
responsibility for
the low altitude DEMETER satellite which makes wave measurements from
DC to 3.5
MHz. Low resolution events (Dt
³ 1s) may
be studied in the lowest
frequency band (f < 25 kHz) from the “survey mode”. High-resolution
data are
collected via the “burst mode”. In that case short time intervals (1024
points)
of LF and MF waveforms are collected each 2 seconds. Although the
measurement
conditions are not those one may expect on TARANIS, ideas and scenarios
can be
tested. On request the “burst” mode can be triggered over a
geographical region
of interest for the group.
The results of this
study will be of
great interest to the scientific community involved in the study of
TLEs and TGFs. They will be used for the CNES microsatellite TARANIS
poroject (expected start of phase B in 01/2007).
Bell,
T.F., V.P. Pasko,
and U.S.
Inan, Runaway electrons as a source of red sprites in the mesosphere,
Geophys.
res. Lett., 22, 2127, 1995
Callis, L.B.,
R.E.
Boughner, D.N. Baker, R.A. Mewaldt, J.R. Blake, R. Selesnick, J.R.
Cummings, M.
Natarajan, G.M. Mason, and J.E. Mazur, Precipitating electrons:
evidence for
effects on mesospheric odd nitrogen, Geophys. Res. Lett., 23, 15,
101-1904,
1996.
Callis, L.B.,
and
J.D. Lambeth, NOy formed by precipitating electron events in 1991 and
1992:
descent into the stratosphere as observed by ISAMS, Geophys. Res.
Lett., 25,
1875-1878, 1998.
Callis, L.B.,
Stratospheric studies consider crucial question of particle
precipitation, EOS,
82, 27, 297 – 301, 2001.
Callis, L.B.,
M.
Natarajan, and J.D. Lambeth, Solar-atmospheric coupling by electrons
(SOLACE)
3. Comparisons of simulations and observations, 1979 – 1997, issues and
implications, J. Geophys. Res., 106, D7, 7523-7539, 2001.
Callis L.B.,
M.
Natarajan, J.D. Lambeth, Observed and calculated mesospheric NO,
1992-1997,
Geophys. Res. Lett., 29, 2, 10.1029/2001GL013995, 2002.
Cummer S.A.,
U.S.
Inan, T.F. Bell, and C.P. Barrigton-Leigh, ELF radiation produced by
electrical
currents in sprites, Geophys. Res. Lett., 25, 8, 1281-1284, 1998.
Gurevich,
A.V., G.M. Milikh,
and R.A. Roussel-Dupre, Runaway electron mechanism of air breakdown and
preconditioning during a thunderstorm, Phys.
Lett A, 165, 463-468, 1992.
Gurevich A.V.,
L.M.
Dunan, Yu. V. Mededev, K.P. Zybin, Radio emission due to simultaneous
effect of
runaway breakdown and extensive atmospheric showers, Physic Letters A
301,
320-326, 2002.
Huret N., J.P.
Pommereau, F. Lefevre, C.Peubey and M. Pirre : Photochemical modeling
of NO2/O3
ratio variations in the stratosphere along a SAOZ-MIR trajectory around
the
Earth at the tropics, Sixth European Symposium on Ozone, Goteborg,
September
2002.
Lehtinen,
N.G., M.
Walt, U.S. Inan, T.F. Bell, and V.P. Pasko, γ-rayemission produced by a
relativistic beam of runaway electrons accelerated by
quasi-electrostatic
thundercloud fiels, Geophys. Res. Lett., 23, 2645, 1996.
Lehtinen,
N.G.,
T.F. Bell, V.P. Pasko, and U.S. Inan, A two-dimensional model of
runaway electron
beams driven by quasi-electrostatic thundercloud fields, Grophys. Res.
Lett.,
24, 2639, 1997.
Lehtinen,
N.G.,
T.F. Bell, and U.S. Inan, Monte Carlo
simulation of runaway Mev electron breakdown with application to red
sprites
and terrestrial gamma ray flashes, J. Geophys. Res., 104, 24,6999, 1999.
Lehtinen, N.G., U.S.
Inan, and T.F. Bell, Effects of thunderstorm-driven runaway electrons
in the
conjugate hemisphere: purple sprites, ionisation enhancements, and
gamma rays,
J. Geophys. Res., 106, A12, 28,841-28,856, 2001.
Li, X., and
M.A.
Temerin, The electron radiation belt, Space Sci. Rev., 95, 569-580,
2001.
Pasko, V.P., U.S.
Inan, T.F. Bell, and S.C. Reising, Mechanism of ELF radiation from
sprites,
Geophys. Res. Lett., 25, 18, 3493-3496, 1998.
Revel, O., R.
Dallier, L. Denis, H. Gousset, F. Haddard, P. Lautridou, A. Lecacheux, E. Morteau, C. Rosalen and C. Roy, Radio
detection of
cosmic ray air showers by the CODALEMA experiment, Nuclear Instruments
and
Methods in Physics, Research A., 518, 213-215, 2004.
Roussel-Dupré,
R.A., A.V. Gurevich, T.Tunnel, and G.M. Milikh, Kinetic theory of
runaway
breakdown, Phys. Rev., 49, 917, 1994.
Roussel-Dupré,
R.A. and A.V. Gurevich, On runaway
breakdown and upward propagating discharges, J. Geophys. Res. 101, No. A2,
2297, 1996.
Roussel-Dupré, R., E. Symbalisty, Y. Taranenko, and V.
Yukhimuk, Simulations of high-altitude discharges initiated by runaway
breakdown, JASTP, 60, 917 – 940,
1998.
Siskind, D.E.,
G.E.
Nedoluha, C.E. Randall, M. Fromm, J.M. Russell, An assessment of
southern
hemisphere stratospheric NOx enhancements due to transport from the
upper
atmosphere, Geophys. Res. Lett., 27, 3, 329 – 332, 2000.
Yukhimuk, V., R.
Roussel-Dupré, and E.M.D. Symbalisty, On the temporal evolution
of red sprites:
Runaway theory versus data, Geophys. Res. Lett., 26, 679, 1999.
The
expected outputs are :
- specification for space missions dedicated to TLEs and TGFs
- publications of papers on specific points
- a common review paper
Site created and updated by
Christian Hanuise
Comments and suggestions to:
hanuise (at) cnrs-orleans.fr
