The variations in the equatorial penetration boundary of solar protons with E sub p = 0.9 to 8.0 MeV during a strong magnetic storm of April 3 to 5, were analyzed. The dynamics of this boundary is compared with the dynamics of the outer trapping boundary of electrons with E sub e = - 0.3 to 0.6 MeV. The solar-proton penetration and the structure of the real magnetic field are studied. The unique data on the thin structure of development of a magnetospheric substorm were obtained for the first time

Glukhov, G. A.

Kratenko, Y. P.

Mineev, Y. V.

English

NASA Technical Reports Server

$48
SH 6.I-I6
DYNAMICS OF THE PENETRATION BOUNDARIES OF SOLAR PROTONS
DURING A STRONG MAGNETIC STORM
G.A. Glukhov, Yu.Po Kratenko
The Tashkent State University, 700095, Tashkent, USSR
Yu.V. _ineev
Institute of Nuclear Physics, Moscow State University,
Moscow II9899, USSR
Abstract. On the basis of the Intercosmos-I9 data, the va-
riations in the equatorial penetration boundary of solar
protons witf_Ep = 0.9-8°0 2_eV during a strong magnetic
storm of April 3-5, I979 are studied. The dynamics of this
boundary is compared with the dynamics of the outer trap-
ping boundary of electrons with Ee = 0.3-0.6 _ieV. Along-
side with the solar-proton penetration we study the struc-
ture of the real magnetic field. The tmiqe data on the
thin structure of development of a magnetospheric substorm
have been obtained for the first time.
In our previous paper /I/ we have analyzed the features
of the latitudinal profiles of the SCR protons with En =
= 0.9-8.0 MeV in the polar regions during a strong magnetic
storm of April 3-5, I979 on the basis of the Intercosmos-I9
data (a perigee of _ 500 km, an apogee of_ IOOO _m, a peri-
od of _- IO0 rain, an inclination of_ 7_°). The present pa-
pem_ is a study of the dynamics of the equatorial penetra-tion boundary (#i_) of the SCR protons for this magnetic
storm (Dst-variation and the AE-index are presented in the
lower par_ of fig.I). The variations in 21_are studied
alongside with the dynamics of the outer trapping bounda-
ries of electrons with E¢ = 0.3-0.6 MeV and Ee = 0.9-I.2
MeV which enables us to investigate the thin structure of
development of magnetospheric substorms. Observations of
electrons and protons were made by a semiconductor telesco-
pe aboard Intercosmos-I9 (IC-I9)/2/.
The outer trapping boundary of electrons was ment to be
the threshold sensitivity of the instrument to the partic-
les with a given energy. This definition of the boundary is •
justified because near the trapping boundary_ there was a
rapid decrease in the particle intensity, liM_was determi-
ned from the onset of a rapid decrease in intensity.
The dynamics of _/i_during the event in question is °
shown in the upper haIf'of fig.I. Data I refer to the day
(open circles) and morning (solid circles) sectors _LT and
data II, to the evening (open circles) and night (solid
circles) sectors. Here is also given the averaged location
of A_ for protons with E_>I I MeV in the day (broken lines
I), morning (solid lines _), evening (broken lines II) and
night (solid lines II) sectors _[ST according to the Cosmos-
900 (C-9OO) and Cosmos-I067) data.
The comparison between the results of observations made
on various satellites shows that at the day and night hours
NLLT the C-900 and C-I067 data, is available, are in good
https://ntrs.nasa.gov/search.jsp?R=19850026776 2020-03-20T16:51:10+00:00Z
34@
SH 6.I-I6
agreement with the 10-19 data. At _he morning hours N_T on
tee main phase of the April, 3 magnetic storm at 20-23 UT
the IC-I9 data are I-2 ° hlgher than the C-900 and C-I067
data, at the maximum Dst the IC-I9 data coincide with the
C-900 and C-I067 data and at the end of the recovery phase
the IC-I9 data coincide or are I° lower than the C-900 and
C-IO67 data at the pre-noon hours (9.5-II.5) _T. A strong
shift of the evening boundary to lower latitudes down to
55° was observed nearly an hour earlier on the IC-I9 as
compared with 0-900 and C-I067. According to the IC-I9 data,
the evening boundary there shifted to larger latitudes, in
conformity with the Ds$-variation, and again to lower lati-
tudes and the second mlnimum in the position of this boun-
dary was observed at the maximum of the main phase of the
storm. The complex analysis of the maia parameters of the
magnetosphere disturbance (Dst , AE) and the parameters of
the interplanetary space (the magnitude and di_ction of
the I_, the solar wind velocity and density) shown that
the strong shift of the evening boundary to lower latitudes
is caused by the development of the magnetospheric substorm.
So, the IC-I9 data confirm the conclusion made in ref.
/3/ about the prior and leading decrease in A_in the eve-
DAng sector, that is connected with the asymmetric intru-
sion of particles of the stomn ring current and the magne-
tic field decrease, yet, this effect is observed on the
phase of development of an individual substorm and not of
the storm as in ref./3/.
The evening boundary of penetration of solar protons
coincides with the night boundary on the recovery phase of
the storm.
The IC-data are obtained at later morning and later
evening hours NLLT which accounts for the differences in the
location of the morning and evening boundaries determined
from the IC-19, C-900 and C-I067 data.
The dynamics of the outer trapping boundary of elec-
trons is shown in the middle part of fig.I. A set of curves
I is for electrons with Ee = 0.3-0.6 _eV and a set of cur-
ves II, for electrons with Ee = 0.9-1.2 MeV. The open cir-
. cles correspond to the data obtained on the dayside and
the solid circles, on the nightside. The position of the
trapping boundaries of electrons is seen to be asymmetric
in the midday-midnight plane and the asymmetry value depends
" on energy: the asymmetry decreases with increasing electron
energy.
On the dayside the position of the trapping boundaries
of electrons depends on rigidity. On the nightside this
dependence is much weaker. As the magnetic field increases
and decreases during the magnetic storms and substorms, the
trapping boundaries shift to higher and lower in variant
latitudes, respectively, in which case the trapping boun-
daries of electrons with different energies come close to
each other as the magnetic field decreases and move away
from each other as the field increases.
SH 6.I-I6
SSO
Cosmos-9_)Q_
]mtercosmos-19 CQsmos-lt)67
i {o f_.5-Io T[--f2-/55 19"5-1_'ghMLT08-f05 -( -096 35 07
]_(I) D0. 1g-22 - [-- f6 -18 I
75" J3,_2_oz -" |--2_ o_12zs/j._6"I°9 t¢_
I .Z-_--o_i_
m ..ot._o.o
•o""-I.,--"------05"07
O0 _ . _ l.-._.. . .. _ 70o
= ,__ __...--- f6-lZ5
- ,_ ,, f.
_ . __2._ - .__
• r I -55
Intercosmos-19 I
I Ee=O_-O6_/eV I
I]_ [/Ee -"0.9-1.2t_ev I, OX__Oh70°. - o.=°O#-1#I'PILT I o-oo°',L, ..,_ .,.
6s I .,%",9-o_ _-/.,i., "'o'"
60 "_.-',_----.Z
- e_ I . -
u _ _._.,o_._/"..60"
-100 AET .
-200 - 200o
- fO00
0
I I I I I I'.l I I ! I I I I I I I I
5 ' _ ' 5
April 1979
Flg.l
351
SH 6.1-16
The comparison between the dynamics of the equatorial
region of penetration of the SCR protons and the outer
trapping boundaries of electrons with E s = 0.3-0.6 _eV and
Ee = 0.9-I.2 MeV shown that on the dayside these boundaries
behave in a similar manner. On the nighside _pe_coincides
to within I° with the trapping boundary o_ electrons with
E_ = 0.3-0.6 MeV except for the time moments within several
mlnutes before the onset of magnetospheric substorms when
the SOR protons are injected into deep L-shells; in this
case the proton intensity peaks near the injection bounda-
ry and then falls down abruptly towards low latitudes. The
intensity maximum can, apparently, be explainedby the p_o-
ton acceleration under the action of the enhanced electric
field. Following the injection the SCR protons with E_ =
= 0.9-8.0 _eV penetrate deep into the trapping regionPof
electrons with Ee = 0.3-0.6 MeV and during strong magneto-
spheric substorms, into the trapping region of prptons with
Ep = 0.9-8.0 MeV.Because of the violation of the adiabatic conditions
of motion, a rapid precipitation of the SCR protons takes
place following the injection in the trapping region of
electrons with Ee = 0.3-0.6 MeV and also in the quasitrap-
ping region on the dayside. The strong p_ecipitation can
also result from the parasitic scattering of the SCR pro-
tons on the electromagnetic radiation of the _ing current
protons.
References
I. Yu.V.Mineev et al. Proc. IS-th Int_.Oos.Ray Conf., Ban-
galore, India, I983, 3, 262-265.
2. Yu.V°_ineev and E.S.Spirkova. Soy.Journal "Vestnik MGU",
series 3, I98I, 22, I, 91-95.
3. L.A.Darchieva et al. Soy. Journal "Geomagnetizm and Aero-
nomy_'_ 1983, 23, 59-6@.


Dynamics of the penetration boundaries of solar protons during a strong magnetic storm

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