scholarly journals PENGARUH ORIENTASI MEDAN MAGNET ANTARPLANET PADA GANGGUAN GEOMAGNET DI LINTANG RENDAH

2016 ◽  
Vol 13 (2) ◽  
pp. 73
Author(s):  
Anton Winarko ◽  
Anwar Santoso
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Geomagnetic Storm ◽  
Interplanetary Space ◽  
Recovery Phase ◽  
Geomagnetic Disturbance ◽  
Wind Condition ◽  
Low Latitude ◽  
Sudden Impulse

Interplanetary Magnetic Field (IMF) is a part of the Solar magnetic field that is carried into interplanetary space by the solar wind. Based on previous study it is known that solar wind condition when reconnection occurs has important role on geomagnetic disturbance. This paper discusses low-latitude geomagnetic field responses to various condition of reconnection, i.e. when north-south component of Interplanetary Magnetic Field (IMF Bz) was south-directed (<0) in long duration, IMF Bz switch to opposite direction after reconnection, and neutral IMF Bz (~0). Case studies show that precondition which IMF Bz<0 prompt more intense geomagnetic storm compared to IMF Bz ~0. At low latitude, precondition of IMF Bz <0 tend to trigger disturbance in the form of geomagnetic storm, while the IMF Bz~0 one could trigger Sudden Impulse. Change of IMF Bz direction after reconnection affected recovery phase acceleration, that was on IMF Bz>0, recovery phase  took less time compared to IMF Bz<0. AbstrakMedan magnet antarplanet (Interplanetary Magnetic Field/IMF) adalah medan magnet matahari yang dibawa oleh angin surya dan menjalar dalam ruang antarplanet. Berdasarkan studi sebelumnya diketahui bahwa kondisi angin surya saat terjadi rekoneksi amat berpengaruh terhadap gangguan geomagnet yang terjadi. Pada makalah ini dibahas respons medan geomagnet di lintang rendah pada berbagai kondisi rekoneksi yaitu pada saat komponen utara-selatan medan magnet antarplanet (IMF Bz) dominan selatan (IMF Bz<0) dalam durasi panjang, IMF Bz berbalik arah setelah rekoneksi, dan  IMF Bz cenderung netral (IMF Bz~0). Dari studi kasus menunjukkan bahwa prakondisi IMF Bz <0 mengakibatkan badai geomagnet yang lebih intens dibandingkan IMF Bz~0. Di lintang rendah, prakondisi IMF Bz<0 cenderung mengakibatkan gangguan berupa badai geomagnet sedangkan IMF Bz~0 dapat memicu Sudden Impulse. Perubahan arah IMF Bz yang terjadi setelah rekoneksi mempengaruhi laju fase pemulihan (recovery phase), yaitu pada IMF Bz>0, fase pemulihannya cenderung berlangsung lebih cepat dibandingkan saat IMF Bz<0.

scholarly journals The relativistic electron response in the outer radiation belt during magnetic storms

2002 ◽  
Vol 20 (7) ◽  
pp. 957-965 ◽  
Author(s):  
R. H. A. Iles ◽  
A. N. Fazakerley ◽  
A. D. Johnstone ◽  
N. P. Meredith ◽  
P. Bühler
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Wind Speed ◽  
Interplanetary Magnetic Field ◽  
Relativistic Electron ◽  
Radiation Belt ◽  
Solar Wind Speed ◽  
Recovery Phase ◽  
Magnetic Storms ◽  
Outer Radiation Belt

Abstract. The relativistic electron response in the outer radiation belt during magnetic storms has been studied in relation to solar wind and geomagnetic parameters during the first six months of 1995, a period in which there were a number of recurrent fast solar wind streams. The relativistic electron population was measured by instruments on board the two microsatellites, STRV-1a and STRV-1b, which traversed the radiation belt four times per day from L ~ 1 out to L ~ 7 on highly elliptical, near-equatorial orbits. Variations in the E > 750 keV and E > 1 MeV electrons during the main phase and recovery phase of 17 magnetic storms have been compared with the solar wind speed, interplanetary magnetic field z-component, Bz , the solar wind dynamic pressure and Dst *. Three different types of electron responses are identified, with outcomes that strongly depend on the solar wind speed and interplanetary magnetic field orientation during the magnetic storm recovery phase. Observations also confirm that the L-shell, at which the peak enhancement in the electron count rate occurs has a dependence on Dst *.Key words. Magnetospheric physics (energetic particles, trapped; storms and substorms) – Space plasma physics (charged particle motion and accelerations)

scholarly journals The Earth's passage of the April 11, 1997 coronal ejecta: geomagnetic field fluctuations at high and low latitude during northward interplanetary magnetic field conditions

1999 ◽  
Vol 17 (10) ◽  
pp. 1245-1250 ◽  
Author(s):  
S. Lepidi ◽  
P. Francia ◽  
U. Villante ◽  
A. Meloni ◽  
A. J. Lazarus ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Geomagnetic Field ◽  
Field Conditions ◽  
Mhd Waves ◽  
Low Latitude ◽  
Terra Nova Bay ◽  
Field Fluctuations ◽  
Terra Nova

Abstract. An analysis of the low frequency geomagnetic field fluctuations at an Antarctic (Terra Nova Bay) and a low latitude (L'Aquila, Italy) station during the Earth's passage of a coronal ejecta on April 11, 1997 shows that major solar wind pressure variations were followed at both stations by a high fluctuation level. During northward interplanetary magnetic field conditions and when Terra Nova Bay is close to the local geomagnetic noon, coherent fluctuations, at the same frequency (3.6 mHz) and with polarization characteristics indicating an antisunward propagation, were observed simultaneously at the two stations. An analysis of simultaneous measurements from geosynchronous satellites shows evidence for pulsations at approximately the same frequencies also in the magnetospheric field. The observed waves might then be interpreted as oscillation modes, triggered by an external stimulation, extending to a major portion of the Earth's magnetosphere. Key words. Magnetospheric physics (MHD waves and instabilities; solar wind-magnetosphere interactions)

scholarly journals Magnetospheric response to the solar wind as indicated by the cross-polar potential drop and the low-latitude asymmetric disturbance field

2001 ◽  
Vol 19 (6) ◽  
pp. 649-653 ◽  
Author(s):  
S. Eriksson ◽  
L. G. Blomberg ◽  
N. Ivchenko ◽  
T. Karlsson ◽  
G. T. Marklund
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Electric Field ◽  
Interplanetary Magnetic Field ◽  
Electric Fields ◽  
Potential Drop ◽  
Plasma Convection ◽  
Low Latitude ◽  
The Cross ◽  
Disturbance Field

Abstract. The cross-polar potential drop Φpc and the low-latitude asymmetric geomagnetic disturbance field, as indicated by the mid-latitude ASY-H magnetic index, are used to study the average magnetospheric response to the solar wind forcing for southward interplanetary magnetic field conditions. The state of the solar wind is monitored by the ACE spacecraft and the ionospheric convection is measured by the double probe electric field instrument on the Astrid-2 satellite. The solar wind-magnetosphere coupling is examined for 77 cases in February and from mid-May to mid-June 1999 by using the interplanetary magnetic field Bz component and the reconnection electric field. Our results show that the maximum correlation between Φpc  and the reconnection electric field is obtained approximately 25 min after the solar wind has reached a distance of 11 RE from the Earth, which is the assumed average position of the magnetopause. The corresponding correlation for ASY-H shows two separate responses to the reconnection electric field, delayed by about 35 and 65 min, respectively. We suggest that the combination of the occurrence of a large magnetic storm on 18 February 1999 and the enhanced level of geomagnetic activity which peaks at Kp = 7- may explain the fast direct response of ASY-H to the solar wind at 35 min, as well as the lack of any clear secondary responses of Φpc  to the driving solar wind at time delays longer than 25 min.Key words. Magnetospheric physics (solar wind-magnetosphere interactions; plasma convection) – Ionosphere (electric fields and currents)

scholarly journals Investigating tensor anisotropy of cosmic rays during large-scale solar wind disturbances

2017 ◽  
Vol 3 (2) ◽  
pp. 20-24 ◽  
Author(s):  
Петр Гололобов ◽  
Peter Gololobov ◽  
Прокопий Кривошапкин ◽  
Prokopy Krivoshapkin ◽  
Гермоген Крымский ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Cosmic Rays ◽  
Interplanetary Magnetic Field ◽  
Large Scale ◽  
Solar Wind Speed ◽  
Forbush Decrease ◽  
Recovery Phase ◽  
Zonal Harmonic ◽  
Solar Wind Disturbances

The observable anisotropy of cosmic rays has first been decomposed into zonal harmonics and components of vector and tensor anisotropy. We examine Forbush decreases in cosmic rays that occurred in November 2001 and November 2004. It is shown that at the beginning of a Forbush decrease an antisunward convective current of cosmic rays predominates; and during the recovery phase, a sunward diffusive current of particles along the interplanetary magnetic field dominates. During the phase of intensity drop, short-time decreases in the second zonal harmonic take place. These decreases occur with abrupt changes of the interplanetary magnetic field intensity and solar wind speed. During the passage of large-scale solar wind disturbances, the tensor anisotropy behaves in a complicated way. To explain its behavior, a further detailed investigation is required.

scholarly journals Manifestation of the Jupiter's synodic period in the solar wind, interplanetary magnetic field and geophysical parameters

2009 ◽  
Vol 5 (S264) ◽  
pp. 452-454
Author(s):  
S. N. Samsonov ◽  
N. G. Skryabin
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Solar Wind Plasma ◽  
Geomagnetic Disturbance ◽  
Physical Parameters ◽  
Plasma Parameters ◽  
Synodic Period ◽  
Solar Wind Parameters ◽  
The Imf

AbstractStudying by the authors of paper of solar wind parameters, namely: density, speed and temperature and also a module of interplanetary magnetic field (IMF) intensity has allowed to find out in them fluctuations with the period of 399 days. From references it is known that this period coincidence with the synodic period of Jupiter. So long as close by the given period another source of such fluctuations is not known we have assumed that fluctuations with the period of 399 days are fluctuations with the synodic period of Jupiter. The change of the solar wind plasma parameters and IMF intensity can lead to the change of the Earth's magnetic field parameters and, as a consequence, to the change of charged particle fluxes in the Earth's magnetosphere. On this assumption the IMF intensity in the Earth's vicinity, geomagnetic disturbance (Kp-index) and riometer absorption for the years of 1986-1996 have been analyzed. The analysis of the data has shown the presence of certain changes of these physical parameters with the period of 399 days. When the Earth and Jupiter were found to be on the same magnetic field line, the IMF intensity was decreasing up to 3.0±0.57, the geomagnetic activity and riometer absorption were decreasing up to 5.2±1.46% and 9.4±2.63%, respectively.

scholarly journals Investigating tensor anisotropy of cosmic rays during large-scale solar wind disturbances

2017 ◽  
Vol 3 (2) ◽  
pp. 22-26
Author(s):  
Петр Гололобов ◽  
Peter Gololobov ◽  
Прокопий Кривошапкин ◽  
Prokopy Krivoshapkin ◽  
Гермоген Крымский ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Cosmic Rays ◽  
Interplanetary Magnetic Field ◽  
Large Scale ◽  
Solar Wind Speed ◽  
Forbush Decrease ◽  
Recovery Phase ◽  
Zonal Harmonic ◽  
Solar Wind Disturbances

The observable anisotropy of cosmic rays has first been decomposed into zonal harmonics and components of vector and tensor anisotropy. We examine Forbush decreases in cosmic rays that occurred in November 2001 and November 2004. It is shown that at the beginning of a Forbush decrease an antisunward convective current of cosmic rays predominates; and during the recovery phase, a sunward diffusive current of particles along the interplanetary magnetic field dominates. During the phase of intensity drop, short-time decreases in the second zonal harmonic take place. These decreases occur with abrupt changes of the interplanetary magnetic field intensity and solar wind speed. During the passage of large-scale solar wind disturbances, the tensor anisotropy behaves in a complicated way. To explain its behavior, a further detailed investigation is required.

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