scholarly journals Differences in geomagnetic storms driven by magnetic clouds and ICME sheath regions

2007 ◽  
Vol 34 (2) ◽  
Author(s):  
T. I. Pulkkinen ◽  
N. Partamies ◽  
K. E. J. Huttunen ◽  
G. D. Reeves ◽  
H. E. J. Koskinen
Keyword(s):  
Geomagnetic Storms ◽  
Magnetic Clouds

scholarly journals Concurrent effect of Alfvén waves and planar magnetic structure on geomagnetic storms

2019 ◽  
Vol 490 (3) ◽  
pp. 3440-3447 ◽  
Author(s):  
Zubair I Shaikh ◽  
Anil Raghav ◽  
Geeta Vichare ◽  
Ankush Bhaskar ◽  
Wageesh Mishra ◽  
...  
Keyword(s):  
Magnetic Structure ◽  
Geomagnetic Storms ◽  
Recovery Phase ◽  
Alfven Waves ◽  
Magnetic Clouds ◽  
Alfvén Waves ◽  
Fast Recovery ◽  
Interplanetary Coronal Mass Ejection ◽  
Mass Ejection

ABSTRACT Generally, interplanetary coronal mass ejection (ICME) triggers intense and strong geomagnetic storms. It has been established that the ICME sheath-moulded planar magnetic structure enhances the amplitude of the storms. Alfvén waves embedded in ICME magnetic clouds or high solar streams including corotating interacting regions (CIRs) in turn extend the recovery phase of the storm. Here, we investigate a geomagnetic storm with a very complex temporal profile with multiple decreasing and recovery phases. We examine the role of planar magnetic structure (PMS) and Alfvén waves in the various phases of the storm. We find that fast decrease and fast recovery phases are evident during transit of PMS regions, whereas a slight decrease or recovery is found during the transit of regions embedded with Alfvénic fluctuations.

scholarly journals Magnetic field disturbances in the sheath region of a super-sonic interplanetary magnetic cloud

2008 ◽  
Vol 26 (10) ◽  
pp. 3153-3158 ◽  
Author(s):  
E. Romashets ◽  
M. Vandas ◽  
S. Poedts
Keyword(s):  
Magnetic Field ◽  
Geomagnetic Storms ◽  
Magnetic Cloud ◽  
The Body ◽  
Magnetic Clouds ◽  
Shock Surface ◽  
Sheath Region ◽  
Magnetic Field Magnitude ◽  
The Magnetic Field ◽  
Magnetic Disturbances

Abstract. It is well-known that interplanetary magnetic clouds can cause strong geomagnetic storms due to the high magnetic field magnitude in their interior, especially if there is a large negative Bz component present. In addition, the magnetic disturbances around such objects can play an important role in their "geo-effectiveness". On the other hand, the magnetic and flow fields in the CME sheath region in front of the body and in the rear of the cloud are important for understanding both the dynamics and the evolution of the interplanetary cloud. The "eventual" aim of this work is to calculate the magnetic field in this CME sheath region in order to evaluate the possible geo-efficiency of the cloud in terms of the maximum |Bz|-component in this region. In this paper we assess the potential of this approach by introducing a model with a simplified geometry. We describe the magnetic field between the CME shock surface and the cloud's boundary by means of a vector potential. We also apply our model and present the magnetic field distribution in the CME sheath region in front of the body and in the rear of the cloud formed after the event of 20 November 2003.

Observations and simulations of foreshock waves during magnetic clouds

2020 ◽  
Author(s):  
Lucile Turc ◽  
Owen Roberts ◽  
Martin Archer ◽  
Minna Palmroth ◽  
Markus Battarbee ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Numerical Simulations ◽  
Wave Field ◽  
Geomagnetic Storms ◽  
Wave Activity ◽  
Bow Shock ◽  
Magnetic Clouds ◽  
Direction Parallel ◽  
High Magnetic Field Strength ◽  
The Waves

<p>The foreshock is a region of intense wave activity, situated upstream of the quasi-parallel sector of the terrestrial bow shock. The most common type of waves in the Earth's ion foreshock are quasi-monochromatic fast magnetosonic waves with a period of about 30 s. In this study, we investigate how the foreshock wave field is modified when magnetic clouds, a subset of coronal mass ejections driving the most intense geomagnetic storms, interact with near-Earth space. Using observations from the Cluster constellation, we find that the average period of the fast magnetosonic waves is significantly shorter than the typical 30 s during magnetic clouds, due to the high magnetic field strength inside those structures, consistent with previous works. We also show that the quasi-monochromatic waves are replaced by a superposition of waves at different frequencies. Numerical simulations performed with the hybrid-Vlasov model Vlasiator consistently show that an enhanced upstream magnetic field results in less monochromatic wave activity in the foreshock. The global view of the foreshock wave field provided by the simulation further reveals that the waves are significantly smaller during magnetic clouds, both in the direction parallel and perpendicular to the wave vector. We estimate the transverse extent of the waves using a multi-spacecraft analysis technique and find a good agreement between the numerical simulations and the spacecraft measurements. This suggests that the foreshock wave field is structured over smaller scales during magnetic clouds. These modifications of the foreshock wave properties are likely to affect the regions downstream - the bow shock, the magnetosheath and possibly the magnetosphere - as foreshock waves are advected earthward by the solar wind.</p>

On the relationship between magnetic clouds and the great geomagnetic storms associated with the period 1995–2006

2011 ◽  
Vol 73 (11-12) ◽  
pp. 1372-1379 ◽  
Author(s):  
M.A. Hidalgo ◽  
J.J. Blanco ◽  
F.J. Alvarez ◽  
T. Nieves-Chinchilla
Keyword(s):  
Geomagnetic Storms ◽  
Magnetic Clouds ◽  
The Relationship

Compound streams, magnetic clouds, and major geomagnetic storms

1987 ◽  
Vol 92 (A6) ◽  
pp. 5725 ◽  
Author(s):  
L. F. Burlaga ◽  
K. W. Behannon ◽  
L. W. Klein
Keyword(s):  
Geomagnetic Storms ◽  
Magnetic Clouds

Relationships Among Magnetic Clouds, CMES, and Geomagnetic Storms

Solar Physics ◽  
2006 ◽  
Vol 239 (1-2) ◽  
pp. 449-460 ◽  
Author(s):  
C. C. Wu ◽  
R. P. Lepping ◽  
N. Gopalswamy
Keyword(s):  
Geomagnetic Storms ◽  
Magnetic Clouds

scholarly journals Solar cycle effect on geomagnetic storms caused by interplanetary magnetic clouds

2006 ◽  
Vol 24 (12) ◽  
pp. 3383-3389 ◽  
Author(s):  
C.-C. Wu ◽  
R. P. Lepping
Keyword(s):  
Solar Wind ◽  
Geomagnetic Storm ◽  
Solar Minimum ◽  
Geomagnetic Storms ◽  
Solar Maximum ◽  
Solar Wind Speed ◽  
Magnetic Clouds ◽  
Active Period ◽  
Quiet Period ◽  
Solar Wind Parameters

Abstract. We investigated geomagnetic activity which was induced by interplanetary magnetic clouds during the past four solar cycles, 1965–1998. We have found that the intensity of such geomagnetic storms is more severe in solar maximum than in solar minimum. In addition, we affirm that the average solar wind speed of magnetic clouds is faster in solar maximum than in solar minimum. In this study, we find that solar activity level plays a major role on the intensity of geomagnetic storms. In particular, some new statistical results are found and listed as follows. (1) The intensity of a geomagnetic storm in a solar active period is stronger than in a solar quiet period. (2) The magnitude of negative Bzmin is larger in a solar active period than in a quiet period. (3) Solar wind speed in an active period is faster than in a quiet period. (4) VBsmax in an active period is much larger than in a quiet period. (5) Solar wind parameters, Bzmin, Vmax and VBsmax are correlated well with geomagnetic storm intensity, Dstmin during a solar active period. (6) Solar wind parameters, Bzmin, and VBsmax are not correlated well (very poorly for Vmax) with geomagnetic storm intensity during a solar quiet period. (7) The speed of the solar wind plays a key role in the correlation of solar wind parameters vs. the intensity of a geomagnetic storm. (8) More severe storms with Dstmin≤−100 nT caused by MCs occurred in the solar active period than in the solar quiet period.

Elliptical magnetic clouds and geomagnetic storms

2008 ◽  
Vol 56 (3-4) ◽  
pp. 492-500 ◽  
Author(s):  
I. Antoniadou ◽  
A. Geranios ◽  
M. Vandas ◽  
M. Panagopoulou ◽  
O. Zacharopoulou ◽  
...  
Keyword(s):  
Geomagnetic Storms ◽  
Magnetic Clouds

Simulation of geomagnetic storms during the passage of magnetic clouds

1995 ◽  
Vol 22 (13) ◽  
pp. 1749-1752 ◽  
Author(s):  
James Chen ◽  
Steven Slinker ◽  
Joel A. Fedder ◽  
John G. Lyon
Keyword(s):  
Geomagnetic Storms ◽  
Magnetic Clouds
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