Solar flares, magnetic clouds, and geomagnetic storms

Solar Physics ◽  
1993 ◽  
Vol 143 (2) ◽  
pp. 365-372 ◽  
Author(s):  
K. G. Ivanov ◽  
A. F. Harshiladze ◽  
E. P. Romashets
Keyword(s):  
Solar Flares ◽  
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.

scholarly journals The Environment of the Young Earth in the Perspective of An Young Sun

2016 ◽  
Vol 12 (S328) ◽  
pp. 315-328
Author(s):  
Vladimir S. Airapetian
Keyword(s):  
Space Weather ◽  
Solar Flares ◽  
Geomagnetic Storms ◽  
Lower Atmosphere ◽  
Early Earth ◽  
Uv Emission ◽  
Weather Events ◽  
Active Stars ◽  
Magnetohydrodynamic Models ◽  
The Impact

AbstractOur Sun, a magnetically mild star, exhibits space weather in the form of magnetically driven solar explosive events (SEE) including solar flares, coronal mass ejections and energetic particle events. We use Kepler data and reconstruction of X-ray and UV emission from young solar-like stars to recover the frequency and energy fluxes from extreme events from active stars including the young Sun. Extreme SEEs from a magnetically active young Sun could significantly perturb the young Earth's magnetosphere, cause strong geomagnetic storms, initiate escape and introduce chemical changes in its lower atmosphere. I present our recent simulations results based on multi-dimensional multi-fluid hydrodynamic and magnetohydrodynamic models of interactions of extreme CME and SEP events with magnetospheres and lower atmospheres of early Earth and exoplanets around active stars. We also discuss the implications of the impact of these effects on evolving habitability conditions of the early Earth and prebiotic chemistry introduced by space weather events at the early phase of evolution of our Sun.

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

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
Sign in / Sign up

Export Citation Format

Share Document