scholarly journals Earth’s geomagnetic response to solar wind changes associated with solar events at low latitude regions at the TRE MAGDAS Station

2021 ◽  
Vol 880 (1) ◽  
pp. 012009
Author(s):  
R Umar ◽  
S N A Syed Zafar ◽  
N H Sabri ◽  
M H Jusoh ◽  
A Yoshikawa ◽  
...  

Abstract The Sun’s magnetic activity influences disturbances that perturb interplanetary space by producing large fluxes of energetic protons, triggering geomagnetic storms and affecting the ground geomagnetic field. The effect of two solar events, namely Coronal Mass Ejection (CME) and Coronal Holes, on geomagnetic indices (SYM/H), solar wind parameters and ground geomagnetic fields has provided magnetic ground data, which were extracted from the Terengganu (TRE, -4.21° N, 175.91° E) Magnetometer (MAGDAS) station, and investigated in this study. Results show that the physical dynamic mechanism in the Earth’s magnetosphere is triggered by various solar wind parameters associated with CMEs and Coronal hole events during the minimum solar cycle of 24 at low latitudes. It is important to study solar wind-magnetosphere coupling because it has an impact on ground-based technological systems and human activities.

2020 ◽  
Vol 495 (2) ◽  
pp. 2170-2178 ◽  
Author(s):  
Vojtech Rušin ◽  
Paul Prikryl ◽  
Emil A Prikryl

ABSTRACT Light and dark adaptation and luminance contrast enhancement are well-known characteristics of human vision that allow us to observe a wide range of light intensity not fully captured in standard camera images. The naked-eye observations of total eclipses, some recorded with spectacular detail in artists’ paintings, reveal structure that is consistent with images obtained by telescopes equipped with recording media. The actual shape of the corona during a total eclipse depends not only on the phase of the solar cycle but, as can be simply demonstrated, also on the day-to-day variability and spatial distribution of coronal intensity that is determined by solar surface magnetic fields, including the locations of coronal holes that are the sources of high-speed solar wind causing geomagnetic storms. The latter were very similar for the eclipses in 1932, 1994, and 2017, which is the main reason why the naked-eye observations, as well as the processed images (1994 and 2017), of the white-light corona displayed very similar shapes. White-light corona image processing is a useful technique to enhance the contrast to observe fine-scale structure that is consistent with the physics of the solar atmosphere shaped by the magnetic field drawn out into the interplanetary space by solar wind.


2013 ◽  
Vol 8 (S300) ◽  
pp. 473-474
Author(s):  
J. L. Zerbo ◽  
C. Amory-Mazaudier ◽  
F. Ouattara

AbstractIn this study we investigate the time variation of several solar activity, geomagnetic indices, and solar wind parameters (B, V). It is well known that solar wind is one of the main contributing factors to geomagnetic activity and his topology is strongly affect by solar events such as CMEs and coronals. For these two solar events, we study the correlation between PCI and BV during solar cycle phases and point out the close link between PCI and the occurring of CMEs and high wind speed flowing from coronal holes.


2020 ◽  
Vol 12 (3) ◽  
pp. 233-250
Author(s):  
S. Joshi ◽  
K. M. Rao

Coronal mass ejection (CME) and Corotating interaction region (CIR), a dynamic phenomenon associated with the sun, is widely acknowledged as the main causative factor for the occurrence of the geomagnetic storms. In the present investigation, we studied the influence of solar wind parameters and interplanetary magnetic field (IMFBz) on two severe geomagnetic storms (Dst=<-200 nT) occurred during March and June 2015 using magnetic data recorded at four low latitude Indian magnetic observatories namely Jaipur (Rajasthan), Desalpar (Gujarat), Alibag (Maharastra) and Hyderabad (Telangana). Residual H-component of magnetic field distinctly distinguish the different phases of storms. Solar wind density and pressure are more influencive factors during main phase of the magnetic storm with observed high MS coherence (>0.8) with the H-comp. Dynamic spectrum of H-component of magnetic field at low latitudes and solar wind parameters reveals a burst-like nature during the main phase of these storms. During Ionospheric Disturbance Dynamo (Ddyn) for March Storm, it is observed that American sector has downward movement in H-component of magnetic field and prominent attenuation of EEJ in African and Indian sectors. Similarly, for June storm, downward H-component movement is observed in both the American and African sectors and attenuation of EEJ at Indian sector.


2018 ◽  
Vol 36 (6) ◽  
pp. 1607-1630 ◽  
Author(s):  
Eckart Marsch

Abstract. This paper reviews recent aspects of solar wind physics and elucidates the role Alfvén waves play in solar wind acceleration and turbulence, which prevail in the low corona and inner heliosphere. Our understanding of the solar wind has made considerable progress based on remote sensing, in situ measurements, kinetic simulation and fluid modeling. Further insights are expected from such missions as the Parker Solar Probe and Solar Orbiter. The sources of the solar wind have been identified in the chromospheric network, transition region and corona of the Sun. Alfvén waves excited by reconnection in the network contribute to the driving of turbulence and plasma flows in funnels and coronal holes. The dynamic solar magnetic field causes solar wind variations over the solar cycle. Fast and slow solar wind streams, as well as transient coronal mass ejections, are generated by the Sun's magnetic activity. Magnetohydrodynamic turbulence originates at the Sun and evolves into interplanetary space. The major Alfvén waves and minor magnetosonic waves, with an admixture of pressure-balanced structures at various scales, constitute heliophysical turbulence. Its spectra evolve radially and develop anisotropies. Numerical simulations of turbulence spectra have reproduced key observational features. Collisionless dissipation of fluctuations remains a subject of intense research. Detailed measurements of particle velocity distributions have revealed non-Maxwellian electrons, strongly anisotropic protons and heavy ion beams. Besides macroscopic forces in the heliosphere, local wave–particle interactions shape the distribution functions. They can be described by the Boltzmann–Vlasov equation including collisions and waves. Kinetic simulations permit us to better understand the combined evolution of particles and waves in the heliosphere.


2004 ◽  
Vol 22 (2) ◽  
pp. 673-687 ◽  
Author(s):  
S. Watari ◽  
M. Vandas ◽  
T. Watanabe

Abstract. We analyzed observations of the solar activities and the solar wind parameters associated with large geomagnetic storms near the maximum of solar cycle 23. This analysis showed that strong southward interplanetary magnetic fields (IMFs), formed through interaction between an interplanetary disturbance, and background solar wind or between interplanetary disturbances are an important factor in the occurrence of intense geomagnetic storms. Based on our analysis, we seek to improve our understanding of the physical processes in which large negative Bz's are created which will lead to improving predictions of space weather. Key words. Interplanetary physics (Flare and stream dynamics; Interplanetary magnetic fields; Interplanetary shocks)


2009 ◽  
Vol 27 (12) ◽  
pp. 4479-4489 ◽  
Author(s):  
M. M. Bisi ◽  
B. V. Jackson ◽  
J. M. Clover ◽  
P. K. Manoharan ◽  
M. Tokumaru ◽  
...  

Abstract. Interplanetary scintillation (IPS) remote-sensing observations provide a view of the solar wind covering a wide range of heliographic latitudes and heliocentric distances from the Sun between ~0.1 AU and 3.0 AU. Such observations are used to study the development of solar coronal transients and the solar wind while propagating out through interplanetary space. They can also be used to measure the inner-heliospheric response to the passage of coronal mass ejections (CMEs) and co-rotating heliospheric structures. IPS observations can, in general, provide a speed estimate of the heliospheric material crossing the observing line of site; some radio antennas/arrays can also provide a radio scintillation level. We use a three-dimensional (3-D) reconstruction technique which obtains perspective views from outward-flowing solar wind and co-rotating structure as observed from Earth by iteratively fitting a kinematic solar wind model to these data. Using this 3-D modelling technique, we are able to reconstruct the velocity and density of CMEs as they travel through interplanetary space. For the time-dependent model used here with IPS data taken from the Ootacamund (Ooty) Radio Telescope (ORT) in India, the digital resolution of the tomography is 10° by 10° in both latitude and longitude with a half-day time cadence. Typically however, the resolutions range from 10° to 20° in latitude and longitude, with a half- to one-day time cadence for IPS data dependant upon how much data are used as input to the tomography. We compare reconstructed structures during early-November 2004 with in-situ measurements from the Wind spacecraft orbiting the Sun-Earth L1-Point to validate the 3-D tomographic reconstruction results and comment on how these improve upon prior reconstructions.


2020 ◽  
Author(s):  
James M. Weygand ◽  
Paul Prikryl ◽  
Reza Ghoddousi-Fard ◽  
Lidia Nikitina ◽  
Bharat S. R. Kunduri

&lt;p&gt;High-speed streams (HSS) from coronal holes dominate solar wind structure in the absence of coronal mass ejections during solar minimum and the descending branch of solar cycle. Prominent and long-lasting coronal holes produce intense co-rotating interaction regions (CIR) on the leading edge of high-speed plasma streams that cause recurrent ionospheric disturbances and geomagnetic storms. Through solar wind coupling to the magnetosphere-ionosphere-atmosphere (MIA) system they affect the ionosphere and neutral atmosphere at high latitudes, and, at mid to low latitudes, by the transmission of the electric fields [1] and propagation of atmospheric gravity waves from the high-latitude lower thermosphere [2].&lt;/p&gt;&lt;p&gt;The high-latitude ionospheric structure, caused by precipitation of energetic particles, strong ionospheric currents and convection, results in changes of the GPS total electron content (TEC) and rapid variations of GPS signal amplitude and phase, called scintillation [3]. The GPS phase scintillation is observed in the ionospheric cusp, polar cap and auroral zone, and is particularly intense during geomagnetic storms, substorms and auroral breakups. Phase scintillation index is computed for a sampling rate of 50 Hz by specialized GPS scintillation receivers from the Canadian High Arctic Ionospheric Network (CHAIN). A proxy index of phase variation is obtained from dual frequency measurements of geodetic-quality GPS receivers sampling at 1 Hz, which include globally distributed receivers of the RT-IGS network that are monitored by the Canadian Geodetic Survey in near-real-time [4]. Temporal and spatial changes of TEC and phase variations following the arrivals of HSS/CIRs [5] are investigated in the context of ionospheric convection and equivalent ionospheric currents derived from&amp;#160; a ground magnetometer network using the spherical elementary current system method [6,7].&lt;/p&gt;&lt;p&gt;The Joule heating and Lorentz forcing in the high-latitude lower thermosphere have long been recognized as sources of internal atmospheric gravity waves (AGWs) [2] that propagate both upward and downward, thus providing vertical coupling between atmospheric layers. In the ionosphere, they are observed as traveling ionospheric disturbances (TIDs) using various techniques, e.g., de-trended GPS TEC maps [8].&lt;/p&gt;&lt;p&gt;In this paper we examine the influence on the Earth&amp;#8217;s ionosphere and atmosphere of a long-lasting HSS/CIRs from recurrent coronal holes at the end of solar cycles 23 and 24. The solar wind MIA coupling, as represented by the coupling function [9], was strongly increased during the arrivals of these HSS/CIRs.&lt;/p&gt;&lt;p&gt;&amp;#160;&lt;/p&gt;&lt;p&gt;[1] Kikuchi, T. and K. K. Hashimoto, Geosci. Lett. , 3:4, 2016.&lt;/p&gt;&lt;p&gt;[2] Hocke, K. and K. Schlegel, Ann. Geophys., 14, 917&amp;#8211;940, 1996.&lt;/p&gt;&lt;p&gt;[3] Prikryl, P., et al., J. Geophys. Res. Space Physics, 121, 10448&amp;#8211;10465, 2016.&lt;/p&gt;&lt;p&gt;[4] Ghoddousi-Fard et al., Advances in Space Research, 52(8), 1397-1405, 2013.&lt;/p&gt;&lt;p&gt;[5] Prikryl et al. Earth, Planets and Space, 66:62, 2014.&lt;/p&gt;&lt;p&gt;[6] Amm O., and A. Viljanen, Earth Planets Space, 51, 431&amp;#8211;440, 1999.&lt;/p&gt;&lt;p&gt;[7] Weygand J.M., et al., J. Geophys. Res., 116, A03305, 2011.&lt;/p&gt;&lt;p&gt;[8] Tsugawa T., et al., Geophys. Res. Lett., 34, L22101, 2007.&lt;/p&gt;&lt;p&gt;[9] Newell P. T., et al., J. Geophys. Res., 112, A01206, 2007.&lt;/p&gt;


Solar Physics ◽  
2007 ◽  
Vol 240 (2) ◽  
pp. 315-330 ◽  
Author(s):  
Bojan Vršnak ◽  
Manuela Temmer ◽  
Astrid M. Veronig

Author(s):  
Huseyin Cavus ◽  
Aysel Ibrahim Karafistan

The release of magnetic field and plasma from the solar atmosphere (i.e. coronal mass ejections-CMEs and solar wind) resulting from solar magnetic activity can produce shock waves and geomagnetic storms. Shock waves are known to occur while the solar ejected particles alter from the supersonic to the subsonic regime. Especially, in the supersonic case for the flow of compressible gas interaction of shock waves with viscosity plays a key role for space weather broadcasts. Therefore, the major objective of this paper was to search the outcome of viscosity in the shocks subsequently detected after the CMEs occurred on December 18, 1999 and April 4, 2001 by using the previous modelling study of [1].  


2017 ◽  
Vol 14 (2) ◽  
pp. 17
Author(s):  
Anwar Santoso ◽  
Mamat Rahimat ◽  
Rasdewita Kesumaningrum ◽  
Siska Filawati

Space weather research is the principal activity at the Space Science Center, Lapan to learn characteristics and generator source of the space weather so that can mitigate its the impact on the Earth's environment as mandated in Law No. 21 Year 2013. One of them is the phenomenon of geomagnetic storms. Geomagnetic storms caused by the entry of solar wind together with the IMF Bz that leads to the south. The behavior of the solar wind parameters together with the IMF Bz before geomagnetic storms can determine the formation of geomagnetic storms that caused it. In spite that, by the solar wind parameters and IMF Bz behavior before geomagnetic storm can be estimated its intensity through the equation Dst * = 1.599 * Ptotal - 34.48. The result of this equation is obtained that the Dst minimum deviation between the raw data and the output of this equation to the geomagnetic storm events on March 17, 2013 is about of -2.51 nT or 1.9% and on the geomagnetic storm events on February 19, 2014 is about of 2.77 nT or 2, 5%. Thus, the equation Dst * = 1.599 * Ptotal - 34.48 is very good for the estimation of geomagnetic storms.


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