Study Of The Solar Wind Parameters During The 23rd Solar Cycle

2010 ◽  
Author(s):  
Ch. Katsavrias ◽  
P. Preka-Papadema ◽  
X. Moussas ◽  
Angelos Angelopoulos ◽  
Takis Fildisis
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
23Rd Solar Cycle ◽  
Solar Wind Parameters

scholarly journals Extremely low geomagnetic activity during the recent deep solar cycle minimum

2011 ◽  
Vol 7 (S286) ◽  
pp. 200-209 ◽  
Author(s):  
E. Echer ◽  
B. T. Tsurutani ◽  
W. D. Gonzalez
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Geomagnetic Activity ◽  
Solar Minimum ◽  
Solar Wind Speed ◽  
Sunspot Cycle ◽  
Cycle Minimum ◽  
Current Minimum ◽  
Solar Wind Parameters ◽  
Xix Century

AbstractThe recent solar minimum (2008-2009) was extreme in several aspects: the sunspot number, Rz, interplanetary magnetic field (IMF) magnitude Bo and solar wind speed Vsw were the lowest during the space era. Furthermore, the variance of the IMF southward Bz component was low. As a consequence of these exceedingly low solar wind parameters, there was a minimum in the energy transfer from solar wind to the magnetosphere, and the geomagnetic activity ap index reached extremely low levels. The minimum in geomagnetic activity was delayed in relation to sunspot cycle minimum. We compare the solar wind and geomagnetic activity observed in this recent minimum with previous solar cycle values during the space era (1964-2010). Moreover, the geomagnetic activity conditions during the current minimum are compared with long term variability during the period of available geomagnetic observations. The extremely low geomagnetic activity observed in this solar minimum was previously recorded only at the end of XIX century and at the beginning of the XX century, and this might be related to the Gleissberg (80-100 years) solar cycle.

scholarly journals Electron precipitation events in the lower ionosphere and the geospace conditions

2013 ◽  
Vol 56 (2) ◽  
Author(s):  
José Henrique Fernandez ◽  
Emília Correia
Keyword(s):  
Solar Wind ◽  
Geomagnetic Storms ◽  
Close Association ◽  
Low Frequency ◽  
Lower Ionosphere ◽  
Recovery Phase ◽  
Activity Level ◽  
23Rd Solar Cycle ◽  
Solar Wind Parameters ◽  
Precipitation Events

<p>We present an analysis of localized ionospheric perturbations detected at Comandante Ferraz Brazilian Antarctic Station (McIlwain parameter L~2.25) as fast-amplitude variations of very low frequency (VLF) signals transmitted from Hawaii (NPM, at 21.4 kHz), also known as Trimpi events. The study covers the first six months of 2007, during the period of minimum activity in the 23rd solar cycle. The occurrence of Trimpi events in the Antarctica peninsula region was studied in association with solar-wind parameters in the neighborhood of the Earth (geospace), along with the geomagnetic activity level (Ap, Dst indices). The analysis shows that the Trimpi events occurred predominantly during geomagnetically disturbed periods, but they have a more intricate association with the geospace regimes. The events achieve higher occurrence during the recovery phase of some geomagnetic storms, and also show a close association with electron flux enhancements in the belt region, especially those with higher energy. The higher event incidence occurred a few hours after what we call the 'angle bracket' phenomenon: when the solar wind velocity rises simultaneous with a decrease in its density.</p>

scholarly journals Solar cycle variation of coronal mass ejections contribution to solar wind mass flux

2018 ◽  
Vol 13 (S340) ◽  
pp. 175-176 ◽  
Author(s):  
Wageesh Mishra ◽  
Nandita Srivastava ◽  
Zavkiddin Mirtoshev ◽  
Yuming Wang
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Coronal Mass Ejections ◽  
Mass Flux ◽  
Occurrence Rate ◽  
Solar Cycles ◽  
Solar Cycle Variation ◽  
The Earth ◽  
Solar Wind Parameters

AbstractCoronal Mass Ejections (CMEs) contribute to the perturbation of solar wind in the heliosphere. Thus, depending on the different phases of the solar cycle and the rate of CME occurrence, contribution of CMEs to solar wind parameters near the Earth changes. In the present study, we examine the long term occurrence rate of CMEs, their speeds, angular widths and masses. We attempt to find correlation between near sun parameters of the CMEs with near the Earth measurements. Importantly, we attempt to find what fraction of the averaged solar wind mass near the Earth is provided by the CMEs during different phases of the solar cycles.

scholarly journals Solar cycle by a look of high speed solar wind streams variation

2018 ◽  
Vol 30 ◽  
pp. 26-32
Author(s):  
Simeon Asenovski
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
High Speed ◽  
Solar Cycles ◽  
Speed Solar Wind ◽  
Solar Wind Parameters ◽  
High Speed Solar Wind

In this paper are presented variation of the solar wind parameters during last four solar cycles (21-24) with focus on the high speed solar wind streams (HSS) condition. The averaged values of the parameters for every cycle are calculated and discussed. The results show that Earth is under the HSS influence more than 50% of the total time in each of the last four solar cycles. This fact determines the importance of the studding the behavior of the HSS.

A Statistical Analysis of Solar Wind Parameters and Geomagnetic Indices during the Solar Cycle 23

2015 ◽  
Vol 58 (2) ◽  
pp. 170-178
Author(s):  
SHEN Xiao-Fei ◽  
NI Bin-Bin ◽  
GU Xu-Dong ◽  
ZHOU Chen ◽  
LIU Yong ◽  
...  
Keyword(s):  
Solar Wind ◽  
Statistical Analysis ◽  
Solar Cycle ◽  
Geomagnetic Indices ◽  
Solar Cycle 23 ◽  
Solar Wind Parameters

Solar cycle dependence of solar wind coupling at the Ice Giants

2020 ◽  
Author(s):  
Daniel Gershman ◽  
Gina DiBraccio
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Magnetic Dipole ◽  
Energy Transport ◽  
High Solar Activity ◽  
Dominant Form ◽  
Magnetospheric Convection ◽  
Solar Wind Parameters ◽  
Using Data ◽  
Open Question

&lt;p&gt;The dominant form of mass and energy transport between the Sun and the Ice Giant magnetospheres of Uranus and Neptune remains an open question.&amp;#160; Predictions based on theory suggest that a combination of the weaker internal magnetospheric plasma sources and significantly tilted magnetic dipole fields of Uranus and Neptune may enable increased solar wind-magnetospheric coupling. Much of this coupling is dependent on the local solar wind parameters, specifically the Alfv&amp;#233;nic Mach number&amp;#160;(M&lt;sub&gt;A&lt;/sub&gt;). Despite predictions of transport driven by solar wind coupling, the Voyager 2 flyby of Uranus observed a large M&lt;sub&gt;A&lt;/sub&gt; of ~23 and a loop-like plasmoid in the magnetotail, suggestive of more internal planetary plasma driving.&amp;#160; In order to better constrain the possible scenarios of internally-driven vs. externally-driven magnetospheric convection at a given planet, a quantitative assessment of upstream plasma variations is required.&amp;#160;The interaction between the solar wind and a planetary magnetosphere is often parameterized in terms of M&lt;sub&gt;A&lt;/sub&gt;, with lower values enabling enhanced rates of magnetopause reconnection and energy exchange between the interplanetary and planetary environments. Here we perform a comprehensive analysis of upstream M&lt;sub&gt;A&lt;/sub&gt;&amp;#160;throughout the solar system using data spanning from 0.3 AU to 75 AU, collected by the Helios 1 &amp; 2, Voyager 1 &amp; 2, and Pioneer 10 &amp; 11 spacecraft from 1972-2005.&amp;#160; We find that systematic increases in solar wind magnetic pressure during periods of high solar activity lead to lower-than-expected M&lt;sub&gt;A&amp;#160;&lt;/sub&gt;upstream of the giant planets. These lower M&lt;sub&gt;A&lt;/sub&gt;&amp;#160;values combined with the significant tilt of the magnetic dipole axes at Uranus and Neptune likely result in amplified solar-wind-magnetospheric coupling at solar maximum. The results indicate that magnetospheric dynamics at Uranus and Neptune may be strongly dependent on solar cycle.&lt;/p&gt;

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