scholarly journals Dynamic responses of the Earth's radiation belts during periods of solar wind dynamic pressure pulse based on normalized superposed epoch analysis

2016 ◽  
Vol 121 (9) ◽  
pp. 8523-8536 ◽  
Author(s):  
Binbin Ni ◽  
Zheng Xiang ◽  
Xudong Gu ◽  
Yuri Y. Shprits ◽  
Chen Zhou ◽  
...  
Keyword(s):  
Solar Wind ◽  
Pressure Pulse ◽  
Dynamic Pressure ◽  
Radiation Belts ◽  
Dynamic Responses ◽  
Solar Wind Dynamic Pressure ◽  
Superposed Epoch Analysis ◽  
Epoch Analysis ◽  
Earth's Radiation Belts

scholarly journals Responses of Earth's radiation belts to solar wind dynamic pressure variations in 2002 analyzed using multisatellite data and Kalman filtering

2013 ◽  
Vol 118 (7) ◽  
pp. 4400-4414 ◽  
Author(s):  
Binbin Ni ◽  
Yuri Y. Shprits ◽  
Reiner H. W. Friedel ◽  
Richard M. Thorne ◽  
Marianne Daae ◽  
...  
Keyword(s):  
Solar Wind ◽  
Kalman Filtering ◽  
Dynamic Pressure ◽  
Radiation Belts ◽  
Solar Wind Dynamic Pressure ◽  
Earth's Radiation Belts

scholarly journals Multi-satellite simultaneous observations of magnetopause and atmospheric losses of radiation belt electrons during an intense solar wind dynamic pressure pulse

2016 ◽  
Vol 34 (5) ◽  
pp. 493-509 ◽  
Author(s):  
Zheng Xiang ◽  
Binbin Ni ◽  
Chen Zhou ◽  
Zhengyang Zou ◽  
Xudong Gu ◽  
...  
Keyword(s):  
Solar Wind ◽  
Radiation Belt ◽  
Pressure Pulse ◽  
Electron Flux ◽  
Dynamic Pressure ◽  
Energetic Electron ◽  
Solar Wind Dynamic Pressure ◽  
Angle Scattering ◽  
Radiation Belt Electrons ◽  
Atmospheric Loss

<p><strong>Abstract.</strong> Radiation belt electron flux dropouts are a kind of drastic variation in the Earth's magnetosphere, understanding of which is of both scientific and societal importance. Using electron flux data from a group of 14 satellites, we report multi-satellite simultaneous observations of magnetopause and atmospheric losses of radiation belt electrons during an event of intense solar wind dynamic pressure pulse. When the pulse occurred, magnetopause and atmospheric loss could take effect concurrently contributing to the electron flux dropout. Losses through the magnetopause were observed to be efficient and significant at <i>L</i> ≳ 5, owing to the magnetopause intrusion into <i>L</i> ∼ 6 and outward radial diffusion associated with sharp negative gradient in electron phase space density. Losses to the atmosphere were directly identified from the precipitating electron flux observations, for which pitch angle scattering by plasma waves could be mainly responsible. While the convection and substorm injections strongly enhanced the energetic electron fluxes up to hundreds of keV, they could delay other than avoid the occurrence of electron flux dropout at these energies. It is demonstrated that the pulse-time radiation belt electron flux dropout depends strongly on the specific interplanetary and magnetospheric conditions and that losses through the magnetopause and to the atmosphere and enhancements of substorm injection play an essential role in combination, which should be incorporated as a whole into future simulations for comprehending the nature of radiation belt electron flux dropouts.</p>

scholarly journals On the response of ionospheric electrojets to solar wind discontinuities

2009 ◽  
Vol 27 (10) ◽  
pp. 3791-3803 ◽  
Author(s):  
M. Palmroth ◽  
T. I. Pulkkinen ◽  
J. Polvi ◽  
A. Viljanen ◽  
P. Janhunen
Keyword(s):  
Solar Wind ◽  
Dynamic Pressure ◽  
Pressure Change ◽  
Solar Wind Dynamic Pressure ◽  
Simultaneous Increase ◽  
Sudden Increase ◽  
Step Size ◽  
Ionospheric Response ◽  
Superposed Epoch Analysis ◽  
The Imf

Abstract. We investigate the ionospheric response to solar wind discontinuities as detected by the IE index computed from IMAGE ground magnetometers. The solar wind discontinuities include both sudden increases as well as decreases of the solar wind dynamic pressure, recorded by the SWEPAM instrument of the ACE spacecraft during the period 1998–2004. In our statistical study, we identify four categories of events: 1) sudden increases of the dynamic pressure with a simultaneous increase of the interplanetary magnetic field (IMF) magnitude; 2) sudden increases of the dynamic pressure accompanied with a simultaneous decrease of the IMF; 3) sudden decreases of the dynamic pressure accompanied with a sudden increase of the IMF; and 4) sudden decreases of the dynamic pressure with relatively steady IMF. We perform a superposed epoch analysis for the four event categories to distinguish the ionospheric response. We find that the IE index increases/decreases in response to the solar wind dynamic pressure increases/decreases regardless of the simultaneous change in the IMF or the amount of estimated input energy. We investigate the magnitude of the ionospheric response according to the IMF north-south direction, the dynamic pressure step size as well as the pressure level prior the dynamic pressure change. We find that the ionospheric result is augmented for larger pressure steps, while the prior IMF has a role only in some of the event categories. We also perform global MHD simulation runs to investigate the ionospheric dissipation rate during such solar wind discontinuities, and find that the simulation results are in good qualitative accordance with the observational statistical results.

Dusk side clockwise vortex generation and aurora intensity decrease after Solar Wind Dynamic Pressure Decrease

2021 ◽  
Author(s):  
Jinyan Zhao ◽  
Quanqi Shi ◽  
Anmin Tian ◽  
Ruilong Guo ◽  
Xiao-Chen Shen
Keyword(s):  
Solar Wind ◽  
Pressure Pulse ◽  
Dynamic Pressure ◽  
Simulation Method ◽  
Solar Wind Dynamic Pressure ◽  
Ionospheric Currents ◽  
The Earth ◽  
Sudden Decrease ◽  
Pulse Arrival ◽  
Observation Results

&lt;p&gt;A solar wind dynamic pressure increase/decrease leads to the compression/expansion of the Earth&amp;#8217;s magnetosphere. In response, field-aligned currents, which are carried by precipitating or escaping plasma particles, are generated in the magnetosphere and in lead to variations in the auroral intensity. In this study, we investigate magnetospheric and ionospheric responses (including magnetospheric plasma vortex, ionospheric currents and aurorae) to a sudden decrease in solar wind dynamic pressure (SW P&lt;sub&gt;dyn&lt;/sub&gt;), which is critical for further understanding of the solar wind-magnetosphere-ionosphere coupling. We focused on a SW P&lt;sub&gt;dyn&lt;/sub&gt; decrease event that monitored by OMNI. A counter-clockwise plasma vortex was generated in the dusk side magnetosphere uncovered by using MHD simulation method and a clockwise equivalent ionospheric currents (EIC) vortex was generated in the dusk side ionosphere within about ten minutes after the pressure pulse arrival. Simultaneously, the observation results of Spherical Elementary Currents (SECs) showed that the EIC vortex region is dominated by downward field-aligned currents and the ground-based All-Sky Imager (ASI) observations in the vicinity of this EIC vortex showed that the aurorae diminished. These observations are consistent with the scenario proposed by Shi et al. (2014) that flow vortices in the magnetosphere generated by SW P&lt;sub&gt;dyn&lt;/sub&gt; sudden decrease carry downward field-aligned currents into the dusk side ionosphere, generating ionospheric current vortex and thereby modulating auroral activity on the dusk side.&lt;/p&gt;

Superposed Epoch Analysis of High Latitude Ionospheric Joule Heating during Major Geomagnetic Storms over three Solar Cycles

2018 ◽  
Vol 13 (S340) ◽  
pp. 67-68
Author(s):  
K. J. Suji ◽  
P. R. Prince
Keyword(s):  
Solar Wind ◽  
Joule Heating ◽  
High Latitude ◽  
Geomagnetic Storms ◽  
Dynamic Pressure ◽  
Basic Structure ◽  
Proton Density ◽  
Solar Cycles ◽  
Superposed Epoch Analysis ◽  
Epoch Analysis

AbstractSuperposed epoch analysis (SPEA) is commonly used to determine some basic structure in a collection of geophysical time series. The present study tries to analyze ionospheric Joule heating response at high latitudes, to the prevailing solar wind and IMF conditions on the basis of SPEA. Major geomagnetic storms (CME driven) over three consecutive solar cycles (SC 22, 23 and 24) have been selected. Ascending phase, solar maximum, and declining phase are investigated separately, for each solar cycle, to find out crucial controlling parameters for the generation of high-latitude ionospheric Joule heating. SPEA results show that, IMF parameters such as IMF By, IMF Bz, IMF clock angle and solar wind parameters such as dynamic pressure and proton density influence Joule heating production rate significantly. Meanwhile, the relentlessness of the other parameters such as IMFBt and solar wind bulk speed show that they have poor impact on Joule heating.

Electron drift echoes induced by negative solar wind dynamic pressure pulses

2020 ◽  
Author(s):  
Xiaohan Ma ◽  
Qiugang Zong ◽  
Yixin Hao ◽  
Seth Claudepierre ◽  
Ying Liu
Keyword(s):  
Solar Wind ◽  
Electric Field ◽  
Relativistic Electron ◽  
Pressure Pulse ◽  
Dynamic Pressure ◽  
Energetic Electron ◽  
Interplanetary Shock ◽  
Solar Wind Dynamic Pressure ◽  
Electron Drift ◽  
Field Variation

&lt;div&gt; &lt;div&gt; &lt;div&gt; &lt;p&gt;Sudden dropouts of the relativistic electron fluxes with drift echoes are closely related to a&amp;#160;positive solar wind dynamic pressure pulse, such as an interplanetary shock impact on the&amp;#160;magnetosphere. In this study, we further examine how magnetospheric energetic particles&amp;#160;response to a negative solar wind dynamic pressure pulse on the 11th May 2017. During&amp;#160;this event, sudden dropouts of energetic electron fluxes with an energy of 200 keV&amp;#8764;750&amp;#160;keV and enhancements of the relativistic electron fluxes of 0.85 MeV&amp;#8764;2.7 MeV were observed simultaneously by both Van Allen Probes. The periodic electron flux dropout-recovery or enhancement-decay signatures, which are attributed to electron drift behaviors,&amp;#160;exhibited energy dependence. Based on the electron phase space density profile and the&amp;#160;induced electric field variation, we interpreted this phenomenon as the consequence of radially outward transportationss of electrons caused by the electric field impulse induced by the&amp;#160;negative dynamic pressure pulse.&lt;/p&gt; &lt;/div&gt; &lt;/div&gt; &lt;/div&gt;

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