scholarly journals Magnetospheric ULF waves with increasing amplitude related to solar wind dynamic pressure changes: The Time History of Events and Macroscale Interactions during Substorms (THEMIS) observations

2015 ◽  
Vol 120 (9) ◽  
pp. 7179-7190 ◽  
Author(s):  
X. C. Shen ◽  
Q.‐G. Zong ◽  
Q. Q. Shi ◽  
A. M. Tian ◽  
W. J. Sun ◽  
...  
Keyword(s):  
Solar Wind ◽  
Dynamic Pressure ◽  
Time History ◽  
Solar Wind Dynamic Pressure ◽  
Ulf Waves ◽  
History Of ◽  
Pressure Changes

The effect of solar wind dynamic pressure changes on low and mid-latitude magnetic records

1992 ◽  
Vol 19 (12) ◽  
pp. 1227-1230 ◽  
Author(s):  
C. T. Russell ◽  
M. Ginskey ◽  
S. Petrinec ◽  
G. Le
Keyword(s):  
Solar Wind ◽  
Dynamic Pressure ◽  
Solar Wind Dynamic Pressure ◽  
Pressure Changes

scholarly journals ULF waves excited by negative/positive solar wind dynamic pressure impulses at geosynchronous orbit

2010 ◽  
Vol 115 (A10) ◽  
pp. n/a-n/a ◽  
Author(s):  
X. Y. Zhang ◽  
Q.-G. Zong ◽  
Y. F. Wang ◽  
H. Zhang ◽  
L. Xie ◽  
...  
Keyword(s):  
Solar Wind ◽  
Dynamic Pressure ◽  
Solar Wind Dynamic Pressure ◽  
Geosynchronous Orbit ◽  
Ulf Waves

Magnetic field within magnetosheath jets during northward and southward interplanetary magnetic field conditions

2020 ◽  
Author(s):  
Laura Vuorinen ◽  
Heli Hietala ◽  
Ferdinand Plaschke
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Interplanetary Magnetic Field ◽  
Dynamic Pressure ◽  
Time History ◽  
Magnetic Shear ◽  
History Of ◽  
High Dynamic ◽  
The Magnetic Field ◽  
Magnetopause Reconnection

<p>Downstream of the Earth's quasi-parallel shock, transients with higher earthward velocities than the surrounding magnetosheath plasma are often observed. These transients have been named magnetosheath jets. Due to their high dynamic pressure, jets can cause multiple types of effects when colliding into the magnetopause. Recently, jets have been linked to triggering magnetopause reconnection in case studies by Hietala et al. (2018) and Nykyri et al. (2019). Jets have been proposed to affect magnetopause reconnection in multiple ways. Jets can compress the magnetopause and make it thin enough for reconnection to occur. Jets could also affect the magnetic shear either by indenting the magnetopause or via the magnetic field of the jets themselves. Here we want to study whether the magnetic field of jets can statistically affect magnetopause reconnection. In particular, we are interested in whether jets could enhance reconnection during more quiet northward IMF conditions.</p><p>We statistically study the magnetic field within jets in the subsolar magnetosheath using measurements from the five Time History of Events and Macroscale Interactions during Substorms (THEMIS) spacecraft and OMNI solar wind data from 2008–2011. We investigate jets next to the magnetopause and find that the magnetic field within jets is statistically different compared to the non-jet magnetosheath. Our results suggest that during southward IMF, the non-jet magnetosheath magnetic field itself has more variation than the jets. This suggests that jets should have no statistical, neither enhancing nor suppressing, effect on reconnection during southward IMF. However, during northward IMF, the magnetic field within jets is statistically favorable for enhancing magnetic reconnection at the subsolar magnetopause as around 70 % of these jets exhibit southward fields close to the magnetopause.</p>

Ultra-Low Frequency (ULF) waves originating in solar wind dynamic pressure oscillations and propagating through the magnetosheath to the inner magnetosphere

2020 ◽  
Author(s):  
Marina Georgiou ◽  
Christos Katsavrias ◽  
Ioannis Daglis ◽  
Georgios Balasis
Keyword(s):  
Solar Wind ◽  
Wavelet Transform ◽  
Dynamic Pressure ◽  
Solar Wind Dynamic Pressure ◽  
Slow Solar Wind ◽  
Ulf Waves ◽  
Pressure Oscillations ◽  
Inner Magnetosphere ◽  
Cross Wavelet ◽  
Wave Properties

<p>Several observational studies have shown that ULF oscillations of the solar wind dynamic pressure can drive periodic fluctuations in magnetic field measurements at corresponding frequencies. In this study, we use multi-spacecraft (Cluster, GOES, THEMIS and Van Allen Probes) mission measurements to investigate the propagation of pressure fluctuations-driven pulsations within the Pc5 and Pc4 frequency range (from ~0.5 to 25 mHz) into the magnetosphere. During intervals of slow solar wind — to exclude waves generated by velocity shear at the magnetopause — common periodicities in electromagnetic fields in the magnetosphere and the solar wind driver are first detected in Lomb-Scargle periodograms. Then, using the cross-wavelet transform, we examine the causal relationship and specifically, in cross-wavelet spectra and wavelet transform coherence. Lastly, spatial and temporal variations of wave properties are mapped from beyond the magnetopause to the inner magnetosphere through frequency, polarisation and power signatures of waves detected at the various probes. The observed dependence of wave properties on their localisation offers an excellent source for verification of the role that solar wind dynamic pressure oscillations as driver of ULF waves propagating through the magnetosheath into the dayside and nightside magnetosphere.</p>

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