scholarly journals Super Strong Geomagnetic Storms and their Relation with Energetic Solar Features and Disturbances in Solar wind Plasma Parameters

2011 ◽  
Vol 2 (1) ◽  
pp. 152-156
Author(s):  
P.L.Verma P.L.Verma ◽  
◽  
Manoj Kumar Mishra ◽  
Monika Mishra ◽  
Preetum Singh ◽  
...  
Keyword(s):  
Solar Wind ◽  
Geomagnetic Storms ◽  
Solar Wind Plasma ◽  
Plasma Parameters

HelioSwarm: The Nature of Turbulence in Space Plasmas

2021 ◽  
Author(s):  
Harlan Spence ◽  
Kristopher Klein ◽  
HelioSwarm Science Team
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Large Scale ◽  
Solar Wind Plasma ◽  
Turbulent Energy ◽  
Space Plasmas ◽  
Plasma Parameters ◽  
Astrophysical Plasmas ◽  
Ion Distributions ◽  
Background Magnetic Field

<p>Recently selected for phase A study for NASA’s Heliophysics MidEx Announcement of Opportunity, the HelioSwarm Observatory proposes to transform our understanding of the physics of turbulence in space and astrophysical plasmas by deploying nine spacecraft to measure the local plasma and magnetic field conditions at many points, with separations between the spacecraft spanning MHD and ion scales.  HelioSwarm resolves the transfer and dissipation of turbulent energy in weakly-collisional magnetized plasmas with a novel configuration of spacecraft in the solar wind. These simultaneous multi-point, multi-scale measurements of space plasmas allow us to reach closure on two science goals comprised of six science objectives: (1) reveal how turbulent energy is transferred in the most probable, undisturbed solar wind plasma and distributed as a function of scale and time; (2) reveal how this turbulent cascade of energy varies with the background magnetic field and plasma parameters in more extreme solar wind environments; (3) quantify the transfer of turbulent energy between fields, flows, and ion heat; (4) identify thermodynamic impacts of intermittent structures on ion distributions; (5) determine how solar wind turbulence affects and is affected by large-scale solar wind structures; and (6) determine how strongly driven turbulence differs from that in the undisturbed solar wind. </p>

scholarly journals Latitudinal extent of large-scale structures in the solar wind

2003 ◽  
Vol 21 (6) ◽  
pp. 1331-1339 ◽  
Author(s):  
H. A. Elliott ◽  
D. J. McComas ◽  
P. Riley
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Spatial Scales ◽  
Coronal Holes ◽  
Solar Wind Plasma ◽  
Ecliptic Plane ◽  
Plasma Parameters ◽  
Field Polarity ◽  
Interplanetary Physics ◽  
Hydrodynamic Code

Abstract. Comparison of solar wind observations from the ACE spacecraft, in the ecliptic plane at ~ 1 AU, and the Ulysses spacecraft as it orbits over the Sun’s poles, provides valuable information about the latitudinal extent and variation of solar wind structures in the heliosphere. While qualitative comparisons can be made using average properties observed at these two locations, the comparison of specific, individual structures requires a procedure to determine if a given structure has been observed by both spacecraft. We use a 1-D hydrodynamic code to propagate ACE plasma measurements out to the distance of Ulysses and adjust for the differing longitudes of the ACE and Ulysses spacecraft. In addition to comparing the plasma parameters and their characteristic profiles, we examine suprathermal electron measurements and magnetic field polarity to help determine if the same features are encountered at both ACE and Ulysses. The He I l 1083 nm coronal hole maps are examined to understand the global structure of the Sun during the time of our heliospheric measurements. We find that the same features are frequently observed when both spacecraft are near the ecliptic plane. Stream structures derived from smaller coronal holes during the rising phase of solar cycle 23 persists over 20°–30° in heliolatitude, consistent with their spatial scales back at the Sun.Key words. Interplanetary physics (solar wind plasma)

Solar wind plasma parameters on Ulysses: Detailed comparison between the URAP and SWOOPS experiments

2001 ◽  
Vol 106 (A8) ◽  
pp. 15665-15675 ◽  
Author(s):  
Karine Issautier ◽  
R. M. Skoug ◽  
J. T. Gosling ◽  
S. P. Gary ◽  
D. J. McComas
Keyword(s):  
Solar Wind ◽  
Solar Wind Plasma ◽  
Detailed Comparison ◽  
Plasma Parameters

Long-term properties of the solar wind and their relation to solar cycles

2020 ◽  
Author(s):  
Anna Salohub ◽  
Jana Šafránkova ◽  
Zdeněk Němeček ◽  
Lubomír Přech ◽  
Tereza Ďurovcová
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Dynamic Pressure ◽  
Solar Wind Speed ◽  
Solar Wind Plasma ◽  
Solar Cycles ◽  
Plasma Parameters ◽  
Wind Spacecraft ◽  
Slow Wind ◽  
Density Dynamic

<p>The solar wind variations during particular solar cycles have been described in many previous studies including the solar cycle 23 that was characterized by a long, deep, and very complex solar minimum with very low values of many solar wind parameters.</p><p>Using statistical methods, we analyzed 25 years of Wind spacecraft measurements with motivation to reveal differences and similarities in magnetic field components and solar wind plasma parameters in individual solar cycles. We tracked the changes of the solar magnetic field strength, and components, solar wind speed, density, dynamic pressure, temperature, and composition). Except quiet solar wind conditions during solar minima and maxima, we also selected significant discontinuities (ICME and CIRs) and investigated their influence on profiles of average parameters. For this, we followed other quantities connected with their presence as their average front normals, regions of transitions between high and slow wind streams, special interplanetary magnetic field orientations, etc.). We discuss a behavior of investigated parameters over solar cycles as well as on shorter time scales (in the order of days and hours).</p>

Small-scale variations of helium abundance in different large-scale solar wind structures

2020 ◽  
Author(s):  
Alexander Khokhlachev ◽  
Maria Riazantseva ◽  
Liudmila Rakhmanova ◽  
Yuri Yermolaev ◽  
Irina Lodkina ◽  
...  
Keyword(s):  
Solar Wind ◽  
Large Scale ◽  
Solar Wind Plasma ◽  
Magnetic Clouds ◽  
Slow Solar Wind ◽  
Small Scale ◽  
Plasma Stream ◽  
Helium Abundance ◽  
Russian Science ◽  
Plasma Parameters

<p>The boundaries between large-scale solar wind streams are often accompanied by sharp changes in helium abundance.  Wherein the high value of relative helium abundance is known as a sign of some large-scale solar wind structures ( for example magnetic clouds). Unlike the steady slow solar wind where the helium abundance is rather stable and equals ~5%, in magnetic clouds its value can grow significantly up to 20% and more, and at the same time helium component becomes more variable.  In this paper we analyze the small-scale variations of solar wind plasma parameters, including the helium abundance variations in different large-scale solar wind streams, especially in magnetic clouds and Sheath regions before them. We use rather long intervals of simultaneous measurements at Spektr-R (spectrometer BMSW) and Wind (spectrometer 3DP) spacecrafts.  We choose the intervals with rather high correlation  level of plasma parameters as a whole to be sure that we are deal with the same plasma stream.  The intervals associated with different large scale-solar wind structures are selected by using of our catalog ftp://ftp.iki.rssi.ru/pub/omni/catalog/. For selected intervals we examine cross-correlation function for Spektr-R and Wind measurements  to reveal the local spatial inhomogeneities by helium abundance which can be observed only at one of spacecrafts, and we determine properties of ones. Such inhomogeneities can be generate by turbulence, which is typically getting more intense in the considered disturbed intervals in the solar wind. The work is supported by Russian Science Foundation grant 16-12-10062.</p>

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