A large‐scale view of Space Technology 5 magnetometer response to solar wind drivers

<div>Simulation results from a global magnetohydrodynamic model of the solar corona and the solar wind are compared with Parker Solar Probe's (PSP) observations during its first several orbits. The fully three-dimensional model (Usmanov et al., 2018, ApJ, 865, 25) is based on Reynolds-averaged mean-flow equations coupled with turbulence transport equations. The model accounts for effects of electron heat conduction, Coulomb collisions, Reynolds stresses, and heating of protons and electrons via nonlinear turbulent cascade. Turbulence transport equations for turbulence energy, cross helicity, and correlation length are solved concurrently with the mean-flow equations. We specify boundary conditions at the coronal base using solar synoptic magnetograms and calculate plasma, magnetic field, and turbulence parameters along the PSP trajectory. We also accumulate data from all orbits considered, to obtain the trends observed as a function of heliocentric distance. Comparison of simulation results with PSP data show general agreement. Finally, we generate synthetic fluctuations constrained by the local rms turbulence amplitude given by the model, and compare properties of this synthetic turbulence with PSP observations.</div>

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HelioSwarm: The Nature of Turbulence in Space Plasmas

10.5194/egusphere-egu21-12092 ◽

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

Recently selected for phase A study for NASA&#8217;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.&#160;&#160;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.&#160;

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Prospective White-light Imaging and In Situ Measurements of Quiescent Large-scale Solar-wind Streams from the Parker Solar Probe and Solar Orbiter

The Astrophysical Journal ◽

10.3847/1538-4357/aae978 ◽

2018 ◽

Vol 868 (2) ◽

pp. 137 ◽

Cited By ~ 3

Author(s):

Ming Xiong ◽

Jackie A. Davies ◽

Xueshang Feng ◽

Bo Li ◽

Liping Yang ◽

...

Keyword(s):

Solar Wind ◽

White Light ◽

Large Scale ◽

In Situ Measurements ◽

White Light Imaging

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Solar cycle changes of large-scale solar wind structure

Proceedings of the International Astronomical Union ◽

10.1017/s1743921309992912 ◽

2009 ◽

Vol 5 (S264) ◽

pp. 356-358 ◽

Cited By ~ 3

Author(s):

P. K. Manoharan

Keyword(s):

Solar Wind ◽

Solar Cycle ◽

Large Scale ◽

Interplanetary Space ◽

The Sun ◽

Wind Structure ◽

Level Of Activity ◽

Solar Wind Structure ◽

Current Minimum ◽

Inner Heliosphere

AbstractIn this paper, I present the results on large-scale evolution of density turbulence of solar wind in the inner heliosphere during 1985–2009. At a given distance from the Sun, the density turbulence is maximum around the maximum phase of the solar cycle and it reduces to ~70%, near the minimum phase. However, in the current minimum of solar activity, the level of turbulence has gradually decreased, starting from the year 2005, to the present level of ~30%. These results suggest that the source of solar wind changes globally, with the important implication that the supply of mass and energy from the Sun to the interplanetary space has significantly reduced in the present low level of activity.

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Latitudinal extent of large-scale structures in the solar wind

Annales Geophysicae ◽

10.5194/angeo-21-1331-2003 ◽

2003 ◽

Vol 21 (6) ◽

pp. 1331-1339 ◽

Cited By ~ 2

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)

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Magnetosheath-cusp interface

Annales Geophysicae ◽

10.5194/angeo-22-183-2004 ◽

2004 ◽

Vol 22 (1) ◽

pp. 183-212 ◽

Cited By ~ 20

Author(s):

S. Savin ◽

L. Zelenyi ◽

S. Romanov ◽

I. Sandahl ◽

J. Pickett ◽

...

Keyword(s):

Boundary Layer ◽

Solar Wind ◽

Magnetic Fields ◽

Large Scale ◽

Traditional Approach ◽

Qualitative Difference ◽

Small Scale ◽

Nonlinear Phenomena ◽

Solar Wind Interaction ◽

Linear Superposition

Abstract. We advance the achievements of Interball-1 and other contemporary missions in exploration of the magnetosheath-cusp interface. Extensive discussion of published results is accompanied by presentation of new data from a case study and a comparison of those data within the broader context of three-year magnetopause (MP) crossings by Interball-1. Multi-spacecraft boundary layer studies reveal that in ∼80% of the cases the interaction of the magnetosheath (MSH) flow with the high latitude MP produces a layer containing strong nonlinear turbulence, called the turbulent boundary layer (TBL). The TBL contains wave trains with flows at approximately the Alfvén speed along field lines and "diamagnetic bubbles" with small magnetic fields inside. A comparison of the multi-point measurements obtained on 29 May 1996 with a global MHD model indicates that three types of populating processes should be operative: large-scale (∼few RE) anti-parallel merging at sites remote from the cusp; medium-scale (few thousandkm) local TBL-merging of fields that are anti-parallel on average; small-scale (few hundredkm) bursty reconnection of fluctuating magnetic fields, representing a continuous mechanism for MSH plasma inflow into the magnetosphere, which could dominate in quasi-steady cases. The lowest frequency (∼1–2mHz) TBL fluctuations are traced throughout the magnetosheath from the post-bow shock region up to the inner magnetopause border. The resonance of these fluctuations with dayside flux tubes might provide an effective correlative link for the entire dayside region of the solar wind interaction with the magnetopause and cusp ionosphere. The TBL disturbances are characterized by kinked, double-sloped wave power spectra and, most probably, three-wave cascading. Both elliptical polarization and nearly Alfvénic phase velocities with characteristic dispersion indicate the kinetic Alfvénic nature of the TBL waves. The three-wave phase coupling could effectively support the self-organization of the TBL plasma by means of coherent resonant-like structures. The estimated characteristic scale of the "resonator" is of the order of the TBL dimension over the cusps. Inverse cascades of kinetic Alfvén waves are proposed for forming the larger scale "organizing" structures, which in turn synchronize all nonlinear cascades within the TBL in a self-consistent manner. This infers a qualitative difference from the traditional approach, wherein the MSH/cusp interaction is regarded as a linear superposition of magnetospheric responses on the solar wind or MSH disturbances. Key words. Magnetospheric physics (magnetopause, cusp, and boundary layers) – Space plasma physics (turbulence; nonlinear phenomena)

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MESSENGER observations of planetary ion enhancements at Mercury’s northern magnetospheric cusp during Flux Transfer Event Showers

10.21203/rs.3.rs-1138782/v1 ◽

2021 ◽

Author(s):

Weijie Sun ◽

James Slavin ◽

Anna Milillo ◽

Ryan Dewey ◽

Stefano Orsini ◽

...

Keyword(s):

Solar Wind ◽

Large Scale ◽

Transfer Event ◽

Order Of Magnitude ◽

In Situ Observations ◽

Flux Transfer ◽

Magnetospheric Cusp ◽

Upward Moving ◽

Entry Layer

Abstract At Mercury, several processes can release ions and neutrals out of the planet’s surface. Here we present enhancements of dayside planetary ions in the solar wind entry layer during flux transfer event (FTE) “showers” near Mercury’s northern magnetospheric cusp. In this entry layer, solar wind ions are accelerated and move downward (i.e. planetward) toward the cusps, which sputter upward-moving planetary ions within 1 minute. The precipitation rate is enhanced by an order of magnitude during FTE showers and the neutral density of the exosphere can vary by >10% due to this FTE-driven sputtering. These in situ observations of enhanced planetary ions in the entry layer likely correspond to an escape channel of Mercury’s planetary ions, and the large-scale variations of the exosphere observed on minute-timescales by ground-based telescopes. Comprehensive, future multi-point measurements made by BepiColombo will greatly enhance our understanding of the processes contributing to Mercury’s dynamic exosphere and magnetosphere.

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