Magnetopause coupling processes and ionospheric responses: a theoretical perspective

1989 ◽  
Vol 328 (1598) ◽  
pp. 79-92 ◽  
Keyword(s):  
Solar Wind ◽  
Energy Transfer ◽  
Theoretical Perspective ◽  
Terrestrial Magnetosphere ◽  
Flux Transfer ◽  
Night Flux ◽  
Coupling Processes ◽  
Made In

In recent years much progress has been made in establishing the mechanisms for mass, momentum and energy transfer from the solar wind into the terrestrial magnetosphere; in particular, the importance of reconnection, at least at disturbed times, is generally agreed. In the simplest circumstances, where dayside and nightside reconnection rates are balanced and steady, the simple open magnetospheric model would pertain. In general, however, reconnection is unsteady, day-night flux transfer occurs in an irregular way and the full complexity of the solar-windmagnetosphere-ionosphere system becomes apparent. A hierarchy of coupling times, for each of which different processes dominate, needs to be considered.

The Effect of Solar Wind Mach Numbers on the Occurrence Rate of Flux Transfer Events at the Dayside Magnetopause

2019 ◽  
Vol 46 (8) ◽  
pp. 4106-4113 ◽  
Author(s):  
C. Chen ◽  
T. R. Sun ◽  
C. Wang ◽  
Z. H. Huang ◽  
B. B. Tang ◽  
...  
Keyword(s):  
Solar Wind ◽  
Occurrence Rate ◽  
Flux Transfer Events ◽  
Dayside Magnetopause ◽  
Mach Numbers ◽  
Flux Transfer

scholarly journals Dayside auroral activity and magnetic flux transfer from the solar wind

1989 ◽  
Vol 16 (1) ◽  
pp. 33-36 ◽  
Author(s):  
M. Lockwood ◽  
P. E. Sandholt ◽  
S. W. H. Cowley
Keyword(s):  
Solar Wind ◽  
Magnetic Flux ◽  
Auroral Activity ◽  
Flux Transfer

Empirical inner boundary conditions and rotation rates for solar wind models

2021 ◽  
Author(s):  
Huw Morgan
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Boundary Conditions ◽  
Coronal Magnetic Field ◽  
Height Range ◽  
Rotation Rates ◽  
Wind Structure ◽  
Solar Wind Structure ◽  
Coronal Electron ◽  
Made In

<p>To date, the inner boundary conditions for solar wind models are either directly or indirectly based on magnetic field extrapolation models of the photosphere. Furthermore, between the photosphere and Earth, there are no other direct empirical constraints on models. New breakthroughs in coronal rotation tomography, applied to coronagraph observations, allow maps of the coronal electron density to be made in the heliocentric height range 4-12 solar radii (Rs). We show that these maps (i) give a new empirical boundary condition for solar wind structure at a height where the coronal magnetic field has become radial, thus avoiding the need to model the complex inner coronal magnetic field, and (ii) give accurate rotation rates for the corona, of crucial importance to the accuracy of solar wind models and forecasts.</p>

scholarly journals Progress on Coronal, Interplanetary, Foreshock, and Outer Heliospheric Radio Emissions

2000 ◽  
Vol 17 (1) ◽  
pp. 22-34 ◽  
Author(s):  
Iver H. Cairns ◽  
P. A. Robinson ◽  
G. P. Zank
Keyword(s):  
Solar Wind ◽  
Plasma Waves ◽  
Recent Theory ◽  
Type Ii ◽  
Solar Radio Bursts ◽  
Radio Emissions ◽  
Source Regions ◽  
Earth’S Bow Shock ◽  
Made In

AbstractType II and III solar radio bursts are associated with shock waves and streams of energetic electrons, respectively, which drive plasma waves and radio emission at multiples of the electron plasma frequency as they move out from the corona into the interplanetary medium. Analogous plasma waves and radiation are observed from the foreshock region upstream of Earth's bow shock. In situ spacecraft observations in the solar wind have enabled major progress to be made in developing quantitative theories for these phenomena that are consistent with available data. Similar processes are believed responsible for radio emissions at 2–3 kHz that originate in the distant heliosphere, from where the solar wind interacts with the local interstellar medium. The primary goal of this paper is to review the observations and theories for these four classes of emissions, focusing on recent progress in developing detailed theories for the plasma waves and radiation in the source regions. The secondary goal is to introduce and review stochastic growth theory, a recent theory which appears quantitatively able to explain the wave observations in type III bursts and Earth's foreshock and is a natural theory to apply to type II bursts, the outer heliospheric emissions, and perhaps astrophysicalemissions.

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

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.

Turbulent energy transfer in bidimensional numerical models of plasma

2021 ◽  
Author(s):  
Rocio Manobanda ◽  
Christian Vasconez ◽  
Denise Perrone ◽  
Raffaele Marino ◽  
Dimitri Laveder ◽  
...  
Keyword(s):  
Solar Wind ◽  
Energy Transfer ◽  
Numerical Models ◽  
Collisionless Plasma ◽  
Space Plasma ◽  
Turbulent Energy ◽  
Turbulent Medium ◽  
Scaling Properties ◽  
Magnetic Diffusivity ◽  
Out Of Plane

<p>Structured, highly variable and virtually collision-free. Space plasma is an unique laboratory for studying the transfer of energy in a highly turbulent environment. This turbulent medium plays an important role in various aspects of the Solar--Wind generation, particles acceleration and heating, and even in the propagation of cosmic rays. Moreover, the Solar Wind continuous expansion develops a strong turbulent character, which evolves towards a state that resembles the well-known hydrodynamic turbulence (Bruno and Carbone). This turbulence is then dissipated from magnetohydrodynamic (MHD) through kinetic scales by different -not yet well understood- mechanisms. In the MHD approach, Kolmogorov-like behaviour is supported by power-law spectra and intermittency measured in observations of magnetic and velocity fluctuations. In this regime, the intermittent cross-scale energy transfer has been extensively described by the Politano--Pouquet (global) law, which is based on conservation laws of the MHD invariants, and was recently expanded to take into account the physics at the bottom of the inertial (or Hall) range, e.g. (Ferrand et al., 2019). Following the 'Turbulence Dissipation Challenge', we study the properties of the turbulent energy transfer using three different bi-dimensional numerical models of space plasma. The models, Hall-MHD (HMHD), Landau Fluid (LF) and Hybrid Vlasov-Maxwell (HVM), were ran in collisionless-plasma conditions, with an out-of-plane ambient magnetic field, and with magnetic diffusivity carefully calibrated in the fluid models. As each model has its own range of validity, it allows us to explore a long-enough range of scales at a period of maximal turbulence activity. Here, we estimate the local and global scaling properties of different energy channels using a, recently introduced, proxy of the local turbulent energy transfer (LET) rate (Sorriso-Valvo et al., 2018). This study provides information on the structure of the energy fluxes that transfers (and dissipates) most of the energy at small scales throughout the turbulent cascade. </p>

What can Observations of Comets Tell Us about the Solar Wind at the Maunder Minimum?

2018 ◽  
Vol 14 (A30) ◽  
pp. 181-183
Author(s):  
N. V. Zolotova ◽  
Y. V. Sizonenko ◽  
M. V. Vokhmyanin ◽  
I. S. Veselovsky
Keyword(s):  
Solar Wind ◽  
Spectral Composition ◽  
Maunder Minimum ◽  
Radius Vector ◽  
Physical Parameters ◽  
Historical Records ◽  
Made In ◽  
Visual Observations

AbstractThis paper discussed whether 17th Century observers left historical records of the plasma tails of comets that would be adequate to enable us to extract the physical parameters of the solar wind. The size of the aberration angle between a comet’s tail and its radius-vector defines the type of the tail: plasma or dust. We considered Bredikhin’s calculations of the parameters for 10 comet tails observed during the Maunder minimum (1645 – 1715). For those comets the angle between the tail’s axis and the radius-vector on average exceeded the value of 10° that is typical for dust tails. It was noted that visual observations of the ion tails of comets are very difficult to make owing to the spectral composition of their radiation, confirming the conclusion that observations of comet tails made in the 17th Century are not suitable for deriving past values of the physical parameters of the solar wind.

Radar studies of high-latitude ionospheric flows

1989 ◽  
Vol 328 (1598) ◽  
pp. 107-118 ◽  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Flow Pattern ◽  
Electric Fields ◽  
Strong Interactions ◽  
Plasma Convection ◽  
Polar Cap ◽  
Incoherent Scatter ◽  
Incoherent Scatter Radars ◽  
Coupling Processes

Strong interactions occur between the solar wind and the Earth’s magnetic field which result in the convection of ionospheric plasma over the polar cap regions. This generally forms a two-cell pattern with westward and eastward flows in the pre- and post-midnight sectors respectively. The flow pattern is sensitive to the flux of the solar wind and the direction of the interplanetary magnetic field. Observations of the flow pattern are thus of considerable value in the interpretation of the magnetosphere-ionosphere coupling processes and in identifying the influence of the solar wind on the Earth’s environment. The plasma convection can be observed by ground-based coherent and incoherent scatter radars and the flow vectors determined. Measurements for a range of flow conditions are presented. These are interpreted in terms of the interactions of the solar wind with the magnetosphere and the resulting electric fields which drive the plasma flows in the ionosphere.

Polydopamine-embedded Cu2−xSe nanoparticles as a sensitive biosensing platform through the coupling of nanometal surface energy transfer and photo-induced electron transfer

The Analyst ◽  
2015 ◽  
Vol 140 (12) ◽  
pp. 4121-4129 ◽  
Author(s):  
Hong Yan Zou ◽  
Peng Fei Gao ◽  
Ming Xuan Gao ◽  
Cheng Zhi Huang
Keyword(s):  
Electron Transfer ◽  
Energy Transfer ◽  
Surface Energy ◽  
Surface Energy Transfer ◽  
Photo Induced Electron Transfer ◽  
Coupling Processes

This study innovatively highlights the mechanistic details of NSET and PET (NSET©PET) coupling processes, and the disclosed mechanism provides new opportunities for sensitive biosensing applications.

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