Low-frequency waves in the solar wind near Neptune

1991 ◽  
Vol 18 (6) ◽  
pp. 1071-1074 ◽  
Author(s):  
Ming Zhang ◽  
J. W. Belcher ◽  
J. D. Richardson ◽  
V. M. Vasyliunas ◽  
R. P. Lepping ◽  
...  
Keyword(s):  
Solar Wind ◽  
Low Frequency ◽  
Low Frequency Waves

EXCITATION OF LOW-FREQUENCY WAVES IN THE SOLAR WIND BY NEWBORN INTERSTELLAR PICKUP IONS H+AND He+AS SEEN BY VOYAGER AT 4.5 AU

2010 ◽  
Vol 724 (2) ◽  
pp. 1256-1261 ◽  
Author(s):  
Colin J. Joyce ◽  
Charles W. Smith ◽  
Philip A. Isenberg ◽  
Neil Murphy ◽  
Nathan A. Schwadron
Keyword(s):  
Solar Wind ◽  
Low Frequency ◽  
Pickup Ions ◽  
Low Frequency Waves

Association of low-frequency waves with suprathermal ions in the upstream solar wind

1979 ◽  
Vol 6 (3) ◽  
pp. 209-212 ◽  
Author(s):  
G. Paschmann ◽  
N. Sckopke ◽  
S. J. Bame ◽  
J. R. Asbridge ◽  
J. T. Gosling ◽  
...  
Keyword(s):  
Solar Wind ◽  
Low Frequency ◽  
Suprathermal Ions ◽  
Upstream Solar Wind ◽  
Low Frequency Waves

scholarly journals Occurrence rate of ultra-low frequency waves in the foreshock of Mercury increases with heliocentric distance

2021 ◽  
Vol 12 (1) ◽  
Author(s):  
N. Romanelli ◽  
G. A. DiBraccio
Keyword(s):  
Solar Wind ◽  
Heliocentric Distance ◽  
Low Frequency ◽  
Occurrence Rate ◽  
Eccentric Orbit ◽  
Low Intensity ◽  
Magnetometer Data ◽  
Favorable Conditions ◽  
Open Question ◽  
Low Frequency Waves

AbstractStudies of Mercury’s foreshock have analyzed in detail the properties of ultra-low frequency waves. However, an open question remains in regards to understanding favorable conditions for these planetary foreshocks waves. Here, we report that 0.05–0.41 Hz quasi-monochromatic waves are mostly present under quasi-radial and relatively low intensity Interplanetary Magnetic Field, based on 17 Mercury years of MESSENGER Magnetometer data. These conditions are consistent with larger foreshock size and reflection of solar wind protons, their most likely source. Consequently, we find that the wave occurrence rate increases with Mercury’s heliocentric distance. Detection of these waves throughout Mercury’s highly eccentric orbit suggests the conditions for backstreaming protons are potentially present for all of Mercury’s heliocentric distances, despite the relatively low solar wind Alfvén Mach number regime. These results are relevant for planetary magnetospheres throughout the solar system, and the magnetospheres of exoplanets, and provide knowledge of particle acceleration mechanisms occurring inside foreshocks.

scholarly journals Upstream Ultra-Low Frequency Waves Observed by MESSENGER's Magnetometer: Implications for Particle Acceleration at Mercury's Bow Shock

2020 ◽  
Author(s):  
Norberto Romanelli ◽  
Gina DiBraccio ◽  
Daniel Gershman ◽  
Guan Le ◽  
Christian Mazelle ◽  
...  
Keyword(s):  
Solar Wind ◽  
Wave Amplitude ◽  
Solar Wind Speed ◽  
Low Frequency ◽  
Space Environment ◽  
Occurrence Rate ◽  
Frequency Range ◽  
S Waves ◽  
Mercury Surface ◽  
Low Frequency Waves

<p>In this work we perform the first statistical analysis of the main properties of waves observed in the 0.05–0.41 Hz frequency range in the Hermean foreshock by the MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) Magnetometer. Although we find similar polarization properties to the '30 s' waves observed at the Earth's foreshock, the normalized wave amplitude (∼0.2) and occurrence rate (∼0.5%) are much smaller. This suggests significant lower backstreaming proton fluxes, due to the relatively low solar wind Alfvenic Mach number around Mercury. These differences could also be related to the relatively smaller foreshock size and/or more variable solar wind conditions. Furthermore, we estimate that the speed of resonant backstreaming protons in the solar wind reference frame (likely source for these waves) ranges between 0.95 and 2.6 times the solar wind speed. The closeness between this range and what is observed at other planetary foreshocks suggests that similar acceleration processes are responsible for this energetic population and might be present in the shocks of exoplanets.</p>

Ultra-low frequency foreshock waves at Venus and Mercury in a global hybrid simulation

2020 ◽  
Author(s):  
Riku Jarvinen ◽  
Esa Kallio ◽  
Tuija I. Pulkkinen
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Large Scale ◽  
Low Frequency ◽  
Hybrid Simulation ◽  
Bow Shock ◽  
Upstream Region ◽  
Ulf Waves ◽  
Solar Wind Interaction ◽  
Low Frequency Waves

<p>We study the solar wind interaction with Venus and Mercury in a 3-dimensional global hybrid simulation where ions are treated as particles and electrons are a charge-neutralizing fluid. We concentrate on the formation of large-scale ultra-low frequency (ULF) waves in ion foreshocks and their dependence on the solar wind and interplanetary magnetic field conditions. The ion foreshock forms in the upstream region ahead of the quasi-parallel bow shock, where the angle between the shock normal and the magnetic field is smaller than about 45 degrees. The magnetic connection with the bow shock allows backstreaming of the solar wind ions leading to the formation of the ion foreshock. This kind of beam-plasma configuration is a source of free energy for the excitation of plasma waves. The foreshock ULF waves convect downstream with the solar wind flow and encounter the bow shock. We compare the waves between Venus and Mercury, and analyze the coupling of the ULF waves with the planetary ion acceleration at Venus.</p> <p>References:</p> <p>Jarvinen R., Alho M., Kallio E., Pulkkinen T.I., 2020, Oxygen Ion Escape From Venus Is Modulated by Ultra-Low Frequency Waves, Geophys. Res. Lett., 47, 11, doi:10.1029/2020GL087462</p> <p>Jarvinen R., Alho M., Kallio E., Pulkkinen T.I., 2020, Ultra-low frequency waves in the ion foreshock of Mercury: A global hybrid modeling study, Mon. Notices Royal Astron. Soc., 491, 3, 4147-4161, doi:10.1093/mnras/stz3257</p>

Low-frequency waves associated with Langmuir waves in solar wind

1995 ◽  
Vol 100 (A3) ◽  
pp. 3417-3426 ◽  
Author(s):  
G. Thejappa ◽  
Donat G. Wentzel ◽  
R. G. Stone
Keyword(s):  
Solar Wind ◽  
Low Frequency ◽  
Langmuir Waves ◽  
Low Frequency Waves

scholarly journals 49. The Interplanetary Plasma and the Heliosphere

1979 ◽  
Vol 17 (1) ◽  
pp. 199-213
Author(s):  
A. Hewish
Keyword(s):  
Solar Wind ◽  
Heliocentric Distance ◽  
Solar Magnetic Field ◽  
Interplanetary Space ◽  
Low Frequency ◽  
Surface Heat ◽  
Solar Origin ◽  
Interplanetary Plasma ◽  
Principal Energy ◽  
Low Frequency Waves

It is now generally recognized that the solar wind represents that part of the solar corona which is not confined by the solar magnetic field, and therefore escapes into interplanetary space. The escaping gas is heated by sources of solar origin (presumably low frequency waves) to about 2 x 106 K within a distance less than (1/20) R from the sun’s surface; although the solar wind temperature decreases thereafter, heating sources may continue to act through 1 a.u. heliocentric distance. A transition from subsonic to supersonic flow occurs within a few solar radii of the sun’s surface, heat conduction representing the principal energy supply for the acceleration of the solar wind. However, additional accelerating processes may also be active.

On the generation of low-frequency waves in the solar wind in the front of the bow shock

1976 ◽  
Vol 24 (3) ◽  
pp. 261-267 ◽  
Author(s):  
M.S. Kovner ◽  
V.V. Lebedev ◽  
T.A. Plyasova-Bakounina ◽  
V.A. Troitskaya
Keyword(s):  
Solar Wind ◽  
Low Frequency ◽  
Bow Shock ◽  
Low Frequency Waves
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