Ion properties of Mercury’s northern cusp under extreme solar wind observed by MESSENGER

2021 ◽  
Author(s):  
Sae Aizawa ◽  
Nicolas André ◽  
Jim Raines
Keyword(s):  
Solar Wind ◽  
Solar Wind Plasma ◽  
Space Environment ◽  
Ion Distribution ◽  
Cusp Region ◽  
Kappa Value ◽  
Orbital Phase ◽  
Plasma Spectrometer ◽  
Wind Events ◽  
First Time

<p>Mercury’s magnetic cusp allows solar wind plasma to precipitate into the magnetosphere, exosphere, and directly to the surface. This precipitation of solar wind leads to the production of neutrals in the exosphere and/or ions in the magnetosphere and thus it has an important role in shaping Mercury’s space environment. Characterizing the ion properties in the cusp region is important for obtaining a better understanding of the Sun-planet interactions and assessing the solar wind penetration in Mercury’s magnetosphere.</p><p>The MErcury Surface, Space ENvironment, GEochemistry, and Ranging (MESSENGER) spacecraft has observed the northern cusp regularly during its orbital phase. We have analyzed plasma data obtained by the Fast Imaging Plasma Spectrometer (FIPS) onboard MESSENGER under extreme solar wind events and compared the resulting ion properties in the northern cusp with those under non-extreme solar wind events for the first time. <span>We found that (1) flux enhancement is confirmed under the extreme solar wind, and (2) the ion distribution in the cusp has a smaller kappa value than in the magnetosheath, suggesting ion acceleration occurs in the magnetosphere.</span></p>

Gravitational and Coulomb Potentials Interference in Heliosphere

2020 ◽  
pp. 93-121
Author(s):  
P.I. Vysikaylo ◽  
N.S. Ryabukha
Keyword(s):  
Solar Wind ◽  
Solar Wind Plasma ◽  
The Sun ◽  
Number Density ◽  
Heavy Particles ◽  
Debye Theory ◽  
Experimental Values ◽  
First Time ◽  
Small Charge ◽  
Coulomb Potentials

Interference of gravitational and Coulomb potentials in the entire heliosphere is considered, it is being manifested in generation of two opposite flows of charged particles: 1) that are neutral or with a small charge to the Sun, and 2) in the form of a solar wind from the Sun. According to the Einstein --- Smoluchowski relation Te(R) = eDe / µe ~ (E/N)0.75 based on the N experimental values (heavy particles number density --- the ne electron concentration), the Te electron temperature in the entire heliosphere was for the first time analytically calculated depending on the charge of the Sun and distance to it R. Calculated values of the registered ion parameters in the solar wind were compared with experimental observations. Reasons for generating the ring current in inhomogeneous heliosphere and inapplicability of the Debye theory in describing processes in the solar wind (plasma with current) are considered

scholarly journals Switchback-like structures observed by Solar Orbiter

2021 ◽  
Author(s):  
Andrey Fedorov ◽  
Philippe Louarn ◽  
Christopher Owen ◽  
Lubomir Prech ◽  
Timothy Horbury ◽  
...  
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Distribution Function ◽  
Field Data ◽  
Solar Wind Plasma ◽  
Time Interval ◽  
Ion Distribution ◽  
Time Intervals ◽  
Radial Magnetic Field ◽  
Magnetic Field Data

<p>During 27th September 2020 NASA Parker Solar Probe (PSP) and ESA-NASA Solar Orbiter (SolO) have been located around the same Carrington longitude and their latitudinal separation was very small as well. Solar wind plasma and magnetic field data obtained throughout this time interval  allows to consider that sometimes the solar wind, observed by both spacecrafts, originates from the same coronal hole region. Inside these time intervals the SolO radial magnetic field experiences several short variations similar to the "switchbacks" regularly observed by PSP. We used the SolO SWA-PAS proton analyzer data to analyze the ion distribution function variations inside such switchback-like events to understand if such events are really "remains" of the alfvenic structures observed below 60 Rs.</p>

scholarly journals Statistical analysis of long-duration low-density solar wind events

2001 ◽  
Vol 19 (1) ◽  
pp. 17-23 ◽  
Author(s):  
S. Watari ◽  
T. Watanabe ◽  
K. Marubashi
Keyword(s):  
Solar Wind ◽  
Dynamic Pressure ◽  
Solar Wind Plasma ◽  
Occurrence Rate ◽  
In Situ Observation ◽  
Low Density ◽  
Wind Condition ◽  
Long Duration ◽  
Interplanetary Physics ◽  
Wind Events

Abstract. Low solar wind density with long duration was measured by in situ observation between 11 and 12 May 1999. As a result of this low-density solar wind condition, the magnetosphere of the Earth expanded considerably. We used a database of one-hour-averaged solar wind (1963–1999) near 1 AU to determine whether or not the observed low-density event was extremely abnormal. As a result it was found that this event has the longest duration in approximately 36 years of solar wind observations. There are three events with density 0.5 cm-3 or less and duration ten hours or longer. They were observed on 4 and 31 July 1979, and 11–12 May 1999. The 4 July 1979 event recurred on 31 July 1979. The events were characterized by low-beta, low Alfven Mach number (MA ), and low dynamic pressure. The occurrence rate of low-density solar wind with density 0.5 cm-3 or less shows several peaks near solar maxima. However, it is difficult to find a clear relationship between the sunspot number and the occurrence rate.Key words. Interplanetary physics (flare and stream dynamics; solar wind plasma; sources of the solar wind)

Quantitative surface damage studies by H.R.E.M.

1989 ◽  
Vol 47 ◽  
pp. 632-633
Author(s):  
S. R. Singh ◽  
H. J. Fan ◽  
L. D. Marks
Keyword(s):  
Solar Wind ◽  
Quantitative Analysis ◽  
Surface Science ◽  
Surface Damage ◽  
Space Environment ◽  
Oxygen Desorption ◽  
The Past ◽  
Diffusion Controlled ◽  
Original Observation ◽  
Substantial Interest

Since the original observation that the surfaces of materials undergo radiation damage in the electron microscope similar to that observed by more conventional surface science techniques there has been substantial interest in understanding these phenomena in more detail; for a review see. For instance, surface damage in a microscope mimics damage in the space environment due to the solar wind and electron beam lithographic operations.However, purely qualitative experiments that have been done in the past are inadequate. In addition, many experiments performed in conventional microscopes may be inaccurate. What is needed is careful quantitative analysis including comparisons of the behavior in UHV versus that in a conventional microscope. In this paper we will present results of quantitative analysis which clearly demonstrate that the phenomena of importance are diffusion controlled; more detailed presentations of the data have been published elsewhere.As an illustration of the results, Figure 1 shows a plot of the shrinkage of a single, roughly spherical particle of WO3 versus time (dose) driven by oxygen desorption from the surface.

scholarly journals A review of the SCOSTEP’s 5-year scientific program VarSITI—Variability of the Sun and Its Terrestrial Impact

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Kazuo Shiokawa ◽  
Katya Georgieva
Keyword(s):  
Solar Wind ◽  
Interplanetary Space ◽  
Solar Wind Plasma ◽  
The Sun ◽  
Scientific Program ◽  
Solar Cycles ◽  
Grand Minimum ◽  
The Earth ◽  
Earth Connection ◽  
Near Future

AbstractThe Sun is a variable active-dynamo star, emitting radiation in all wavelengths and solar-wind plasma to the interplanetary space. The Earth is immersed in this radiation and solar wind, showing various responses in geospace and atmosphere. This Sun–Earth connection variates in time scales from milli-seconds to millennia and beyond. The solar activity, which has a ~11-year periodicity, is gradually declining in recent three solar cycles, suggesting a possibility of a grand minimum in near future. VarSITI—variability of the Sun and its terrestrial impact—was the 5-year program of the scientific committee on solar-terrestrial physics (SCOSTEP) in 2014–2018, focusing on this variability of the Sun and its consequences on the Earth. This paper reviews some background of SCOSTEP and its past programs, achievements of the 5-year VarSITI program, and remaining outstanding questions after VarSITI.

scholarly journals Ulysses solar wind plasma observations at high latitudes

1997 ◽  
Vol 20 (1) ◽  
pp. 15-22 ◽  
Author(s):  
P Riley ◽  
S.J Bame ◽  
B.L Barraclough ◽  
W.C Feldman ◽  
J.T Gosling ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Wind Plasma ◽  
High Latitudes

Thermal properties of the solar wind plasma

Solar Physics ◽  
1971 ◽  
Vol 18 (1) ◽  
pp. 150-164 ◽  
Author(s):  
Tsutomu Toichi
Keyword(s):  
Solar Wind ◽  
Thermal Properties ◽  
Solar Wind Plasma

Ulysses solar wind plasma observations during the declining phase of solar cycle 22

1995 ◽  
Vol 16 (9) ◽  
pp. 85-94 ◽  
Author(s):  
J.L. Phillips ◽  
S.J. Bame ◽  
W.C. Feldman ◽  
J.T. Gosling ◽  
C.M. Hammond ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Cycle ◽  
Solar Wind Plasma
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