scholarly journals Solar wind stream interaction regions throughout the heliosphere

2018 ◽  
Vol 15 (1) ◽  
Author(s):  
Ian G. Richardson
Keyword(s):  
Solar Wind ◽  
Solar Wind Stream ◽  
Interaction Regions

Stream Interaction Regions in the Inner Heliosphere: Insights from the First Four Orbits of Parker Solar Probe

2020 ◽  
Author(s):  
Robert Allen ◽  
George Ho ◽  
Lan Jian ◽  
David Lario ◽  
Dusan Odstrcil ◽  
...  
Keyword(s):  
Solar Wind ◽  
Temporal Evolution ◽  
Geomagnetic Storms ◽  
Solar Wind Stream ◽  
Temporal Development ◽  
Fast Solar Wind ◽  
Interaction Regions ◽  
Radial Evolution ◽  
Accelerated Particles ◽  
Inner Heliosphere

<p>The first four orbits of Parker Solar Probe (PSP) consists of many observations of stream interaction regions (SIRs), which form when fast solar wind streams overtake slower solar wind. While it is known that SIRs accelerate ions in the heliosphere and can trigger geomagnetic storms, the temporal and radial evolution of SIRs is still an active topic of research. During the first four orbits of PSP, SIRs were observed by PSP at small heliospheric distances, as well as at 1 au by the Advanced Composition Explorer (ACE), Wind, and Solar Terrestrial Relations Observatory (STEREO) missions. These SIRs are observed not only at different heliospheric distances, but also at different points in the temporal development of the stream interface. Through analyzing the various SIRs together, insight can be gained in regards to the spatial and temporal evolution of SIR characteristics, as well as to the mechanisms of particle acceleration and transport along the SIR interface. The general characteristics of SIRs observed by PSP during the first four orbits are presented, and an in-depth comparison of a few of the SIR events is conducted to further analyze the evolution of SIR streams in the inner heliosphere. These observations show examples of a fast solar wind stream steepening into an SIR, with evidence of locally accelerated particles via compressive mechanisms at the interface distinguishable from observations of particles likely accelerated at shocks formed at larger heliospheric distances.</p>

scholarly journals Solar wind stream interfaces in corotating interaction regions: New SWICS/Ulysses results

1999 ◽  
Vol 104 (A5) ◽  
pp. 9933-9945 ◽  
Author(s):  
Robert F. Wimmer-Schweingruber ◽  
Rudolf von Steiger ◽  
Raoul Paerli
Keyword(s):  
Solar Wind ◽  
Solar Wind Stream ◽  
Corotating Interaction Regions ◽  
Interaction Regions

Solar wind stream interfaces in corotating interaction regions: SWICS/Ulysses results

1997 ◽  
Vol 102 (A8) ◽  
pp. 17407-17417 ◽  
Author(s):  
Robert F. Wimmer-Schweingruber ◽  
Rudolf von Steiger ◽  
Raoul Paerli
Keyword(s):  
Solar Wind ◽  
Solar Wind Stream ◽  
Corotating Interaction Regions ◽  
Interaction Regions

scholarly journals Space weather: the solar perspective

2021 ◽  
Vol 18 (1) ◽  
Author(s):  
Manuela Temmer
Keyword(s):  
Solar Wind ◽  
Space Weather ◽  
Weather Forecasting ◽  
Interplanetary Space ◽  
Three Dimensions ◽  
Space Weather Forecasting ◽  
Stereo Mission ◽  
Interaction Regions ◽  
Near Future ◽  
First Time

AbstractThe Sun, as an active star, is the driver of energetic phenomena that structure interplanetary space and affect planetary atmospheres. The effects of Space Weather on Earth and the solar system is of increasing importance as human spaceflight is preparing for lunar and Mars missions. This review is focusing on the solar perspective of the Space Weather relevant phenomena, coronal mass ejections (CMEs), flares, solar energetic particles (SEPs), and solar wind stream interaction regions (SIR). With the advent of the STEREO mission (launched in 2006), literally, new perspectives were provided that enabled for the first time to study coronal structures and the evolution of activity phenomena in three dimensions. New imaging capabilities, covering the entire Sun-Earth distance range, allowed to seamlessly connect CMEs and their interplanetary counterparts measured in-situ (so called ICMEs). This vastly increased our knowledge and understanding of the dynamics of interplanetary space due to solar activity and fostered the development of Space Weather forecasting models. Moreover, we are facing challenging times gathering new data from two extraordinary missions, NASA’s Parker Solar Probe (launched in 2018) and ESA’s Solar Orbiter (launched in 2020), that will in the near future provide more detailed insight into the solar wind evolution and image CMEs from view points never approached before. The current review builds upon the Living Reviews article by Schwenn from 2006, updating on the Space Weather relevant CME-flare-SEP phenomena from the solar perspective, as observed from multiple viewpoints and their concomitant solar surface signatures.

scholarly journals Increased electric sail thrust through removal of trapped shielding electrons by orbit chaotisation due to spacecraft body

2009 ◽  
Vol 27 (8) ◽  
pp. 3089-3100 ◽  
Author(s):  
P. Janhunen
Keyword(s):  
Solar Wind ◽  
Three Dimensional ◽  
Electron Gun ◽  
Solar Wind Stream ◽  
Space Propulsion ◽  
Positive Potential ◽  
Trapped Electrons ◽  
Natural Mechanism ◽  
Electric Solar Wind Sail ◽  
Positively Charged

Abstract. An electric solar wind sail is a recently introduced propellantless space propulsion method whose technical development has also started. The electric sail consists of a set of long, thin, centrifugally stretched and conducting tethers which are charged positively and kept in a high positive potential of order 20 kV by an onboard electron gun. The positively charged tethers deflect solar wind protons, thus tapping momentum from the solar wind stream and producing thrust. The amount of obtained propulsive thrust depends on how many electrons are trapped by the potential structures of the tethers, because the trapped electrons tend to shield the charged tether and reduce its effect on the solar wind. Here we present physical arguments and test particle calculations indicating that in a realistic three-dimensional electric sail spacecraft there exist a natural mechanism which tends to remove the trapped electrons by chaotising their orbits and causing them to eventually collide with the conducting tethers. We present calculations which indicate that if these mechanisms were able to remove trapped electrons nearly completely, the electric sail performance could be about five times higher than previously estimated, about 500 nN/m, corresponding to 1 N thrust for a baseline construction with 2000 km total tether length.

CIR versus CME drivers of the ring current during intense magnetic storms

2010 ◽  
Vol 466 (2123) ◽  
pp. 3305-3328 ◽  
Author(s):  
Michael W. Liemohn ◽  
Matt Jazowski ◽  
Janet U. Kozyra ◽  
Natalia Ganushkina ◽  
Michelle F. Thomsen ◽  
...  
Keyword(s):  
Solar Wind ◽  
Boundary Conditions ◽  
Electric Fields ◽  
Data Model ◽  
Goodness Of Fit ◽  
Plasma Boundary ◽  
Magnetic Storms ◽  
Hot Electron ◽  
Interplanetary Coronal Mass Ejections ◽  
Interaction Regions

Ninety intense magnetic storms (minimum Dst value of less than −100 nT) from solar cycle 23 (1996–2005) were simulated using the hot electron and ion drift integrator (HEIDI) model. All 90 storm intervals were run with several electric fields and nightside plasma boundary conditions (five run sets). Storms were classified according to their solar wind driver, including corotating interaction regions (CIRs) and interplanetary coronal mass ejections (ICMEs). Data-model comparisons were made against the observed Dst index (specifically, Dst*) and dayside hot-ion measurements from geosynchronous orbiting spacecraft. It is found that the data-model goodness-of-fit values are different for CIR-driven storms relative to ICME-driven storms. The results are also different for the same storm category for different boundary conditions. None of the CIR-driven events was overpredicted by HEIDI, while the dayside comparisons were comparable for the different drivers. The results imply that the outer magnetosphere is responding differently to the two kinds of solar wind drivers, even though the resulting storm size might be similar. That is, for ICME-driven events, magnetospheric currents inside of geosynchronous orbit dominate the Dst perturbation, while for CIR-driven events, currents outside of this boundary have a systematically larger contribution.

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