scholarly journals Quiet‐Time Spectra and Abundances of Energetic Particles During the 1996 Solar Minimum

1999 ◽  
Vol 518 (1) ◽  
pp. 473-479 ◽  
Author(s):  
Donald V. Reames
Keyword(s):  
Solar Minimum ◽  
Energetic Particles ◽  
Quiet Time

Acceleration of Solar Energetic Particles in CME-Driven Coronal Shocks up to 30 Rs

2021 ◽  
Author(s):  
Kamen Kozarev ◽  
Mohamed Nedal ◽  
Rositsa Miteva ◽  
Pietro Zucca ◽  
Momchil Dechev
Keyword(s):  
Emission Measure ◽  
Realistic Model ◽  
Energetic Particles ◽  
Solar Energetic Particles ◽  
Shock Acceleration ◽  
Quiet Time ◽  
Diffusive Shock Acceleration ◽  
Important Region ◽  
Wave Surfaces ◽  
Mass Ejection

<p>The lower and middle solar corona up to about 30 solar radii is thought to be an important region for early acceleration and transport of solar energetic particles (SEPs) by coronal mass ejection-driven shock waves. There, these waves propagate into a highly variable dynamic medium with steep gradients and rapidly expanding coronal magnetic fields, which modulates the particle acceleration near the shock/wave surfaces, and the way SEPs spread into the heliosphere. We present a study modeling the acceleration of SEPs in over 50 separate global coronal shock events between 1 and 30 solar radii. As part of the SPREAdFAST framework project, we analyzed the interaction of off-limb coronal bright fronts (CBF) observed with the SDO/AIA EUV telescope with realistic model coronal plasma based on results from synoptic magnetohydrodynamic (MHD) and differential emission measure (DEM) models. We used realistic quiet-time proton spectra observed near Earth to form seed suprathermal populations accelerated in our diffusive shock acceleration model (Kozarev & Schwadron, 2016). We summarize our findings and present implications for nowcasting SEP acceleration and heliospheric connectivity.</p>

scholarly journals Solar-minimum quiet time ion energization and outflow in dynamic boundary related coordinates

2008 ◽  
Vol 113 (A7) ◽  
pp. n/a-n/a ◽  
Author(s):  
W. K. Peterson ◽  
L. Andersson ◽  
B. C. Callahan ◽  
H. L. Collin ◽  
J. D. Scudder ◽  
...  
Keyword(s):  
Solar Minimum ◽  
Quiet Time ◽  
Dynamic Boundary ◽  
Ion Energization

Quiet-time solar wind superhalo electrons at solar minimum

2013 ◽  
Author(s):  
Linghua Wang ◽  
Robert P. Lin ◽  
Chadi Salem ◽  
Marc Pulupa ◽  
Davin E. Larson ◽  
...  
Keyword(s):  
Solar Wind ◽  
Solar Minimum ◽  
Quiet Time

SOLAR ENERGETIC PARTICLES

2005 ◽  
Vol 20 (29) ◽  
pp. 6634-6641
Author(s):  
PÉTER KIRÁLY
Keyword(s):  
Solar Cycle ◽  
Interplanetary Space ◽  
Energetic Particles ◽  
Vital Role ◽  
Solar Energetic Particles ◽  
Interstellar Space ◽  
Interplanetary Shocks ◽  
Quiet Time ◽  
Solar Origin ◽  
Suprathermal Particles

Energetic particles recorded in the Earth environment and in interplanetary space have a multitude of origins, i.e. acceleration and propagation histories. At early days practically all sufficiently energetic particles were considered to have come either from solar flares or from interstellar space. Later on, co-rotating interplanetary shocks, the termination shock of the supersonic solar wind, planetary bow shocks and magnetospheres, and also coronal mass ejections (CME) were recognized as energetic particle sources. It was also recognized that less energetic (suprathermal) particles of solar origin and pick-up ions have also a vital role in giving rise to energetic particles in interplanetary disturbances. The meaning of the term "solar energetic particles" (SEP) is now somewhat vague, but essentially it refers to particles produced in disturbances fairly directly related to solar processes. Variation of intensity fluctuations with energy and with the phase of the solar cycle will be discussed. Particular attention will be given to extremes of time variation, i.e. to very quiet periods and to large events. While quiet-time fluxes are expected to shed light on some basic coronal processes, large events dominate the fluctuation characteristics of cumulated fluence, and the change of that fluctuation with energy and with the phase of the solar cycle may also provide important clues. Mainly ISEE-3 and long-term IMP-8 data will be invoked. Energetic and suprathermal particles that may never escape into interplanetary space may play an important part in heating the corona of the sun.

scholarly journals QUIET-TIME INTERPLANETARY ∼2-20 keV SUPERHALO ELECTRONS AT SOLAR MINIMUM

2012 ◽  
Vol 753 (1) ◽  
pp. L23 ◽  
Author(s):  
Linghua Wang ◽  
Robert P. Lin ◽  
Chadi Salem ◽  
Marc Pulupa ◽  
Davin E. Larson ◽  
...  
Keyword(s):  
Solar Minimum ◽  
Quiet Time

Energy spectra of carbon and oxygen - Predictions from HELIOS E6 for Solar Orbiter HET

2020 ◽  
Author(s):  
Johannes Marquardt ◽  
Bernd Heber ◽  
Robert Elftmann ◽  
Robert Wimmer-Schweingruber
Keyword(s):  
Energetic Particle ◽  
Solar Minimum ◽  
Cosmic Ray ◽  
High Energy ◽  
Energy Spectra ◽  
Particle Detector ◽  
Quiet Time ◽  
Transport Models ◽  
Galactic Cosmic Ray ◽  
Insight Into

<p>Anomalous cosmic rays (ACRs) are well-suited to probe the transport conditions of energetic particles in the innermost heliosphere. We revisit the HELIOS Experiment 6 (E6) data in view of the upcoming Solar Orbiter Energetic Particle Detector (EPD) suite that will perform measurements during a comparable solar minimum within the same distance.</p><p>Adapting the HELIOS energy ranges for oxygen and carbon to the ones given by the High Energy Telescope (HET) allows us to determine predictions for the upcoming measurements but also to put constraints on particle transport models that provide new insight into the boundary conditions close to the Sun.</p><p>We present here the adapted energy spectra of galactic cosmic ray (GCR) carbon and oxygen, as well as of ACR oxygen during solar quiet time periods between 1975 to 1977. Due to the higher energy threshold of HET in comparison to E6 gradients of about 20% at 15 MeV/nucleon are expected. The largest ACR gradient measured by E6 was obtained to be about 75% between 9 and 13 MeV/nucleon and 0.4 AU and 1 AU.</p>

scholarly journals Cosmogenic radionuclides reveal an extreme solar particle storm near a solar minimum 9125 years BP

2022 ◽  
Vol 13 (1) ◽  
Author(s):  
Chiara I. Paleari ◽  
Florian Mekhaldi ◽  
Florian Adolphi ◽  
Marcus Christl ◽  
Christof Vockenhuber ◽  
...  
Keyword(s):  
Energy Spectrum ◽  
Solar Minimum ◽  
Ice Cores ◽  
Energetic Particles ◽  
The Sun ◽  
Before Present ◽  
Cosmogenic Radionuclides ◽  
Solar Particle ◽  
Solar Storms ◽  
Instrumental Period

AbstractDuring solar storms, the Sun expels large amounts of energetic particles (SEP) that can react with the Earth’s atmospheric constituents and produce cosmogenic radionuclides such as 14C, 10Be and 36Cl. Here we present 10Be and 36Cl data measured in ice cores from Greenland and Antarctica. The data consistently show one of the largest 10Be and 36Cl production peaks detected so far, most likely produced by an extreme SEP event that hit Earth 9125 years BP (before present, i.e., before 1950 CE), i.e., 7176 BCE. Using the 36Cl/10Be ratio, we demonstrate that this event was characterized by a very hard energy spectrum and was possibly up to two orders of magnitude larger than any SEP event during the instrumental period. Furthermore, we provide 10Be-based evidence that, contrary to expectations, the SEP event occurred near a solar minimum.

Quiet-time properties of low-energy (less than 10 MeV per nucleon) interplanetary ions during solar maximum and solar minimum

1990 ◽  
Vol 363 ◽  
pp. L9 ◽  
Author(s):  
I. G. Richardson ◽  
D. V. Reames ◽  
K.-P. Wenzel ◽  
J. Rodriguez-Pacheco
Keyword(s):  
Solar Minimum ◽  
Solar Maximum ◽  
Low Energy ◽  
Quiet Time

scholarly journals Unusual behavior of quiet-time zonal and vertical plasma drift velocities over Jicamarca during the recent extended solar minimum of 2008

2017 ◽  
Vol 35 (6) ◽  
pp. 1219-1229 ◽  
Author(s):  
Ângela M. Santos ◽  
Mangalathayil A. Abdu ◽  
Jonas R. Souza ◽  
Inez S. Batista ◽  
José H. A. Sobral
Keyword(s):  
Zonal Wind ◽  
Solar Minimum ◽  
Anomalous Behavior ◽  
Quiet Time ◽  
Unusual Behavior ◽  
Plasma Drift ◽  
Ionosphere Model ◽  
Early Afternoon ◽  
Minimum Solar Activity ◽  
Magnetometer Data

Abstract. The influence of the recent deep and prolonged solar minimum on the daytime zonal and vertical plasma drift velocities during quiet time is investigated in this work. Analyzing the data obtained from incoherent scatter radar from Jicamarca (11.95° S, 76.87° W) we observe an anomalous behavior of the zonal plasma drift during June 2008 characterized by lower than usual daytime westward drift and its early afternoon reversal to eastward. As a case study the zonal drift observed on 24 June 2008 is modeled using a realistic low-latitude ionosphere simulated by the Sheffield University Plasmasphere-Ionosphere Model-INPE (SUPIM-INPE). The results show that an anomalously low zonal wind was mainly responsible for the observed anomalous behavior in the zonal drift. A comparative study of the vertical plasma drifts obtained from magnetometer data for some periods of maximum (2000–2002) and minimum solar activity (1998, 2008, 2010) phases reveal a considerable decrease on the E-region conductivity and the dynamo electric field during 2008. However, we believe that the contribution of these characteristics to the unusual behavior of the zonal plasma drift is significantly smaller than that arising from the anomalously low zonal wind. The SUPIM-INPE result of the critical frequency of the F layer (foF2) over Jicamarca suggested a lower radiation flux than that predicted by solar irradiance model (SOLAR2000) for June 2008.

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