Results 61 to 70 of about 2,470 (205)

Origins of Very Low Helium Abundance Streams Detected in the Solar Wind Plasma

The Astrophysical Journal
The abundance of helium ( A _He ) in the solar wind exhibits variations typically in the range from 2% to 5% with respect to solar cycle activity and solar wind velocity. However, there are instances where the observed A _He is exceptionally low (
Yogesh, N. Gopalswamy, D. Chakrabarty, Parisa Mostafavi, Seiji Yashiro, Nandita Srivastava, Leon Ofman   +6 more
doaj   +1 more source

Can Streamer Blobs prevent the Buildup of the Interplanetetary Magnetic Field?

, 1998
Coronal Mass Ejections continuously drag closed magnetic field lines away from the Sun, adding new flux to the interplanetary magnetic field (IMF). We propose that the outward-moving blobs that have been observed in helmet streamers are evidence of ...
A. J. C. Beliën, Gold T., Gosling J. T., Gosling J. T., Gosling J. T., Hiei E., Hundhausen A. J., Illing R. M. E., Kahler S. W., M. K. van Aalst, MacQueen R. M., McComas D. J., McComas D. J., McComas D. J., P. C. H. Martens, Rust D. M.   +15 more
core   +2 more sources

Diamagnetic and Expansion Effects on the Observable Properties of the Slow Solar Wind in a Coronal Streamer [PDF]

The Astrophysical Journal, 2005
The plasma density enhancements recently observed by the Large-Angle Spectrometric Coronagraph (LASCO) instrument onboard the Solar and Heliospheric Observatory (SOHO) spacecraft have sparked considerable interest. In our previous theoretical study of the formation and initial motion of these density enhancements it is found that beyond the helmet cusp
A. F. RAPPAZZO, M. VELLI, EINAUDI, GIORGIO, R. B. DAHLBURG   +3 more
openaire   +3 more sources

PSP/IS⊙IS Observation of a Solar Energetic Particle Event Associated with a Streamer Blowout Coronal Mass Ejection during Encounter 6

The Astrophysical Journal, 2022
Abstract In this paper we examine a low-energy solar energetic particle (SEP) event observed by IS⊙IS’s Energetic Particle Instrument-Low (EPI-Lo) inside 0.18 au on 2020 September 30. This small SEP event has a very interesting time profile and ion composition.
T. Getachew, D. J. McComas, C. J. Joyce, E. Palmerio, E. R. Christian, C. M. S. Cohen, M. I. Desai, J. Giacalone, M. E. Hill, W. H. Matthaeus, R. L. McNutt, D. G. Mitchell, J. G. Mitchell, J. S. Rankin, E. C. Roelof, N. A. Schwadron, J. R. Szalay, G. P. Zank, L.-L. Zhao, B. J. Lynch, T. D. Phan, S. D. Bale, P. L. Whittlesey, J. C. Kasper   +23 more
openaire   +3 more sources

First imaging of corotating interaction regions using the STEREO spacecraft [PDF]

, 2008
Plasma parcels are observed propagating from the Sun out to the large coronal heights monitored by the Heliospheric Imagers (HI) instruments onboard the NASA STEREO spacecraft during September 2007. The source region of these out-flowing parcels is found
A. P. Rouillard, A. Rees, Burlaga, C. H. Perry, C. J. Davis, C. J. Eyles, Crooker, D. Bewsher, Gosling, Harrison, J. A. Davies, Kaiser, Kunow, M. Hapgood, M. Lockwood, McComas, Neugebauer, Odstrčil, Pizzo, R. A. Harrison, R. J. Forsyth, S. R. Crothers, Sheeley, Vourlidas, Wang   +24 more
core   +1 more source

Deriving the Coronal Separatrix‐Web With the WSA Model

Journal of Geophysical Research: Space Physics, Volume 130, Issue 8, August 2025.
Abstract We demonstrate a new capability of the Wang‐Sheeley‐Arge (WSA) model to routinely derive the coronal separatrix web (S‐web) as a standard data product. We describe our methodology for deriving the squashing factor (Q $Q$) and we use Carrington rotation (CR) 2109 to illustrate the validation of our output with that derived from the POT3D model.
Samantha Wallace, Aleida K. Higginson, David G. Simpson, Nicholeen M. Viall, Peter Wyper, C. Nick Arge   +5 more
wiley   +1 more source

Understanding the Variability of Helium Abundance in the Solar Corona Using Three-fluid Modeling and Ultraviolet Observations

The Astrophysical Journal Letters
The variability of helium abundance in the solar corona and the solar wind is an important signature of solar activity, solar cycle, and solar wind sources, as well as coronal heating processes.
Leon Ofman, Yogesh, Silvio Giordano
doaj   +1 more source

Modeling the Solar Corona with an Implicit High-order Reconstructed Discontinuous Galerkin Scheme

The Astrophysical Journal Supplement Series, 2023
The present study aims to apply an implicit high-order reconstructed discontinuous Galerkin (DG) scheme (rDG( P _1 P _2 )) to simulate the steady-state solar corona.
XiaoJing Liu, Xueshang Feng, Man Zhang, Jingmin Zhao   +3 more
doaj   +1 more source

ESTIMATION OF MAGNETIC FIELD IN THE SOLAR CORONAL STREAMERS THROUGH LOW FREQUENCY RADIO OBSERVATIONS

The Astrophysical Journal, 2010
The observations of circularly polarized thermal radio emission from solar coronal streamers at two low frequencies, viz., 77 and 109 MHz, are used to estimate the magnetic field strength (B) at their corresponding radial distances r≈ 1.7 and 1.5 solar radii given by the electron density model of Newkirk.
R. Ramesh, C. Kathiravan, Ch. V. Sastry
openaire   +1 more source

Solar Wind Heavy Ions and Alpha Particles Within Earth's Magnetosphere and Their Variability With Upstream Conditions

Journal of Geophysical Research: Space Physics, Volume 130, Issue 8, August 2025.
Abstract Working toward the goal of understanding solar wind (SW) entry to the Earth's magnetosphere, this study examines solar‐origin ion composition in the magnetotail. During its trajectory, Wind spent a significant amount of time in the Earth's magnetotail, where its SupraThermal Ion Composition Spectrometer (STICS) measured the mass and mass per ...
S. Colón‐Rodríguez, M. W. Liemohn, J. M. Raines, S. T. Lepri   +3 more
wiley   +1 more source