Results 61 to 70 of about 205 (182)

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

Exploiting White-Light Observations to Improve Estimates of Magnetic Connectivity

Frontiers in Astronomy and Space Sciences, 2021
The Solar Orbiter (SolO) and Parker Solar Probe missions have opened up new challenges for the heliospheric scientific community. Their proximity to the Sun and their high quality measurements allow us to investigate, for the first time, potential ...
Nicolas Poirier, Alexis P. Rouillard, Athanasios Kouloumvakos, Alexis Przybylak, Naïs Fargette, Raphaël Pobeda, Victor Réville, Rui F. Pinto, Rui F. Pinto, Mikel Indurain, Matthieu Alexandre   +10 more
doaj   +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

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

Slow Solar Wind: Origin in an Independent Small‐Scale Solar Dynamo

Geophysical Research Letters, Volume 52, Issue 13, 16 July 2025.
Abstract Separation of the solar wind (SW) into three flow types (coronal mass ejections (CMEs), high speed streams (HSSs), and slow solar wind (SSW)) reveals an inverse relationship between the percentage of time Earth spends in SSW during a year and its annually averaged magnetic field strength (B).
E. W. Cliver, I. G. Richardson, S. F. Martin   +2 more
wiley   +1 more source

Heliospheric current sheet inclinations at Venus and Earth [PDF]

Annales Geophysicae, 1999
We investigate the inclinations of heliospheric current sheet at two sites in interplanetary space, which are generated from the same solar source.
G. Ma, G. Ma, K. Marubashi, T. Maruyama
doaj   +1 more source

Source and Propagation of a Streamer Blowout Coronal Mass Ejection Observed by the Parker Solar Probe

The Astrophysical Journal Supplement Series, 2020
Abstract In the first orbit of the Parker Solar Probe (PSP), in situ thermal plasma and magnetic field measurements were collected as close as 35 R Sun from the Sun, an environment that had not been previously explored.
Korreck, Kelly, Szabo, Adam, Chinchilla, Teresa Nieves, Lavraud, Benoit, Luhmann, Janet, Niembro, Tatiana, Higginson, Aleida, Alzate, Nathalia, Wallace, Samantha, Paulson, Kristoff, Rouillard, Alexis, Kouloumvakos, Athanasios, Poirier, Nicolas, Kasper, Justin, Case, A., Stevens, Michael, Bale, Stuart, Pulupa, Marc, Whittlesey, Phyllis, Livi, Roberto, Goetz, Keith, Larson, Davin, Malaspina, David, Morgan, Huw, Narock, Ayris, Schwadron, Nathan, Bonnell, John, Harvey, Peter, Wygant, John   +28 more
openaire   +2 more sources

Predicting Geomagnetic Activity Cycles

Space Weather, Volume 23, Issue 5, May 2025.
Abstract The vast majority of solar cycle predictions focus on predicting the 11‐year sunspot cycle, while space weather and geomagnetic activity predictions are largely made for short time scales, from hours up to a month. Here, we aim to predict geomagnetic activity in the solar cycle time scale. We use a 180‐year composite of the geomagnetic aa $aa$
Timo Qvick, Timo Asikainen, Kalevi Mursula   +2 more
wiley   +1 more source

Investigating the Behavior and Spatiotemporal Variations of Green-line Emission in the Solar Corona

The Astrophysical Journal Supplement Series
Understanding coronal structure and dynamics can be facilitated by analyzing green-line emission, which enables the investigation of diverse coronal structures such as coronal loops, streamers, coronal holes, and various eruptions in the solar atmosphere.
Jacob Oloketuyi, Yu Liu, Linhua Deng, Abouazza Elmhamdi, Fengrong Zhu, Ayodeji Ibitoye, Opeyemi Omole, Feiyang Sha, Qiang Liu   +8 more
doaj   +1 more source