Results 91 to 100 of about 15,079 (225)

Chromospheric Evershed flow [PDF]

Astronomy & Astrophysics, 2003
We studied the chromospheric Evershed flow from filtergrams obtained at nine wavelengths along the Hα profile. We computed line-of-sight velocities based on Becker's cloud model and we determined the components of the flow velocity vector as a function of distance from the center of the sunspot, assuming an axial symmetry of both the spot and the flow.
Georgakilas, A. A., Christopoulou, E. B., Skodras, A., Koutchmy, S.   +3 more
openaire   +2 more sources

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

On the observability of T Tauri accretion shocks in the X-ray band

, 2010
Context. High resolution X-ray observations of classical T Tauri stars (CTTSs) show a soft X-ray excess due to high density plasma (n_e=10^11-10^13 cm^-3).
A. Maggio, Anders, Ardila, Argiroffi, Argiroffi, Argiroffi, Bary, Borkowski, Brickhouse, Brown, C. Argiroffi, Calvet, Colella, Cowie, Dalton, Dopita, Drake, Edwards, F. Reale, Fryxell, G. G. Sacco, G. Peres, Gullbring, Gullbring, Güdel, Günther, Günther, Günther, Herczeg, Huenemoerder, Johns-Krull, Kashyap, Kastner, Kastner, Koenigl, Koldoba, Lamzin, MacNeice, Martin, Mignone, Orlando, Orlando, Peres, R. L. Curran, Robrade, Romanova, S. Orlando, Sacco, Safier, Schmitt, Smith, Sutherland, Sutherland, Sutherland, Telleschi, Testa, Vernazza   +56 more
core   +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

On the Origin of the Slow Speed Solar Wind: Helium Abundance Variations

, 2012
The First Ionization Potential (FIP) effect is the by now well known enhancement in abundance over photospheric values of Fe and other elements with first ionization potential below about 10 eV observed in the solar corona and slow speed solar wind.
Antiochos, Avrett, Bourouaine, Bruno, Bryans, Byhring, Campos, Cara E. Rakowski, Cranmer, Cranmer, Feldman, Heggland, J. Martin Laming, Kasper, Kigure, Killie, Ko, Laming, Laming, Laming, Laming, Laming, Litwin, Longcope, Noci, Ofman, Ofman, Parker, Parker, Rappazzo, Rappazzo, Ruderman, Schwadron, Sturrock, Verdini, Wang, Wang, Wood   +37 more
core   +1 more source

On the solar chromosphere observed at the limb with Hinode

, 2010
Broad-band images in the Ca II H line, from the BFI instrument on the Hinode spacecraft, show emission from spicules emerging from and visible right down to the observed limb.
Carlsson, Mats, Judge, Philip G.
core   +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

The chromosphere and prominence magnetometer

, 2012
The Chromosphere and Prominence Magnetometer (ChroMag) is conceived with the goal of quantifying the intertwined dynamics and magnetism of the solar chromosphere and in prominences through imaging spectro-polarimetry of the full solar disk.
Bethge, Christian, de Wijn, Alfred G., McIntosh, Scott, Tomczyk, Steven   +3 more
core   +1 more source

Chromospheric dynamics [PDF]

Symposium - International Astronomical Union, 1996
This brief review advertises a breakthrough in solar dynamics: the identification of chromospheric Ca II K2V “grains” as manifestations of acoustic shocks. The successful numerical reproduction of the intricate spectral characteristics of K2V grain formation by Carlsson & Stein shows that the non-magnetic solar chromosphere is pervaded by outward ...
openaire   +2 more sources

NOAA's National Centers for Environmental Information Space Weather Data Inventory Status

Space Weather, Volume 23, Issue 7, July 2025.
Abstract We present here an updated overview of the Space Weather data curated and/or generated, improved, archived, and disseminated by the Solar Terrestrial Physics (STP) Section of the National Centers for Environmental Information (NCEI) in the National Oceanic and Atmospheric Administration (NOAA).
Alessandra Abe Pacini, Laurel Rachmeler, Kimberly Baugh   +2 more
wiley   +1 more source