Results 21 to 30 of about 18,173,480 (298)

Simulations of facular magnetic fields on cool stars

Astronomy & Astrophysics
Context. Stellar convection in the presence of magnetic field affects the emergent intensity, as well as the structure and evolution of cool main-sequence dwarfs. Aims.
Singh Bhatia Tanayveer, Cameron Robert H., Solanki Sami K., Przybylski Damien F., Witzke Veronika, Shapiro Alexander, Kostogryz Nadiia   +6 more
doaj   +1 more source

In Situ Optimized Substrate Witness Plates: Ground Truth for Key Processes on the Moon and Other Planets

Earth and Space Science, 2023
Future exploration efforts of the Moon, Mars, and other bodies are poised to focus heavily on persistent and sustainable survey and research efforts, especially given the recent interest in a long‐term sustainable human presence at the Moon. Key to these
Prabal Saxena, Liam S. Morrissey, Rosemary M. Killen, Jason L. McLain, Li Hsia Yeo, Natalie M. Curran, Nithin S. Abraham, Heather V. Graham, Orenthal J. Tucker, Menelaos Sarantos, Aaron B. Regberg, Diane E. Pugel, Andrew W. Needham, Mark Hasegawa, Alfred J. Wong   +14 more
doaj   +1 more source

High-resolution observations of small-scale activity in coronal hole plumes

Astronomy & Astrophysics
Context. Largely radial ray-like structures, termed plumes, are often observed in coronal holes. Plumes have been proposed to channel magnetohydrodynamic (MHD) waves and the solar wind into the heliosphere.
Huang Ziwen, Chitta L. P., Teriaca L., Aznar Cuadrado R., Peter H., Solanki S. K., Wiegelmann T., Plaschke F.   +7 more
doaj   +1 more source

Solar sailing : mission applications and engineering challenges [PDF]

, 2003
Solar sailing is emerging as a promising form of advanced spacecraft propulsion, which can enable exciting new space-science mission concepts. By exploiting the momentum transported by solar photons, solar sails can perform high-energy orbittransfer ...
McInnes, Colin R.
core   +5 more sources

Ca II λ854.2 nm in an enhanced network region simulated with MURaM-ChE

Astronomy & Astrophysics
Context. The Ca IIλ854.2 nm line is widely used to study the chromosphere of the Sun. In the quiet Sun, the spatially averaged line profile shows a red asymmetry and a redshift of the line center. It is known that the effect of isotopic splitting must be
Ondratschek P. A., Przybylski D., Smitha H. N., Cameron R. H., Solanki S. K.   +4 more
doaj   +1 more source

Predictions of the geomagnetic secular variation based on the ensemble sequential assimilation of geomagnetic field models by dynamo simulations

Earth, Planets and Space, 2020
The IGRF offers an important incentive for testing algorithms predicting the Earth’s magnetic field changes, known as secular variation (SV), in a 5-year range. Here, we present a SV candidate model for the 13th IGRF that stems from a sequential ensemble
Sabrina Sanchez, Johannes Wicht, Julien Bärenzung   +2 more
doaj   +1 more source

Statistical properties of spicules in MURaM-ChE

Astronomy & Astrophysics
Context. Numerical simulations of the solar chromosphere have progressed towards reproducing spicules, which are transient features observed at the solar limb using spectral lines such as Hα, Ca II H&K, or Mg II h&k. Two types of spicules, referred to as
Chandra Sanghita, Cameron Robert, Przybylski Damien, Solanki Sami K.   +3 more
doaj   +1 more source

Formation and dynamics of a solar eruptive flux tube

Nature Communications, 2018
Solar eruptions are large explosions occurring in the solar atmosphere. Here, the authors perform magnetohydrodynamic simulations to unveil the dynamics of a solar eruption, and find that these are dominated by nonlinear processes involving flux tube ...
Satoshi Inoue, Kanya Kusano, Jörg Büchner, Jan Skála   +3 more
doaj   +1 more source

A simple stochastic model for dipole moment fluctuations in numerical dynamo simulations

Frontiers in Earth Science, 2016
Earth's axial dipole field changes in a complex fashion on many differenttime scales ranging from less than a year to tens of million years.Documenting, analysing, and replicating this intricate signalis a challenge for data acquisition, theoretical ...
Domenico G. eMeduri, Johannes eWicht
doaj   +1 more source

Author's Reply to Comment by Greaves et al. on “Phosphine in the Venusian Atmosphere: A Strict Upper Limit From SOFIA GREAT Observations”

Geophysical Research Letters, 2023
In an attempt to understand the findings presented in the Comment by Greaves et al. (2023, https://doi.org/10.1029/2023GL103539), we followed their data analysis methodology, omitting the hot and cold‐load calibrations that are an important part of the ...
M. A. Cordiner, H. Wiesemeyer, G. L. Villanueva, I. dePater, J. Stutzki, G. Liuzzi, R. Aladro, S. B. Charnley, R. Cosentino, S. Faggi, V. Kofman, B. A. McGuire, S. N. Milam, A. Moullet, C. A. Nixon, A. E. Thelen   +15 more
doaj   +1 more source