English
Related papers

Related papers: Solar Atmosphere Radiative Transfer Model Comparis…

200 papers

The solar wind speed plays a key role in the transport of CME out of the Sun and ultimately determines the arrival time of CME-driven shocks in the heliosphere. Here, we develop an empirical model of the solar wind parameters at the inner…

Solar and Stellar Astrophysics · Physics 2018-10-04 Chin-Chun Wu , Kan Liou , Simon Plunkett , Dennis Socker , Y. M. Wang , Brian Wood , S. T. Wu , Murray Dryer , Christopher Kung

We analyze intermediate degree p-mode eigenfrequencies measured by GONG and MDI/SOHO over a solar cycle to study the source of their variability. We carry out a correlation analysis between the change in frequencies and several measures of…

Solar and Stellar Astrophysics · Physics 2011-02-11 Kiran Jain , S. C. Tripathy , F. Hill

We describe the Stagger Code for simulations of magneto-hydrodynamic (MHD) systems. This is a modular code with a variety of physics modules that will let the user run simulations of deep stellar atmospheres, sunspot formation, stellar…

Instrumentation and Methods for Astrophysics · Physics 2024-05-07 Robert F. Stein , Åke Nordlund , Remo Collet , Regner Trampedach

We present a new version of the MURaM radiative MHD code that allows for simulations spanning from the upper convection zone into the solar corona. We implemented the relevant coronal physics in terms of optically thin radiative loss, field…

Solar and Stellar Astrophysics · Physics 2016-12-28 Matthias Rempel

The solar brightness varies on timescales from minutes to decades. Determining the sources of such variations, often referred to as solar noise, is of importance for multiple reasons: a) it is the background that limits the detection of…

Solar and Stellar Astrophysics · Physics 2017-11-28 A. I. Shapiro , S. K. Solanki , N. A. Krivova , R. H. Cameron , K. L. Yeo , W. K. Schmutz

We have simulated the formation of a massive galaxy cluster (M$_{200}^{\rm crit}$ = 1.1$\times$10$^{15}h^{-1}M_{\odot}$) in a $\Lambda$CDM universe using 10 different codes (RAMSES, 2 incarnations of AREPO and 7 of GADGET), modeling…

Global magnetohydrodynamic (MHD) models play an important role in the infrastructure of space weather forecasting. Validating such models commonly utilizes in situ solar wind measurements made near the orbit of the Earth. The purpose of…

Solar and Stellar Astrophysics · Physics 2024-10-31 Chin-Chun Wu , Kan Liou , Brian E. Wood , Y. M. Wang

We present a detailed comparison between simulations and seeing-free observations that takes into account the crucial influence of instrumental image degradation. We use images of quiet Sun granulation taken in the blue, green and red…

Solar and Stellar Astrophysics · Physics 2015-05-13 Sven Wedemeyer-Böhm , Luc Rouppe van der Voort

Context. Stellar spectral variability on timescales of a day and longer, arising from magnetic surface features such as dark spots and bright faculae, is an important noise source when characterising extra-solar planets. Current 1D models…

Solar and Stellar Astrophysics · Physics 2017-09-06 Charlotte M. Norris , Benjamin Beeck , Yvonne C. Unruh , Sami K. Solanki , Natalie A. Krivova , Kok Leng Yeo

A high-precision two-dimensional stellar evolution code has been developed for studying solar variability due to structural changes produced by varying internal magnetic fields of arbitrary configurations. Specifically, we are interested in…

Astrophysics · Physics 2009-11-11 L. H. Li , P. Ventura , S. Basu , S. Sofia , P. Demarque

The solar chromosphere is weakly ionized and interactions between ionized particles and neutral particles likely have significant consequences for the thermodynamics of the plasma. We investigate the importance of introducing neutral…

Solar and Stellar Astrophysics · Physics 2015-06-04 Juan Martinez-Sykora , Bart De Pontieu , Viggo Hansteen

We present results of non-LTE modeling of H-alpha 6563 A and Mg II k&h 2796 A and 2803 A lines. This modeling is important for interpretation of coordinated observations from the recently launched NASA's IRIS mission and from the New Solar…

Solar and Stellar Astrophysics · Physics 2014-12-02 Viacheslav M. Sadykov , Alexander G. Kosovichev

The solar brightness varies on timescales from minutes to decades. A clear identification of the physical processes behind such variations is needed for developing and improving physics-based models of solar brightness variability and…

Solar and Stellar Astrophysics · Physics 2015-09-30 A. I. Shapiro , S. K. Solanki , N. A. Krivova , R. V. Tagirov , W. K. Schmutz

Long-term trends in the solar spectral irradiance are important to determine the impact on Earth's climate. These long-term changes are thought to be caused mainly by changes in the surface area covered by small-scale magnetic elements. The…

Solar and Stellar Astrophysics · Physics 2015-05-14 N. Afram , Y. C. Unruh , S. K. Solanki , M. Schuessler , S. K. Mathew

Context. The variability of Solar Spectral Irradiance over the rotational period and its trend over the solar activity cycle are important for understanding the Sun-Earth connection as well as for observational constraints for solar models.…

Solar and Stellar Astrophysics · Physics 2015-06-16 C. Wehrli , W. Schmutz , A. I. Shapiro

The correlation between solar irradiance and the 11-year solar activity cycle is evident in the body of measurements made from space, which extend over the past four decades. Models relating variation in solar irradiance to photospheric…

Solar and Stellar Astrophysics · Physics 2015-07-07 K. L. Yeo , N. A. Krivova , S. K. Solanki

Electric currents play an important role in the energy balance of the plasma in the solar atmosphere. They are also indicative of non-potential magnetic fields and magnetic reconnection. Unfortunately, the direct measuring of electric…

Solar and Stellar Astrophysics · Physics 2023-01-25 J. M. Borrero , A. Pastor Yabar

Recent in-situ observations and numerical models indicated various types of magnetohydrodynamic (MHD) waves contributing to the solar wind acceleration. Among them is an MHD wave decomposition at distances closer than 50 $R_{\odot}$ using…

Solar and Stellar Astrophysics · Physics 2025-03-19 Shota Chiba , Munehito Shoda , Takeshi Imamura

Quasi-periodic propagating intensity disturbances have been observed in large coronal loops in EUV images over a decade, and are widely accepted to be slow magnetosonic waves. However, spectroscopic observations from Hinode/EIS revealed…

Solar and Stellar Astrophysics · Physics 2015-11-04 X. Fang , D. Yuan , T. Van Doorsselaere , R. Keppens , C. Xia

The solar atmosphere is known to contain many different types of wavelike oscillation. Waves and other fluctuations (e.g., turbulent eddies) are believed to be responsible for at least some of the energy transport and dissipation that heats…

Solar and Stellar Astrophysics · Physics 2023-08-09 Steven R. Cranmer , Momchil E. Molnar
‹ Prev 1 8 9 10 Next ›