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Related papers: Propagating MHD waves in coronal holes

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Coronal holes (CH) are regions of open magnetic field lines in the solar corona and the source of fast solar wind. Understanding the evolution of coronal holes is critical for solar magnetism as well as for accurate space weather forecasts.…

Space Physics · Physics 2018-05-02 Amr Hamada , Timo Asikainen , Ilpo Virtanen , Kalevi Mursula

Waves are thought to play a significant role in the heating of the solar atmosphere and the acceleration of the wind. Among the many types of waves observed in the Sun, the so-called p-modes with a 3 mHz frequency peak dominate the lower…

An empirical model for forecasting solar wind speed related geomagnetic events is presented here. The model is based on the estimated location and size of solar coronal holes. This method differs from models that are based on photospheric…

Astrophysics · Physics 2008-11-26 S. Robbins , C. J. Henney , J. W. Harvey

The solar atmosphere shows anomalous variation in temperature, starting from the 5500 K photosphere to the million-degree Kelvin corona. The corona itself expands into the interstellar medium as the free streaming solar wind, which…

Solar and Stellar Astrophysics · Physics 2023-04-05 Vishal Upendran

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

A set of 23 observations of coronal jet events that occurred in coronal bright points has been analyzed. The focus was on the temporal evolution of the mean brightness before and during coronal jet events. In the absolute majority of the…

We present EIS/Hinode & SUMER/SoHO joint observations allowing the first spectroscopic detection of accelerating disturbances as recorded with coronal lines in inter-plume and plume regions of a polar coronal hole. From time-distance…

Solar and Stellar Astrophysics · Physics 2010-06-28 G. R. Gupta , D. Banerjee , L. Teriaca , S. Imada , S. Solanki

The solar magnetic field is the primary agent that drives solar activity and couples the Sun to the Heliosphere. Although the details of this coupling depend on the quantitative properties of the field, many important aspects of the corona…

Astrophysics · Physics 2009-11-13 S. K. Antiochos , C. R. DeVore , J. T. Karpen , Z. Mikic

We present a further investigation into the increased ionization observed in element charge states in the fast solar wind compared to its coronal hole source regions. Once ions begin to be perpendicularly heated by ion cyclotron waves and…

Astrophysics · Physics 2011-02-11 J. Martin Laming , Susan T. Lepri

In-situ measurements by several spacecraft have revealed that the solar wind is frequently perturbed by transient structures (magnetic folds, jets, waves, flux-ropes) that propagate rapidly away from the Sun over large distances. Parker…

Solar and Stellar Astrophysics · Physics 2021-09-15 R. F. Pinto , N. Poirier , A. P. Rouillard , A. Kouloumvakos , L. Griton , N. Fargette , R. Kieokaew , B. Lavraud , A. S. Brun

High speed solar wind streams (HSSs) are very efficient drivers of geomagnetic activity at high latitudes. In this paper we use a recently developed $\Delta{H}$ parameter of geomagnetic activity, calculated from the night-side hourly…

Space Physics · Physics 2017-05-03 Renata Lukianova , Lauri Holappa , Kalevi Mursula

Coronal holes (CHs) are regions of open magnetic flux which are the source of high speed solar wind (HSSW) streams. To date, it is not clear which aspects of CHs are of most influence on the properties of the solar wind as it expands…

Solar and Stellar Astrophysics · Physics 2018-12-12 Tadhg M. Garton , Sophie A. Murray , Peter T. Gallagher

We have measured the widths of spectral lines from a polar coronal hole using the Extreme Ultraviolet Imaging Spectrometer onboard Hinode. Polar coronal holes are regions of open magnetic field and the source of the fast solar wind. We find…

Solar and Stellar Astrophysics · Physics 2015-06-04 Michael Hahn , Enrico Landi , Daniel Wolf Savin

We show that the coronal heating and the fast solar wind acceleration in the coronal holes are natural consequence of the footpoint fluctuations of the magnetic fields at the photosphere, by performing one-dimensional magnetohydrodynamical…

Astrophysics · Physics 2009-11-11 Takeru K. Suzuki , Shu-ichiro Inutsuka

Coronal holes (CHs) are magnetically open regions that allow hot coronal plasma to escape from the Sun and form the high-speed solar wind. This wind can interact with Earth's magnetic field. For this reason, developing an accurate…

Solar and Stellar Astrophysics · Physics 2025-09-16 Jeremy A. Grajeda , Laura E. Boucheron , Michael S. Kirk , Andrew Leisner , C. Nick Arge , Jaime A. Landeros

The details of the mechanism(s) responsible for the observed heating and dynamics of the solar atmosphere still remain a mystery. Magnetohydrodynamic (MHD) waves are thought to play a vital role in this process. Although it has been shown…

Solar and Stellar Astrophysics · Physics 2013-06-19 R. J. Morton , G. Verth , D. B. Jess , D. Kuridze , M. S. Ruderman , M. Mathioudakis , R. Erdelyi

Spicules are thin, elongated jet-like features seen in observations of the solar atmosphere, at the interface between the solar photosphere and the corona. These features exhibit highly complex dynamics and are a necessary connecting link…

Solar and Stellar Astrophysics · Physics 2025-08-04 Sankalp Srivastava , Piyali Chatterjee , Sahel Dey , Robertus Erdélyi

Coronal hole boundaries are the interfaces between closed and open magnetic field regions in the solar atmosphere. Many fundamental processes take place at these regions, including magnetic reconnection that is responsible for solar wind…

The solar surface and atmosphere are highly dynamic plasma environments, which evolve over a wide range of temporal and spatial scales. Large-scale eruptions, such as coronal mass ejections, can be accelerated to millions of kilometres per…

The high-speed solar wind is typically the simplest and least stochastic type of large-scale plasma flow in the heliosphere. For much of the solar cycle, it is connected magnetically to large polar coronal holes on the Sun's surface.…

Solar and Stellar Astrophysics · Physics 2020-12-22 Steven R. Cranmer