The structure and dynamics of the sun from helioseismology, and the neutrino problem

2008 ◽  
pp. 1-24
Author(s):  
Lucio Paternò
Keyword(s):  
The Sun ◽  
Structure And Dynamics

Global circulation of Mars’ upper atmosphere

Science ◽  
2019 ◽  
Vol 366 (6471) ◽  
pp. 1363-1366 ◽  
Author(s):  
M. Benna ◽  
S. W. Bougher ◽  
Y. Lee ◽  
K. J. Roeten ◽  
E. Yiğit ◽  
...  
Keyword(s):  
Gravity Waves ◽  
Incident Energy ◽  
Upper Atmosphere ◽  
The Sun ◽  
Mars Atmosphere ◽  
Neutral Winds ◽  
Global Circulation ◽  
Structure And Dynamics ◽  
Circulation Patterns

The thermosphere of Mars is the interface through which the planet is continuously losing its reservoir of atmospheric volatiles to space. The structure and dynamics of the thermosphere is driven by a global circulation that redistributes the incident energy from the Sun. We report mapping of the global circulation in the thermosphere of Mars with the Mars Atmosphere and Volatile Evolution (MAVEN) spacecraft. The measured neutral winds reveal circulation patterns simpler than those of Earth that persist over changing seasons. The winds exhibit pronounced correlation with the underlying topography owing to orographic gravity waves.

scholarly journals New Observational Aspects

1990 ◽  
Vol 138 ◽  
pp. 469-487
Author(s):  
Oddbj⊘rn Engvold
Keyword(s):  
High Resolution ◽  
Canary Islands ◽  
Solar Physics ◽  
High Resolution Imaging ◽  
The Sun ◽  
Image Stabilization ◽  
Structure And Dynamics ◽  
Solar Observations ◽  
Methods And Techniques ◽  
Resolution Imaging

The requirements and conditions for high resolution imaging and polarimetry of the Sun are reviewed. Various methods and techniques are discussed for image stabilization and sharpening in solar observations. The new solar facilities in the Canary Islands in particular are frequently reaching diffraction limited resolution and yield new insight in the structure and dynamics of the solar atmosphere. Future ground based telescopes like THEMIS and LEST, as well as planned solar missions in space will trigger a next advance in solar physics.

scholarly journals The future of helioseismology

2009 ◽  
Vol 5 (H15) ◽  
pp. 352-353
Author(s):  
Alexander G. Kosovichev
Keyword(s):  
Solar Cycle ◽  
Physical Properties ◽  
Active Regions ◽  
Magnetic Activity ◽  
Solar Dynamo ◽  
Current Status ◽  
The Sun ◽  
Interior Structure ◽  
Structure And Dynamics ◽  
Solar Magnetic Activity

AbstractHelioseismology has provided us with the unique knowledge of the interior structure and dynamics of the Sun, and the variations with the solar cycle. However, the basic mechanisms of solar magnetic activity, formation of sunspots and active regions are still unknown. Determining the physical properties of the solar dynamo, detecting emerging active regions and observing the subsurface dynamics of sunspots are among the most important and challenging problems. The current status and perspectives of helioseismology are briefly discussed.

Largescale Problems of Galactic Structure and Dynamics

1984 ◽  
Vol 88 ◽  
pp. 223-229
Author(s):  
K.C. Freeman
Keyword(s):  
Dark Matter ◽  
Classical Problem ◽  
Galactic Structure ◽  
Matter Density ◽  
Radial Velocities ◽  
The Other ◽  
The Sun ◽  
Structure And Dynamics ◽  
F Stars ◽  
Total Matter

In tills review, I will talk about some galactic problems for which stellar radial velocities are important. I will not attempt to be comprehensive, but will just pick out some problems which are being actively studied and which I find particularly interesting.This is a classical problem. The aim is to estimate the total matter density near the Sun from the distribution and kinematics of a tracer population towards the galactic poles. Recently Bahcall (1984a,b,c) has made a major attack on this problem, using F stars and W giants. He finds that about half the total matter density near the Sun is unaccounted for. This is important. We know from work on other diek galaxies that about half their mass lies in a dark corona and the other half in the disk; the nature of this dark matter is not yet understood. If we also see that about half the mass of the disk itself is dark, then that is certainly worth knowing, because this dark matter has dissipated to the disk. That may help us to understand the nature of the dark matter.

scholarly journals [no title]

1977 ◽  
Vol 4 (2) ◽  
pp. 223-239 ◽  
Author(s):  
J. Harvey
Keyword(s):  
Magnetic Field ◽  
Magnetic Fields ◽  
Spatial Resolution ◽  
Small Scale ◽  
Solar Photosphere ◽  
The Sun ◽  
Solar Magnetic Fields ◽  
Structure And Dynamics ◽  
Physical Problems ◽  
Observational Techniques

If the Sun is observed like a star, without spatial resolution, its magnetic field seldom exceeds 1 Gauss. But with high spatial resolution the field is seen to be largely concentrated into kG structures. Observations of the structure and dynamics of solar magnetic fields can therefore provide a guide to the nature of magnetic fields of other stars which cannot be resolved. Solar activity and the structure of the chromosphere and inner corona are intimately linked with magnetism and a complete understanding of these features often depends on magnetic field details. There are unsolved physical problems involving solar magnetic fields which have challenged many physicists. For example, confinement of small-scale fields in kG structures is a problem of current interest (Parker, 1976; Piddington, 1976; Spruit, 1976). Solar observers are no less challenged since the Sun presents us with a complicated magnetic field having a range of scales from global to less than the scale of our best observations as illustrated in Figures 1, 2, and 3. This paper is a survey of observational techniques and results at the small-scale end of the spectrum of sizes in the solar photosphere. This topic has been frequently reviewed (e.g. Athay, 1976; Beckers, 1976; Deubner, 1975; Howard, 1972; Mullan, 1974; Severny, 1972; Stenflo, 1975) so that recent work is emphasized here.

scholarly journals COMMISSION 12: SOLAR RADIATION AND STRUCTURE

2015 ◽  
Vol 11 (T29A) ◽  
pp. 278-299
Author(s):  
Gianna Cauzzi ◽  
Nataliya Shchukina ◽  
Alexander Kosovichev ◽  
Michele Bianda ◽  
Axel Brandenburg ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Internal Structure ◽  
Solar Atmosphere ◽  
The Sun ◽  
International Astronomical Union ◽  
Magnetic Structures ◽  
Structure And Dynamics ◽  
International Astronomical ◽  
Magnetic Network

Commission 12 of the International Astronomical Union encompasses investigations of the internal structure and dynamics of the Sun, the quiet solar atmosphere, solar radiation and its variability, and the nature of relatively stable magnetic structures like sunspots, faculae and the magnetic network. The Commission sees participation of over 300 scientists worldwide.

Helioseismic Inferences on the Internal Structure and Dynamics of the Sun

2019 ◽  
pp. 87-125
Author(s):  
Sarbani Basu ◽  
William J. Chaplin
Keyword(s):  
Internal Structure ◽  
The Sun ◽  
Structure And Dynamics

scholarly journals COMMISSION 12: SOLAR RADIATION AND STRUCTURE

2008 ◽  
Vol 4 (T27A) ◽  
pp. 104-123
Author(s):  
Valentin Martínez Pillet ◽  
Alexander Kosovichev ◽  
John T. Mariska ◽  
Thomas J. Bogdan ◽  
Martin Asplund ◽  
...  
Keyword(s):  
Solar Radiation ◽  
Internal Structure ◽  
Solar Atmosphere ◽  
The Sun ◽  
Magnetic Structures ◽  
Structure And Dynamics ◽  
In Parenthesis ◽  
Magnetic Network ◽  
Made In

Commission 12 encompasses investigations on the internal structure and dynamics of the Sun, mostly accessible through the techniques of local and global helioseismology, the quiet solar atmosphere, solar radiation and its variability, and the nature of relatively stable magnetic structures like sunspots, faculae and the magnetic network. A revision of the progress made in these fields is presented. For some specific topics, the review has counted with the help of experts outside the Commission Organizing Committee that are leading and/or have recently presented relevant works in the respective fields. In this cases the contributor's name is given in parenthesis.

Models of Structure and Dynamics of Prominences

1979 ◽  
Vol 44 ◽  
pp. 322-330 ◽  
Author(s):  
U. Anzer
Keyword(s):  
Magnetic Field ◽  
Cross Sections ◽  
Theoretical Models ◽  
Opposite Polarity ◽  
The Sun ◽  
Structure And Dynamics ◽  
Common Basis ◽  
Field Lines ◽  
Physical Phenomena ◽  
Helical Field

The discussion in Working Group1was centered around 3 theoretical models. The participants were well aware of the fact that these idealized models have only limited value towards our goal of understanding the complex physical phenomena of quiescent prominences. We used these models mainly as a common basis for our discussion. The models, shown in Figure 1 are all 2-dimensional and only cross-sections normal to the long axis of the prominence are drawn. They are based on different magnetic field configurations. In all 3 models currents flow inside the prominence giving rise to a Lorentz-force which keeps the material from falling freely towards the surface of the Sun. Due to horizontal motion parallel to the prominence of the foot points of opposite polarity a magnetic field normal to the plane drawn will be induced. This then implies additional currents in the corona surrounding the prominence. Note that those field lines in the Kuperus and Raadu model which are open cannot maintain any shear and therefore must lie in the plane. The circular lines in the model of Malville result from a projection of helical field structures.

Sign in / Sign up

Export Citation Format

Share Document