Multi-Scale Physics in Coronal Heating and Solar Wind Acceleration

Multi-Scale Physics in Coronal Heating and Solar Wind Acceleration PDF Author: David Burgess
Publisher: Springer
ISBN: 9781461464617
Category : Science
Languages : en
Pages : 0

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Book Description
This volume explores the cross-linkages between the kinetic processes and macroscopic phenomena in the solar atmosphere, which are at the heart of our current understanding of the heating of the closed and open corona and the acceleration of the solar wind. The focus lies on novel data, on theoretical models that have observable consequences through remote sensing, and on near-solar and inner-heliosphere observations, such as anticipated by the upcoming Solar Orbiter and Solar Probe missions, which are currently developed by the international community. This volume is aimed at students and researchers active in solar physics and space science. Previously published in Space Science Reviews journal, Vol. 172, Nos. 1-4, 2012.

Multi-Scale Physics in Coronal Heating and Solar Wind Acceleration

Multi-Scale Physics in Coronal Heating and Solar Wind Acceleration PDF Author: David Burgess
Publisher: Springer
ISBN: 9781461464617
Category : Science
Languages : en
Pages : 0

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Book Description
This volume explores the cross-linkages between the kinetic processes and macroscopic phenomena in the solar atmosphere, which are at the heart of our current understanding of the heating of the closed and open corona and the acceleration of the solar wind. The focus lies on novel data, on theoretical models that have observable consequences through remote sensing, and on near-solar and inner-heliosphere observations, such as anticipated by the upcoming Solar Orbiter and Solar Probe missions, which are currently developed by the international community. This volume is aimed at students and researchers active in solar physics and space science. Previously published in Space Science Reviews journal, Vol. 172, Nos. 1-4, 2012.

Multi-scale Physics in Coronal Heating and Solar Wind Accelation

Multi-scale Physics in Coronal Heating and Solar Wind Accelation PDF Author: David Burgess
Publisher:
ISBN:
Category :
Languages : en
Pages : 409

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Book Description


Coronal Holes and Solar Wind Acceleration

Coronal Holes and Solar Wind Acceleration PDF Author: John L. Kohl
Publisher: Springer Science & Business Media
ISBN: 9401591679
Category : Science
Languages : en
Pages : 360

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Book Description
The SOHO-7 Workshop was held from 28 September through 1 October 1998 at the Asticou Inn in Northeast Harbor, Maine. The primary topic of this Workshop was the impact of SOHO observations on our understanding of the nature and evolution of coronal holes and the acceleration and composition of the solar wind. The presentations and discussions occasionally went beyond this topic to include the impact of the reported research on other solar structures and the heliosphere. SOHO (the Solar and Heliospheric Observatory), a project of international cooperation between ESA and NASA, was launched in December 1995 and began its science operations during the first few months of 1996. To many solar and space physicists, it was a great advantage that SOHO began itscomprehensive look at the Sun during the 1996 solar minimum. The qualitatively simple two-phase corona, with polar coronal holes expanding into the high-speed solar wind, and a steady equatorial streamer belt related somehow to the stochastic slow-speed solar wind, allowed various SOHO diagnostics to be initiated with a reasonably well understoodcircumsolar geometry. The analysis of subsequentSOHO measurements made during the rising phase of solar cycle 23 will continue to benefit from what has been learned from the first two years of data.

Physics of the Solar Corona

Physics of the Solar Corona PDF Author: Markus Aschwanden
Publisher: Springer Science & Business Media
ISBN: 9783540307655
Category : Science
Languages : en
Pages : 946

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Book Description
A thorough introduction to solar physics based on recent spacecraft observations. The author introduces the solar corona and sets it in the context of basic plasma physics before moving on to discuss plasma instabilities and plasma heating processes. The latest results on coronal heating and radiation are presented. Spectacular phenomena such as solar flares and coronal mass ejections are described in detail, together with their potential effects on the Earth.

Multiscale Coupling of Sun-Earth Processes

Multiscale Coupling of Sun-Earth Processes PDF Author: A.T.Y. Lui
Publisher: Elsevier
ISBN: 0444518819
Category : Science
Languages : en
Pages : 528

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Book Description
Full text e-book available as part of the Elsevier ScienceDirect Earth and Planetary Sciences subject collection.

Multi-Wavelength Observations of Coronal Structure and Dynamics

Multi-Wavelength Observations of Coronal Structure and Dynamics PDF Author: Penny Martens
Publisher: Elsevier
ISBN: 0080537170
Category : Science
Languages : en
Pages : 461

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Book Description
These are the Proceedings of the Yohkoh 10th Anniversary Meeting, a COSPAR Colloquium held in Kona, Hawaii, USA, on January 20-24, 2002. The title of the meeting was Multi-Wavelength Observations of Coronal Structure and Dynamics. In these proceedings the many and varied advances of the dynamics solar atmosphere in the past ten years of observations by Yohkoh have been reviewed.

Physics of the Solar Corona

Physics of the Solar Corona PDF Author: Constantin J. Macris
Publisher:
ISBN:
Category : Sun
Languages : en
Pages : 0

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Book Description


The Evolution of Modeled Coronal Mass Ejection in the Lower Corona

The Evolution of Modeled Coronal Mass Ejection in the Lower Corona PDF Author: Rebekah Minnel Evans Frolov
Publisher:
ISBN:
Category : Coronal mass ejections
Languages : en
Pages : 0

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Book Description
Coronal mass ejections (CMEs) and their associated shocks are major sources of space weather. In order to forecast their impact at Earth, it is crucial to accurately model their propagation in interplanetary space. The only tool capable of treating the large scales of CME evolution is global magnetohydrodynamics (MHD) modeling. However, this approach cannot resolve the small scales on which important processes occur (such as the acceleration of the solar wind and coronal heating). The solar wind solution depends on which method is utilized to mimic these processes. And because the evolution of a CME depends crucially on its interaction with the solar wind, the CME evolution will also be connected to the heating mechanisms and drivers utilized in an MHD model. In the first part of the thesis, we show that the ad hoc approaches to coronal heating used in global MHD models leads to unphysical conditions for CME-driven shock formation in the lower corona (1-10 solar radii). We present this argument in two steps. First, we present a CME simulation in which the solar wind was accelerated and heated by reducing the value of the polytropic index (to less than the adiabatic value) in the lower corona. As it is not well understood, we do not model the CME initiation process - we utilize an out-of-equilibrium Titov-Demoulin flux rope to begin the eruption. We analyze several aspects of the CME, such as its kinematics and energy evolution, the shock formation and evolution, the plasma flows in the CME-sheath and their connection to the CME magnetic field vector, and the plasma pile-up at the front of the CME. We find that some characteristics are inconsistent with the observed properties of CMEs, and we connect these to the ad hoc treatment of the solar wind heating. Second, we use data of CME shock-accelerated solar energetic particle events to constrain the profile of the Alfven speed in the lower corona. We show that the Alfven speed profile from global MHD models with ad hoc heating is not aligned with these observations, but that local (one dimensional) models with physically-motivated Alfven wave dissipation as a heating mechanism were in agreement. In the second part of the thesis, we study the resonant absorption of surface Alfven waves (SAW), a process which heats the solar wind. It is driven by a transverse gradient in the local Alfven speed (in relation to the magnetic field direction). In the solar corona, we expect this mechanism to occur at the boundaries of open and closed magnetic fields. We make the first estimation of SAW energy dissipation in the solar corona and find that it is comparable to the ad hoc heating a polytropic model at the boundary of open and closed magnetic fields and in subpolar open field regions. Next, we implemented the SAW damping mechanism into the new solar corona component of the Space Weather Modeling Framework, in which Alfven wave energy transport is self-consistently coupled to the MHD equations. The model already included wave dissipation along open magnetic field lines, mimicking turbulence. We demonstrate that including SAW dissipation in the model improved agreement with observations of coronal temperature both near the Sun and in the inner heliosphere by comparing with data from Ulysses and the Solar Terrestrial Relations Observatory (STEREO). Also, the inclusion of SAW dissipation steepened the Alfven speed profile in the lower corona, aligning the Alfven profile better with observational constraints of shock formation. In the final part of the thesis, we modeled a CME in this newly developed solar wind background, and studied the interaction between the CME and the wind. We generate the eruption with a flux rope. We constrain the parameters of the flux rope with data from the 13 May 2005 eruption, including H-alpha images of the pre-eruption magnetic field, coronagraph images of the CME's shape and velocity. Because the flux rope traveled faster than the local magnetosonic speed, it acted as a piston and drove a shock wave ahead of it. The CME-driven shock had a strong impact on the solar wind environment through which it propagates: it altered the wave energy by concentrating it in the sheath through advection, and also increasing its value through momentum transfer. This simulation demonstrated how Alfven waves are focused into the sheaths of ICMEs. The wave energy is then dissipated at the shock due to SAW damping. The shock heating accounted for 10% of the total change in thermal energy of the CME. The resulting temperature distribution of the CME is more aligned with observations than from a CME modeled in a polytropic solar wind. This thesis has improved our understanding of the interaction between a CME and the solar wind through which it propagates. Our picture of CME-evolution in the lower corona will be tested by future missions Solar Probe (which will sample this region directly) and the Solar Orbiter.

Coronal Expansion and Solar Wind

Coronal Expansion and Solar Wind PDF Author: A. J. Hundhausen
Publisher: Springer Science & Business Media
ISBN: 3642654142
Category : Science
Languages : en
Pages : 250

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Book Description
Little more than ten years have passed since spaceprobe-borne instruments con clusively demonstrated the existence of the solar wind. These observations con firmed the basic validity of a theoretical model, first proposed by E. N. Parker, predicting a continuous, rapid expansion of the solar corona. The subsequent decade has seen a tremendous growth in both the breadth and sophistication of solar wind observations; the properties of the interplanetary plasma near the orbit of the earth are now known in great detail. The theory of the coronal ex pansion has also been highly refilled both in the sense of including additional physical processes, and of treating more realistic (time-dependent and non spheri cally-symmetric) coronal boundary conditions. The present volume is an attempt to synthesize the solar wind observations and coronal expansion models from this decade of rapid development. The ultimate goal is, of course, the interpretation of observed solar wind phenomena as the effects of basic physical processes occurring in the coronal and interplanetary plasma and as the natural manifestations of solar properties and structures. This approach implies an emphasis upon the "large-scale" features revealed by the observations. It requires extensive use of the concepts and methods of fluid mechanics.

MHD Structures, Waves and Turbulence in the Solar Wind

MHD Structures, Waves and Turbulence in the Solar Wind PDF Author: C.-Y. Tu
Publisher: Springer Science & Business Media
ISBN: 9401585415
Category : Science
Languages : en
Pages : 214

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Book Description
This is the first book to give a comprehensive overview of recent observational and theoretical results on solar wind structures and fluctuations and magnetohydrodynamic waves and turbulence, preference being given to phenomena in the inner heliosphere. Emphasis is placed on the progress made in the past decade in the understanding of the nature and origin of especially small-scale, compressible and incompressible fluctuations. Turbulence models describing the spatial transport and spectral transfer of the fluctuations in the inner heliosphere are discussed. Intermittency of solar wind fluctuations and their statistical distributions are investigated. Studies of the heating and acceleration effects of the turbulence on the background wind are critically surveyed. Finally, open questions concerning the origin, nature and evolution of the fluctuations are listed, and perspectives for future research are outlined. The book is for graduate students and researchers in the field. Other target groups are scientists and professionals interested in space plasma physics and/or MHD turbulence.