scholarly journals A Wake-up Call from the Sun

Eos ◽  
2017 ◽  
Vol 98 ◽  
Author(s):  
Michael Hapgood

A sudden burst of activity from the Sun in early September 2017 caused a wide range of space weather effects at Earth.

2019 ◽  
Vol 6 (1) ◽  
pp. 1-13
Author(s):  
Ashish Mishra ◽  
Mukul Kumar

The present article is the successor of Solar Dynamical Processes I. The previous article was focused on the Sun, its magnetic field with an emphasis on various dynamical processes occurring on the Sun, e.g. sunspots, prominence and bright points which in turn plays a fundamental role in regulating the space weather. This article is emphasized on the solar dynamical processes and develop an extensive understanding of the various phenomena involved in their origin. The article also covers various models and hypothesis put forward by pioneer scientists on the basis of their observation by space-borne and ground-based instruments. This article shade light over a wide range of dynamical processes e.g., solar flares, coronal mass ejections, solar jets and coronal holes. Solar jets, the small-scale transient activities are found to have association with the other transient activities (e.g., mini-flares and mini-filaments). Flares as well as the coronal mass ejections are responsible for releasing a large amount of high energy charged particles and magnetic flux into the interplanetary space, and are being considered as the main drivers of space weather.


2002 ◽  
Vol 10 (2) ◽  
pp. 249-261
Author(s):  
ALEXI GLOVER ◽  
EAMONN DALY ◽  
ALAIN HILGERS ◽  
DAVID BERGHMANS

Space weather is caused by conditions on the Sun and in the solar wind, the magnetosphere, ionosphere and thermosphere that can influence the performance and reliability of space-borne and ground-based technological systems and can affect human life or health. It affects man-made systems such as satellite electronics, terrestrial power grids and radio communications. This paper provides an overview of how space weather arises in the solar–terrestrial system and how physical processes are able to cause space weather effects. We also discuss European perspectives and activities geared towards the possible initiation of a European Space Weather programme.


Author(s):  
David Fisher

There are eight columns in the Periodic Table. The eighth column is comprised of the rare gases, so-called because they are the rarest elements on earth. They are also called the inert or noble gases because, like nobility, they do no work. They are colorless, odorless, invisible gases which do not react with anything, and were thought to be unimportant until the early 1960s. Starting in that era, David Fisher has spent roughly fifty years doing research on these gases, publishing nearly a hundred papers in the scientific journals, applying them to problems in geophysics and cosmochemistry, and learning how other scientists have utilized them to change our ideas about the universe, the sun, and our own planet. Much Ado about (Practically) Nothing will cover this spectrum of ideas, interspersed with the author's own work which will serve to introduce each gas and the important work others have done with them. The rare gases have participated in a wide range of scientific advances-even revolutions-but no book has ever recorded the entire story. Fisher will range from the intricacies of the atomic nucleus and the tiniest of elementary particles, the neutrino, to the energy source of the stars; from the age of the earth to its future energies; from life on Mars to cancer here on earth. A whole panoply that has never before been told as an entity.


Space Weather ◽  
2016 ◽  
Vol 14 (5) ◽  
pp. 343-350 ◽  
Author(s):  
E. B. Clements ◽  
A. K. Carlton ◽  
C. J. Joyce ◽  
N. A. Schwadron ◽  
H. E. Spence ◽  
...  

2016 ◽  
Vol 34 (4) ◽  
pp. 427-436 ◽  
Author(s):  
Larisa Trichtchenko

Abstract. Power transmission lines above the ground, cables and pipelines in the ground and under the sea, and in general all man-made long grounded conductors are exposed to the variations of the natural electromagnetic field. The resulting currents in the networks (commonly named geomagnetically induced currents, GIC), are produced by the conductive and/or inductive coupling and can compromise or even disrupt system operations and, in extreme cases, cause power blackouts, railway signalling mis-operation, or interfere with pipeline corrosion protection systems. To properly model the GIC in order to mitigate their impacts it is necessary to know the frequency dependence of the response of these systems to the geomagnetic variations which naturally span a wide frequency range. For that, the general equations of the electromagnetic induction in a multi-layered infinitely long cylinder (representing cable, power line wire, rail or pipeline) embedded in uniform media have been solved utilising methods widely used in geophysics. The derived electromagnetic fields and currents include the effects of the electromagnetic properties of each layer and of the different types of the surrounding media. This exact solution then has been used to examine the electromagnetic response of particular samples of long conducting structures to the external electromagnetic wave for a wide range of frequencies. Because the exact solution has a rather complicated structure, simple approximate analytical formulas have been proposed, analysed and compared with the results from the exact model. These approximate formulas show good coincidence in the frequency range spanning from geomagnetic storms (less than mHz) to pulsations (mHz to Hz) to atmospherics (kHz) and above, and can be recommended for use in space weather applications.


2015 ◽  
Vol 11 (S320) ◽  
pp. 134-137
Author(s):  
John P. Pye ◽  
Simon R. Rosen

AbstractWe present estimates of cool-star X-ray flare rates determined from the XMM-Tycho survey (Pyeet al. 2015, A&A, 581, A28), and compare them with previously published values for the Sun and for other stellar EUV and white-light samples. We demonstrate the importance of applying appropriate corrections, especially in regard to the total, effective size of the stellar sample. Our results are broadly consistent with rates reported in the literature for Kepler white-light flares from solar-type stars, and with extrapolations of solar flare rates, indicating the potential of stellar X-ray flare observations to address issues such as ‘space weather’ in exoplanetary systems and our own solar system.


2016 ◽  
pp. 353-387
Author(s):  
Keith M. Groves ◽  
Charles S. Carrano

2020 ◽  
Vol 240 ◽  
pp. 07011
Author(s):  
Kushagra Shrivastava ◽  
Keith Wen Kai Chia ◽  
Kang Jun Wong ◽  
Alfred Yong Liang Tan ◽  
Hwee Tiang Ning

Solar activity research provides insight into the Sun’s past, future (Science Daily, 2018). The solar activity includes observations of large numbers of intense sunspots, flares, and other phenomena; and demands a wide range of techniques and measurements on the observations. This research needs long term data collection before critical analyses can occur, to generate meaningful learning and knowledge. In this project, we will use solar imaging to make observations of solar activity, and take our baby steps to make contributions in citizen science. Observations will be made in 3 wavelengths to gain a more thorough analysis by looking at different perspectives of the Sun, namely H-Alpha, Calcium-K, and white light.


2020 ◽  
Vol 642 ◽  
pp. A2 ◽  
Author(s):  
A. P. Rouillard ◽  
R. F. Pinto ◽  
A. Vourlidas ◽  
A. De Groof ◽  
W. T. Thompson ◽  
...  

Context. The Solar Orbiter spacecraft will be equipped with a wide range of remote-sensing (RS) and in situ (IS) instruments to record novel and unprecedented measurements of the solar atmosphere and the inner heliosphere. To take full advantage of these new datasets, tools and techniques must be developed to ease multi-instrument and multi-spacecraft studies. In particular the currently inaccessible low solar corona below two solar radii can only be observed remotely. Furthermore techniques must be used to retrieve coronal plasma properties in time and in three dimensional (3D) space. Solar Orbiter will run complex observation campaigns that provide interesting opportunities to maximise the likelihood of linking IS data to their source region near the Sun. Several RS instruments can be directed to specific targets situated on the solar disk just days before data acquisition. To compare IS and RS, data we must improve our understanding of how heliospheric probes magnetically connect to the solar disk. Aims. The aim of the present paper is to briefly review how the current modelling of the Sun and its atmosphere can support Solar Orbiter science. We describe the results of a community-led effort by European Space Agency’s Modelling and Data Analysis Working Group (MADAWG) to develop different models, tools, and techniques deemed necessary to test different theories for the physical processes that may occur in the solar plasma. The focus here is on the large scales and little is described with regards to kinetic processes. To exploit future IS and RS data fully, many techniques have been adapted to model the evolving 3D solar magneto-plasma from the solar interior to the solar wind. A particular focus in the paper is placed on techniques that can estimate how Solar Orbiter will connect magnetically through the complex coronal magnetic fields to various photospheric and coronal features in support of spacecraft operations and future scientific studies. Methods. Recent missions such as STEREO, provided great opportunities for RS, IS, and multi-spacecraft studies. We summarise the achievements and highlight the challenges faced during these investigations, many of which motivated the Solar Orbiter mission. We present the new tools and techniques developed by the MADAWG to support the science operations and the analysis of the data from the many instruments on Solar Orbiter. Results. This article reviews current modelling and tool developments that ease the comparison of model results with RS and IS data made available by current and upcoming missions. It also describes the modelling strategy to support the science operations and subsequent exploitation of Solar Orbiter data in order to maximise the scientific output of the mission. Conclusions. The on-going community effort presented in this paper has provided new models and tools necessary to support mission operations as well as the science exploitation of the Solar Orbiter data. The tools and techniques will no doubt evolve significantly as we refine our procedure and methodology during the first year of operations of this highly promising mission.


Sign in / Sign up

Export Citation Format

Share Document