scholarly journals Forbush effects and their connection with solar, interplanetary and geomagnetic phenomena

2008 ◽  
Vol 4 (S257) ◽  
pp. 439-450 ◽  
Author(s):  
A. V. Belov
Keyword(s):  
Solar Wind ◽  
Cosmic Rays ◽  
World Wide ◽  
Forbush Decrease ◽  
Relevant Information ◽  
The Sun ◽  
The World ◽  
Using Data ◽  
Active Processes ◽  
Forbush Effect

AbstractForbush decrease (or, in a broader sense, Forbush effect) - is a storm in cosmic rays, which is a part of heliospheric storm and very often observed simultaneously with a geomagnetic storm. Disturbances in the solar wind, magnetosphere and cosmic rays are closely interrelated and caused by the same active processes on the Sun. Thus, it is natural and useful to investigate them together. Such an investigation in the present work is based on the characteristics of cosmic rays with rigidity of 10 GV. The results are derived using data from the world wide neutron monitor network and are combined with relevant information into a data base on Forbush effects and large interplanetary disturbances.

ASYMMETRY IN THE RECOVERY FROM A VERY DEEP FORBUSH-TYPE DECREASE IN COSMIC-RAY INTENSITY

1961 ◽  
Vol 39 (2) ◽  
pp. 239-251 ◽  
Author(s):  
D. C. Rose ◽  
S. M. Lapointe
Keyword(s):  
Cosmic Rays ◽  
Local Time ◽  
Recovery Period ◽  
Forbush Decrease ◽  
Cosmic Ray ◽  
The Sun ◽  
Cosmic Ray Intensity ◽  
The Third ◽  
The World

The intensity–time curves for cosmic rays recorded at some 30 stations distributed all over the world are examined for structure in the recovery period from the third in a series of three closely spaced Forbush-type decreases which occurred in the middle of July 1959. It is shown that the structure of intensity peaks is regular and that these occur at each station at the same effective local time. It is found that this is consistent with the hypothesis that recovery from a very deep Forbush-type decrease is first apparent in directions making 15° and 165° with the sun–earth line respectively. The analyses suggest further, that during recovery from this deep Forbush decrease temporary openings appeared in the intensity depressing mechanism which allowed intensity increases in limited directions.

Cross-Lingual Information Retrieval

2005 ◽  
pp. 153-170 ◽  
Author(s):  
Christopher Yang ◽  
Kar W. Li
Keyword(s):  
Information Retrieval ◽  
Digital Library ◽  
Digital Libraries ◽  
World Wide ◽  
Relevant Information ◽  
Semantic Interoperability ◽  
Library Research ◽  
The World ◽  
Cross Lingual ◽  
Multiple Languages

Structural and semantic interoperability have been the focus of digital library research in the early 1990s. Many research works have been done on searching and retrieving objects across variations in protocols, formats, and disciplines. As the World Wide Web has become more popular in the last ten years, information is available in multiple languages in global digital libraries. Users are searching across the language boundary to identify the relevant information that may not be available in their own language. Cross-lingual semantic interoperability has become one of the focuses in digital library research in the late 1990s. In particular, research in cross-lingual information retrieval (CLIR) has been very active in recent conferences on information retrieval, digital libraries, knowledge management, and information systems. The major problem in CLIR is how to build the bridge between the representations of user queries and documents if they are of different languages.

Digital Resources for Mathematics Teachers

2017 ◽  
pp. 489-510
Author(s):  
Janine M. Viglietti ◽  
Deborah Moore-Russo
Keyword(s):  
Mathematics Education ◽  
World Wide Web ◽  
Mathematics Teachers ◽  
World Wide ◽  
Teacher Educators ◽  
Relevant Information ◽  
Habits Of Mind ◽  
Digital Resources ◽  
The World ◽  
Digital Landscape

With the increased push for digital resources in mathematics education, it is increasingly necessary to develop the skills needed to navigate the ever-changing digital landscape of the World Wide Web. The purpose of this chapter is three-fold. First, we help the reader develop a better understanding of the digital landscape through discussion of the contributors and contributions of the entities developing digital resources in the field of mathematics education. Second, we consider means to successfully navigate the digital landscape by developing a better understanding of the machinations of the tools that are commonly used to seek out digital resources. Finally, we consider ways the reader can become more intelligent consumers of digital resources. We synthesize knowledge of stakeholders, resources, and search tools to help teachers and teacher educators develop the habits of mind that will help them seek out quality resources and relevant information in much in the same way as researchers do.

A Report on a Novice User's Interaction with the Internet through a Self-Voicing Application

2005 ◽  
Vol 99 (1) ◽  
pp. 40-54 ◽  
Author(s):  
Keith S. Jones ◽  
J. Shawn Farris ◽  
Peter D. Elgin ◽  
Brent A. Anders ◽  
Brian R. Johnson
Keyword(s):  
World Wide ◽  
Protocol Analysis ◽  
Data Gathering ◽  
Relevant Information ◽  
The Internet ◽  
Verbal Protocol ◽  
Verbal Protocol Analysis ◽  
Textual Information ◽  
The World ◽  
The Individual

This study used verbal protocol analysis to examine the behavior of an individual with visual impairment using a self-voicing application to find information on the World Wide Web. The results indicated that executing actions (such as typing or pressing keys) and interpreting the computer system's state (data gathering) were the most frequent and time-consuming tasks. Furthermore, the individual had difficulty determining the effects of her actions on the system and whether relevant information was present on a page. These results suggest that there may be problems in interfacing the user with the software and the way textual information is aurally displayed to the user.

scholarly journals Cosmic Ray Evidence for the Magnetic Configuration of the Heliosphere

1981 ◽  
Vol 94 ◽  
pp. 397-398
Author(s):  
H. S. Ahluwalia
Keyword(s):  
Magnetic Field ◽  
Solar Wind ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Ground Level ◽  
The Sun ◽  
Ground Level Enhancement ◽  
Solar Cosmic Rays ◽  
Pile Up ◽  
Scattered Component

Sekido and Murakami (1958) proposed the existence of the heliosphere to explain the scattered component of the solar cosmic rays. The heliosphere of their conception is a spherical shell around the sun. The shell contains a highly-irregular magnetic field and serves to scatter the cosmic rays emitted by the sun. It thereby gives rise to an isotropic component of solar cosmic rays, following the maximum in the ground level enhancement (GLE). Meyer et al. (1956) showed that a similar picture applies to the GLE of 23 February 1956. They conclude that the inner and outer radii of the shell should be 1.4 AU and 5 AU respectively. They suggest that a shell is formed by the “pile-up” of the solar wind under pressure exerted by the interstellar magnetic field, as suggested by Davis (1955).

scholarly journals The Galactic cosmic ray intensity at the evolving Earth and young exoplanets

2020 ◽  
Author(s):  
Donna Rodgers-Lee ◽  
Aline Vidotto ◽  
Andrew Taylor ◽  
Paul Rimmer ◽  
Turlough Downes
Keyword(s):  
Solar Wind ◽  
Cosmic Rays ◽  
Cosmic Ray ◽  
Galactic Cosmic Rays ◽  
The Sun ◽  
Cosmic Ray Intensity ◽  
Chemical Signature ◽  
Exoplanetary Systems ◽  
Life On Earth ◽  
Galactic Cosmic Ray

<p>Cosmic rays may have contributed to the start of life on Earth. Cosmic rays also influence and contribute to atmospheric electrical circuits, cloud cover and biological mutation rates which are important for the characterisation of exoplanetary systems. The flux of Galactic cosmic rays present at the time when life is thought to have begun on the young Earth or in other young exoplanetary systems is largely determined by the properties of the stellar wind. </p> <p>The spectrum of Galactic cosmic rays that we observe at Earth is modulated, or suppressed, by the magnetised solar wind and thus differs from the local interstellar spectrum observed by Voyager 1 and 2 outside of the solar system. Upon reaching 1au, Galactic cosmic rays subsequently interact with the Earth’s magnetosphere and some of their energy is deposited in the upper atmosphere. The properties of the solar wind, such as the magnetic field strength and velocity profile, evolve with time. Generally, young solar-type stars are very magnetically active and are therefore thought to drive stronger stellar winds. </p> <p>Here I will present our recent results which simulate the propagation of Galactic cosmic rays through the heliosphere to the location of Earth as a function of the Sun's life, from 600 Myr to 6 Gyr, in the Sun’s future. I will specifically focus on the flux of Galactic cosmic rays present at the time when life is thought to have started on Earth (~1 Gyr). I will show that the intensity of Galactic cosmic rays which reached the young Earth, by interacting with the solar wind, would have been greatly reduced in comparison to the present day intensity. I will also discuss the effect that the Sun being a slow/fast rotator would have had on the flux of cosmic rays reaching Earth at early times in the solar system's life.</p> <p>Despite the importance of Galactic cosmic rays, their chemical signature in the atmospheres’ of young Earth-like exoplanets may not be observable with instruments in the near future. On the other hand, it may instead be possible to detect their chemical signature by observing young warm Jupiters. Thus, I will also discuss the HR 2562b exoplanetary system as a candidate for observing the chemical signature of Galactic cosmic rays in a young exoplanetary atmosphere with upcoming missions such as JWST.</p>

scholarly journals Internal rotation and dynamics of the Sun from GONG data

1997 ◽  
Vol 181 ◽  
pp. 211-218
Author(s):  
S. G. Korzennik ◽  
M. J. Thompson ◽  
J. Toomre ◽  
Keyword(s):  
World Wide Web ◽  
Internal Rotation ◽  
World Wide ◽  
Power Spectra ◽  
The Sun ◽  
Tata Institute ◽  
The World ◽  
Fundamental Research ◽  
International Collaborative

We report inferences for the Sun's internal rotation from GONG months 4-10 averaged power spectra. In keeping with the international collaborative nature of the GONG project, the results presented here are based on the work of several groups around the world inverting the GONG data and sharing their results via the world-wide web. These groups are at the Observatoire de la Côte d'Azur, Nice (T. Corbard, G. Berthomieu, J. Provost); Theoretical Astrophysics Center, Aarhus (J. Christensen-Dalsgaard, F. Pijpers); Center for Astrophysics, Cambridge MA (A. Eff-Darwich, S. Korzennik); QMW, London (R. Howe, M. Thompson, in collaboration with J. Schou, Stanford); Institute of Astronomy, Cambridge (T. Sekii, D. Gough); University of Sydney (D. Burtonclay, Li Yan, P. Wilson); and Tata Institute of Fundamental Research, Bombay (H. Antia, S. Chitre).

Discovering Ranking Functions for Information Retrieval

2011 ◽  
pp. 377-381
Author(s):  
Weiguo Fan ◽  
Praveen Pathak
Keyword(s):  
Information Retrieval ◽  
World Wide ◽  
Adaptive Algorithms ◽  
Relevant Information ◽  
Ranking Function ◽  
Ranking Functions ◽  
Document Collections ◽  
Retrieval Systems ◽  
The World ◽  
Document Collection

The field of information retrieval deals with finding relevant documents from a large document collection or the World Wide Web in response to a user’s query seeking relevant information. Ranking functions play a very important role in the retrieval performance of such retrieval systems and search engines. A single ranking function does not perform well across different user queries, and document collections. Hence it is necessary to “discover” a ranking function for a particular context. Adaptive algorithms like genetic programming (GP) are well suited for such discovery.

Lightning climatology over the northwest Pacific region: An 11-year study using data from the World Wide Lightning Location Network

2018 ◽  
Vol 210 ◽  
pp. 41-57 ◽  
Author(s):  
Wenjuan Zhang ◽  
Yijun Zhang ◽  
Dong Zheng ◽  
Liangtao Xu ◽  
Weitao Lyu
Keyword(s):  
World Wide ◽  
Northwest Pacific ◽  
Pacific Region ◽  
The World ◽  
Using Data

scholarly journals Anomalous Forbush effects from sources far from Sun center

2008 ◽  
Vol 4 (S257) ◽  
pp. 451-456
Author(s):  
E. Eroshenko ◽  
A. Belov ◽  
H. Mavromichalaki ◽  
V. Oleneva ◽  
A. Papaioannou ◽  
...  
Keyword(s):  
Solar Wind ◽  
Cosmic Ray ◽  
The Sun ◽  
Geomagnetic Disturbances ◽  
Cosmic Ray Intensity ◽  
The Earth ◽  
The Common ◽  
Solar Wind Parameters ◽  
Significant Disturbance ◽  
Forbush Effect

AbstractThe Forbush effects associated with far western and eastern powerful sources on the Sun that occurred on the background of unsettled and moderate interplanetary and geomagnetic disturbances have been studied by data from neutron monitor networks and relevant measurements of the solar wind parameters. These Forbush effects may be referred to a special sub-class of events, with the characteristics like the event in July 2005, and incorporated by the common conditions: absence of a significant disturbance in the Earth vicinity; absence of a strong geomagnetic storm; slow decrease of cosmic ray intensity during the main phase of the Forbush effect. General features and separate properties in behavior of density and anisotropy of 10 GV cosmic rays for this subclass are investigated.

Sign in / Sign up

Export Citation Format

Share Document