scholarly journals Predicting the geoeffective properties of coronal mass ejections: current status, open issues and path forward

2019 ◽  
Vol 377 (2148) ◽  
pp. 20180096 ◽  
Author(s):  
A. Vourlidas ◽  
S. Patsourakos ◽  
N. P. Savani
Keyword(s):  
Space Weather ◽  
Coronal Mass Ejections ◽  
Technology Development ◽  
Action Plan ◽  
Current Status ◽  
Weather Impact ◽  
Solar Eruptions ◽  
Holding Back ◽  
Open Issues ◽  
Made In

Much progress has been made in the study of coronal mass ejections (CMEs), the main drivers of terrestrial space weather thanks to the deployment of several missions in the last decade. The flow of energy required to power solar eruptions is beginning to be understood. The initiation of CMEs is routinely observed with cadences of tens of seconds with arc-second resolution. Their inner heliospheric evolution can now be imaged and followed routinely. Yet relatively little progress has been made in predicting the geoeffectiveness of a particular CME. Why is that? What are the issues holding back progress in medium-term forecasting of space weather? To answer these questions, we review, here, the measurements, status and open issues on the main CME geoeffective parameters; namely, their entrained magnetic field strength and configuration, their Earth arrival time and speed, and their mass (momentum). We offer strategies for improving the accuracy of the measurements and their forecasting in the near and mid-term future. To spark further discussion, we incorporate our suggestions into a top-level draft action plan that includes suggestions for sensor deployment, technology development and modelling/theory improvements. This article is part of the theme issue ‘Solar eruptions and their space weather impact’.

scholarly journals Solar Eruptions - the Effects on the Earth’s Environment

2002 ◽  
Vol 12 ◽  
pp. 384-388
Author(s):  
P. Brekke
Keyword(s):  
Space Weather ◽  
Coronal Mass Ejections ◽  
Solar Maximum ◽  
Space Environment ◽  
The Sun ◽  
Technological Systems ◽  
Heliospheric Observatory ◽  
Time Space ◽  
New Information ◽  
Solar Eruptions

AbstractThe response of our space environment to the constantly changing Sun is known as ”Space Weather”. The Solar and Heliospheric Observatory (SOHO) has obtained significant new information about coronal mass ejections (CMEs), the source of the most severe disturbances in the Earth’s environment. Most of the time space weather is of little concern in our everyday lives. However, when the space environment is disturbed by the variable outputs of the Sun, technologies that we depend on both in orbit and on the ground can be affected. The increasing deployment of radiation-, current-, and field-sensitive technological systems over the last few decades and the increasing presence of complex systems in space combine to make society more vulnerable to solar-terrestrial disturbances. Thus, our society is much more sensitive to space weather activity today compared to the last solar maximum. By observing the Sun 24 hours per day, SOHO has proved to be an important “space weather watchdog”. The importance of real-time monitoring of the Sun will be pointed out and a number of enterprises affected by space weather will be discussed.

scholarly journals Introduction to the physics of solar eruptions and their space weather impact

2019 ◽  
Vol 377 (2148) ◽  
pp. 20190152 ◽  
Author(s):  
Vasilis Archontis ◽  
Loukas Vlahos
Keyword(s):  
Space Weather ◽  
Large Scale ◽  
Interplanetary Space ◽  
Active Regions ◽  
Solar Interior ◽  
Physical Processes ◽  
Weather Impact ◽  
Solar Eruptions ◽  
Earth Connection ◽  
Magnetic Disturbances

The physical processes, which drive powerful solar eruptions, play an important role in our understanding of the Sun–Earth connection. In this Special Issue, we firstly discuss how magnetic fields emerge from the solar interior to the solar surface, to build up active regions, which commonly host large-scale coronal disturbances, such as coronal mass ejections (CMEs). Then, we discuss the physical processes associated with the driving and triggering of these eruptions, the propagation of the large-scale magnetic disturbances through interplanetary space and the interaction of CMEs with Earth's magnetic field. The acceleration mechanisms for the solar energetic particles related to explosive phenomena (e.g. flares and/or CMEs) in the solar corona are also discussed. The main aim of this Issue, therefore, is to encapsulate the present state-of-the-art in research related to the genesis of solar eruptions and their space-weather implications. This article is part of the theme issue ‘Solar eruptions and their space weather impact’.

scholarly journals Ionospheric response to solar and interplanetary disturbances: a Swarm perspective

2019 ◽  
Vol 377 (2148) ◽  
pp. 20180098 ◽  
Author(s):  
G. Balasis ◽  
C. Papadimitriou ◽  
A. Z. Boutsi
Keyword(s):  
Solar Cycle ◽  
Electric Fields ◽  
Space Weather ◽  
Low Earth Orbit ◽  
Topside Ionosphere ◽  
Plasma Instabilities ◽  
Radio Communications ◽  
Weather Impact ◽  
Ionospheric Response ◽  
Solar Eruptions

The ionospheric response to solar and interplanetary disturbances has been the subject of intense study for several decades. For 5 years now, the European Space Agency's Swarm fleet of satellites surveys the Earth's topside ionosphere, measuring magnetic and electric fields at low-Earth orbit with unprecedented detail. Herein, we study in situ the ionospheric response in terms of the occurrence of plasma instabilities based on 2 years of Swarm observations. Plasma instabilities are an important element of space weather because they include irregularities like the equatorial spread F events, which are responsible for the disruption of radio communications. Moreover, we focus on three out of the four most intense geospace magnetic storms of solar cycle 24 that occurred in 2015, including the St Patrick's Day event, which is the strongest magnetic storm of the present solar cycle. We examine the associated ionospheric response at Swarm altitudes through the estimation of a Swarm Dst-like index. The newly proposed Swarm derived Dst index may be suitable for space weather applications. This article is part of the theme issue ‘Solar eruptions and their space weather impact’.

scholarly journals Forecasting the space weather impact: The COMESEP project

2012 ◽  
Author(s):  
N. B. Crosby ◽  
A. Veronig ◽  
E. Robbrecht ◽  
B. Vrsnak ◽  
S. Vennerstrom ◽  
...  
Keyword(s):  
Space Weather ◽  
Weather Impact

scholarly journals Current Status of Ceramic Gas Turbine (CGT302)

1998 ◽  
Author(s):  
Hirotake Kobayashi ◽  
Tetsuo Tatsumi ◽  
Takashi Nakashima ◽  
Isashi Takehara ◽  
Yoshihiro Ichikawa
Keyword(s):  
Gas Turbine ◽  
Thermal Efficiency ◽  
Technology Development ◽  
Development Program ◽  
Point Of View ◽  
Current Status ◽  
Fiscal Year ◽  
Inlet Temperature ◽  
Development Organization ◽  
New Energy

In Japan, from the point of view of energy saving and environmental protection, a 300kW Ceramic Gas Turbine (CGT) Research and Development program started in 1988 and is still continuing as a part of “the New Sunshine Project” promoted by the Ministry of International Trade and Industry (MITT). The final target of the program is to achieve 42% thermal efficiency at 1350°C of turbine inlet temperature (TIT) and to keep NOx emissions below present national regulations. Under contract to the New Energy and Industrial Technology Development Organization (NEDO), Kawasaki Heavy Industries, Ltd. (KHI) has been developing the CGT302 with Kyocera Corporation and Sumitomo Precision Products Co., Ltd. By the end of the fiscal year 1996, the CGT302 achieved 37.0% thermal efficiency at 1280°C of TIT. In 1997, TIT reached 1350°C and a durability operation for 20 hours at 1350°C was conducted successfully. Also fairly low NOx was proved at 1300°C of TIT. In January 1998, the CGT302 has achieved 37.4% thermal efficiency at 1250°C TIT. In this paper, we will describe our approaches to the target performance of the CGT302 and current status.

scholarly journals Narrative review of EHDI in South Africa

2015 ◽  
Vol 62 (1) ◽  
Author(s):  
Selvarani Moodley ◽  
Claudine Storbeck
Keyword(s):  
South Africa ◽  
Hearing Loss ◽  
Hearing Screening ◽  
Narrative Review ◽  
Current Status ◽  
Western Cape ◽  
Comprehensive Overview ◽  
National Priority ◽  
Newborn Hearing ◽  
Made In

Background: With 17 babies born with hearing loss every day in South Africa, there is a pressing need for systematic Early Hearing Detection and Intervention (EHDI) services. Progress is being made in offering newborn hearing screening and studies have been conducted to document these processes within South Africa. However, due to the lack of a national and holistic overview of EHDI services to date, an accurate picture of the current status of EHDI within the South African context is required. Objective: To document and profile what has been published within the field of EHDI in South Africa over the last two decades (Jan 1995–Sept 2014) in order to gain a comprehensive overview of the current status and practice of screening and diagnosis in the field of paediatric hearing loss. Method: A narrative review of peer-reviewed articles related to EHDI in South Africa was conducted by searching the EBSCOHOST, SCOPUS and JSTOR databases for the period January 1995 to September 2014. Results: Results indicate that over the last two decades research and publications in the field of EHDI have increased considerably. These publications have revealed extensive knowledge related to paediatric hearing screening and intervention services in South Africa; however, this knowledge seems to be limited primarily to the provinces of Gauteng and the Western Cape. Furthermore, studies pertaining to diagnosis have revealed that, although much has been written on the scientific aspects on tools for diagnosis of hearing loss, there is a lack of comprehensive information on diagnostic protocols and procedures. Conclusion: Despite the clear progress being made in South Africa in the field of early hearing detection and intervention, there is a need for comprehensive studies on protocols and procedures in diagnosing paediatric hearing loss. Finally, the narrative review revealed a clear need to ensure that development and growth in the field of EHDI is a national priority and extends beyond the two provinces currently showing growth.

scholarly journals A look at university dropout in Moroccan higher education

2017 ◽  
Vol 7 (9) ◽  
Author(s):  
Zoulal MANSOURI ◽  
Mohamed El Amine MOUMINE
Keyword(s):  
Higher Education ◽  
Action Plan ◽  
Dropping Out ◽  
Education Reforms ◽  
Review Of The Literature ◽  
Higher Education Reforms ◽  
Strategic Vision ◽  
University Dropout ◽  
And Training ◽  
Made In

This article takes stock of the aspects of higher education provision invested in the fight against the phenomenon of dropping out of university. These aspects are exposed from a review of the literature on higher education reforms in Morocco since 1999. Chronologically, they are reviewed in the National Charter for Education and Training 1999, in the Plan of Emergency 2009-2012, in the Action Plan 2013-2016, and finally, in the Strategic Vision of the Reform 2015-2030. It is concluded that despite the efforts made in quantitative retention étudiantsà university until graduation, progress still to make qualitatively.

scholarly journals The Tor Vergata Synoptic Solar Telescope (TSST): A robotic, compact facility for solar full disk imaging

2020 ◽  
Vol 10 ◽  
pp. 58
Author(s):  
Luca Giovannelli ◽  
Francesco Berrilli ◽  
Daniele Calchetti ◽  
Dario Del Moro ◽  
Giorgio Viavattene ◽  
...  
Keyword(s):  
Solar Atmosphere ◽  
Space Weather ◽  
Coronal Mass Ejections ◽  
Low Cost ◽  
Optical Filter ◽  
Solar Telescope ◽  
The Sun ◽  
Weather Events ◽  
Line Observation ◽  
Full Disk

By the continuous multi-line observation of the solar atmosphere, it is possible to infer the magnetic and dynamical status of the Sun. This activity is essential to identify the possible precursors of space weather events, such as flare or coronal mass ejections. We describe the design and assembly of TSST (Tor Vergata Synoptic Solar Telescope), a robotic synoptic telescope currently composed of two main full-disk instruments, a Hα telescope and a Potassium (KI D1) magneto-optical filter (MOF)-based telescope operating at 769.9 nm. TSST is designed to be later upgraded with a second MOF channel. This paper describes the TSST concepts and presents the first light observation carried out in February 2020. We show that TSST is a low-cost robotic facility able to achieve the necessary data for the study of precursors of space weather events (using the magnetic and velocity maps by the MOF telescope) and fast flare detection (by the Hα telescope) to support Space Weather investigation and services.

3D MHD study of the Earth magnetosphere response during extreme space weather conditions

2021 ◽  
Author(s):  
Jacobo Varela Rodriguez ◽  
Sacha A. Brun ◽  
Antoine Strugarek ◽  
Victor Réville ◽  
Filippo Pantellini ◽  
...  
Keyword(s):  
Solar Wind ◽  
Space Weather ◽  
Coronal Mass Ejections ◽  
Main Sequence ◽  
Dynamic Pressure ◽  
Weather Conditions ◽  
The Sun ◽  
Earth Surface ◽  
The Earth ◽  
The Imf

<p><span>The aim of the study is to analyze the response of the Earth magnetosphere for various space weather conditions and model the effect of interplanetary coronal mass ejections. The magnetopause stand off distance, open-closed field lines boundary and plasma flows towards the planet surface are investigated. We use the MHD code PLUTO in spherical coordinates to perform a parametric study regarding the dynamic pressure and temperature of the solar wind as well as the interplanetary magnetic field intensity and orientation. The range of the parameters analyzed extends from regular to extreme space weather conditions consistent with coronal mass ejections at the Earth orbit. The direct precipitation of the solar wind on the Earth day side at equatorial latitudes is extremely unlikely even during super coronal mass ejections. For example, the SW precipitation towards the Earth surface for a IMF purely oriented in the Southward direction requires a IMF intensity around 1000 nT and the SW dynamic pressure above 350 nPa, space weather conditions well above super-ICMEs. The analysis is extended to previous stages of the solar evolution considering the rotation tracks from Carolan (2019). The simulations performed indicate an efficient shielding of the Earth surface 1100 Myr after the Sun enters in the main sequence. On the other hand, for early evolution phases along the Sun main sequence once the Sun rotation rate was at least 5 times faster (< 440 Myr), the Earth surface was directly exposed to the solar wind during coronal mass ejections (assuming today´s Earth magnetic field). Regarding the satellites orbiting the Earth, Southward and Ecliptic IMF orientations are particularly adverse for Geosynchronous satellites, partially exposed to the SW if the SW dynamic pressure is 8-14 nPa and the IMF intensity 10 nT. On the other hand, Medium orbit satellites at 20000 km are directly exposed to the SW during Common ICME if the IMF orientation is Southward and during Strong ICME if the IMF orientation is Earth-Sun or Ecliptic. The same way, Medium orbit satellites at 10000 km are directly exposed to the SW if a Super ICME with Southward IMF orientation impacts the Earth.</span></p><p>This work was supported by the project 2019-T1/AMB-13648 founded by the Comunidad de Madrid, grants ERC WholeSun, Exoplanets A and PNP. We extend our thanks to CNES for Solar Orbiter, PLATO and Meteo Space science support and to INSU/PNST for their financial support.</p>

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