On the transmission of compressional fluctuations from the solar wind to the magnetosphere: an analysis of critical aspects  

2021 ◽  
Author(s):  
Umberto Villante ◽  
Simone Di Matteo ◽  
Dario Recchiuti
Keyword(s):  
Solar Wind ◽  
Spectral Analysis ◽  
Analytical Methods ◽  
Wave Activity ◽  
Geostationary Orbit ◽  
Interplanetary Shocks ◽  
Shock Impact ◽  
The Relationship ◽  
Critical Aspects

<div> <p>An important aspect of the interaction between the solar wind (SW) and the magnetosphere concerns the relationship between the SW structures/fluctuations and the onset/transmission of the magnetospheric wave modes. Several critical aspects may influence the results of similar analysis: for example, the frequency of fluctuations that are expected to impinge the magnetosphere may be not the same when they are observed by spacecraft at different places in front of the magnetosphere and the choice of the analytical methods adopted for the spectral analysis might influence the frequency estimate (as well as the wave identification) both in the SW and in the magnetosphere (Di Matteo and Villante, 2017, 2018). Focusing attention on these aspects, we present an analysis of SW compressional fluctuations (f ≈ 1-5 mHz), following two interplanetary shocks, as observed by two spacecraft at different places and compared them with the magnetospheric fluctuations following the corresponding sudden impulses, observed by two satellites at geostationary orbit and at several ground-based stations. Our results confirm that the comparison of different methods of spectral analysis is crucial to obtain a definite estimate of the characteristics of fluctuations in each region. For a case study, in which SW fluctuations at the same frequencies were observed by both interplanetary spacecraft, we found that all fluctuations observed in the magnetosphere were related to SW compressional fluctuations approximately at the same frequencies, with no evidence for wave activity of internal origin, or directly driven by the shock impact.</p> <p> </p> </div>

Triggered Substorms

1996 ◽  
Author(s):  
Charles F. Kennel
Keyword(s):  
Solar Wind ◽  
Growth Phase ◽  
Recovery Phase ◽  
Geostationary Orbit ◽  
Small Scale ◽  
Threshold Condition ◽  
Interplanetary Shocks ◽  
Reconnection Rate ◽  
Present Evidence ◽  
Auroral Substorm

Do events in the solar wind “trigger” substorms, or do substorms occur independently? Is there a difference between triggered and untriggered substorms? What kinds of events trigger onsets? Expansions? Can we learn about their physics from the things that do and do not trigger them? Does the switch from expansion to recovery phase require external prompting? Even if it is not required, can the recovery be prompted anyway? If conditions in the solar wind are steady, can we still have substorms? In this chapter, we review studies that have addressed questions like these. “Pseudoexpansions” resemble the first several minutes of development of the dipolarization and westward surge, but later fail to sustain an expanding current wedge or auroral bulge (Section 15.2). They may be triggered by minor dayside reconnection events that occur before the threshold condition for the full substorm is reached. Interplanetary shocks can trigger a substorm within minutes of their arrival at earth, provided they are sufficiently strong and a growth phase is already in progress (Section 15.3). Other compressional solar wind discontinuities also can trigger substorms, but rarefactions cannot. Northward turnings of the interplanetary field can also trigger substorms after a growth phase has already started (Section 15.4). During intervals of steady southward interplanetary field, either quasisteady convection bays or quasiperiodically recurring substorms can occur (Section 15.5). An inkling of pseudoexpansion behavior has been around since before the auroral substorm existed (Elvey, 1957), and in his original paper Akasofu (1964) not only had taken them into account but suggested that they occur on other than the most equatorward arc. Later, Davis and Hallinan (1976) and Untiedt et al. (1978) pointed out that pseudoexpansions are brief activations of local small-scale auroral spirals to the ground observer. Now it appears that pseudoexpansions are attenuated versions of complete expansions in several important respects: brightening of an auroral arc, Pi 2 pulsation bursts, and enhancements of the auroral electrojet, (McPherron, 1991). In this section, we show the auroral pseudoexpansion has a counterpart in geostationary orbit, and present evidence that both may be responses to variations in the dayside reconnection rate.

scholarly journals Barriers and Challenges for the Implementation of the Integrated Tariff in Ukraine on the Case of Kyiv City

2019 ◽  
Vol 12 (4) ◽  
pp. 428-443
Author(s):  
Vladyslav Kolomechiuk
Keyword(s):  
Future Development ◽  
Government Policy ◽  
Transport Services ◽  
Smart Mobility ◽  
Barriers And Challenges ◽  
The Relationship ◽  
The City ◽  
The Eu ◽  
Critical Aspects

SummarySubject and purpose of work: Integrated fare to date is essential for the efficient functioning of city transport services and for the involvement of citizens to shift from private to public transport. Implementation of this kind is a necessary component of the future development of the city in the direction of smart mobility.Materials and methods: The research focuses on evaluating the barriers and challenges towards the implementation of an integrated fare in Ukraine, mainly using the city of Kyiv as a case study.Results: The article analyzes early attempts to introduce an integrated fare, problems in the way of implementation and, basically, the experience of the EU cities, which may later be adopted. Next, it outlines some critical aspects in the relationship between government policy, city authorities, transport operators and city residents in the context of the introduction of an integrated fare.Conclusions: The study highlights such priority challenges as legal, organizational, technical and social.

Kämpfe um Bergbau und die Möglichkeiten demokratischer Transformation

2017 ◽  
Vol 47 (189) ◽  
Author(s):  
Kristina Dietz
Keyword(s):  
Direct Democracy ◽  
Social Power ◽  
Political Agenda ◽  
The Political ◽  
Liberal Democratic ◽  
Political Effects ◽  
Mining Project ◽  
National Governments ◽  
The Relationship

The article explores the political effects of popular consultations as a means of direct democracy in struggles over mining. Building on concepts from participatory and materialist democracy theory, it shows the transformative potentials of processes of direct democracy towards democratization and emancipation under, and beyond, capitalist and liberal democratic conditions. Empirically the analysis is based on a case study on the protests against the La Colosa gold mining project in Colombia. The analysis reveals that although processes of direct democracy in conflicts over mining cannot transform existing class inequalities and social power relations fundamentally, they can nevertheless alter elements thereof. These are for example the relationship between local and national governments, changes of the political agenda of mining and the opening of new spaces for political participation, where previously there were none. It is here where it’s emancipatory potential can be found.

Interactive acculturation of Turkish-Belgian parents and children in Flanders: A case study of Beringen

2019 ◽  
Vol 16 (3) ◽  
pp. 417-428
Author(s):  
Özgün Ünver ◽  
Ides Nicaise
Keyword(s):  
Early Childhood ◽  
Maternal Employment ◽  
Domain Specificity ◽  
Specific Context ◽  
Childhood Education ◽  
Parents And Children ◽  
Education And Care ◽  
The Relationship ◽  
The Town

This article tackles the relationship between Turkish-Belgian families with the Flemish society, within the specific context of their experiences with early childhood education and care (ECEC) system in Flanders. Our findings are based on a focus group with mothers in the town of Beringen. The intercultural dimension of the relationships between these families and ECEC services is discussed using the Interactive Acculturation Model (IAM). The acculturation patterns are discussed under three main headlines: language acquisition, social interaction and maternal employment. Within the context of IAM, our findings point to some degree of separationism of Turkish-Belgian families, while they perceive the Flemish majority to have an assimilationist attitude. This combination suggests a conflictual type of interaction. However, both parties also display some traits of integrationism, which points to the domain-specificity of interactive acculturation.

The Relationship between Working Environment and Internship Satisfaction Level: A Case Study Of A 4-Star Hotel Restaurant In Germany

2019 ◽  
Vol 2 (4) ◽  
pp. 276-291
Author(s):  
Chatarina Natalia Putri
Keyword(s):  
Career Development ◽  
Working Hours ◽  
Learning Opportunities ◽  
Working Environment ◽  
The Other ◽  
Satisfaction Level ◽  
Supervisory Support ◽  
Support Organization ◽  
The Relationship

There are many factors that can lead to internship satisfaction. Working environment is one of the factors that will result to such outcome. However, many organizations discarded the fact of its importance. The purpose of this study is to determine whether there is a significant relationship between working environment and internship satisfaction level as well as to determine whether the dimensions of working environment significantly affect internship satisfaction. The said dimensions are, learning opportunities, supervisory support, career development opportunities, co-workers support, organization satisfaction, working hours and esteem needs. A total of 111 questionnaires were distributed to the respondents and were processed by SPSS program to obtain the result of this study. The results reveal that learning opportunities, career development opportunities, organization satisfaction and esteem needs are factors that contribute to internship satisfaction level. In the other hand, supervisory support, co-workers support and working hours are factors that lead to internship dissatisfaction. The result also shows that organization satisfaction is the strongest factor that affects internship satisfaction while co-workers support is the weakest.

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