What do we learn from ground level enhancements?

Ground level enhancements (GLEs) comprise the high-energy end of solar energetic particle (SEP) events and constitute a special class in which ions are accelerated to relativistic energies, causing a significant sudden increase of cosmic rays at ground-based detectors, mainly at neutron monitors (NMs). GLEs require acceleration processes capable of producing particles with sufficient energy to allow their secondary products to reach the terrestrial ground and be detected. Moreover, due to their fast propagation, relativistic protons in GLEs are particularly useful for the identification of SEP sources at the Sun (i.e. flare, coronal mass ejections) – nonetheless, the debate about the exact nature of GLE mechanisms is still ongoing. GLEs are further critical for the establishment of Space Weather services and the accurate determination of their imposed radiation risk. In this tutorial, an overview of GLEs with respect to their historical identification, measurements from the worldwide neutron monitor network, modeling and forecasting efforts will be provided. In addition, a hands-on tutorial that will demonstrate how the Neutron Monitor Database (NMDB) can be utilized for GLE analysis will be conducte

Advancing task involvement, intrinsic motivation and metacognitive regulation in physical education classes: the self-check style of teaching makes a difference

It was hypothesized that “self-check” style of teaching would be more preferable in terms of creating a mastery-oriented climate, and promoting adaptive achievement goals, intrinsic motivation and metacognitive activity in physical education classes. Two hundred seventy-nine (N = 269) 6-grade students were randomly divided into two groups that were taught four consecutive physical education lessons of the same content following either “practice” or “self-check” styles of teaching respectively. Students responded on questionnaires prior and after the intervention. Results revealed significant interactions between groups and measurements. Students in the “self-check” style group scored higher in scales measuring mastery-oriented climate, mastery goal, intrinsic motivation and metacognitive processes and lower in scales measuring performance-goals and performance-oriented motivational climate. These results underscore the importance of using styles of teaching that enhance opportunities for deep cognitive processing and promote mastery-goals and mastery-oriented climates

Applied Research Automatic Self-Talk Questionnaire for Sports (ASTQS): Development and Preliminary Validation of a Measure Identifying the Structure of Athletes’ Self-Talk

The aim of the present investigation was to develop an instrument assessing the con­tent and the structure of athletes’ self-talk. The study was conducted in three stages. In the first stage, a large pool of items was generated and content analysis was used to organize the items into categories. Furthermore, item-content relevance analysis was conducted to help identifying the most appropriate items. In Stage 2, the factor struc­ture of the instrument was examined by a series of exploratory factor analyses (Sample A: N = 507), whereas in Stage 3 the results of the exploratory factor analysis were retested through confirmatory factor analyses (Sample B: N = 766) and at the same time concurrent validity were assessed. The analyses revealed eight factors, four pos­itive (psych up, confidence, anxiety control and instruction), three negative (worry, disengagement and somatic fatigue) and one neutral (irrelevant thoughts). The find­ings of the study provide evidence regarding the multidimensionality of self-talk, suggesting that ASTQS seems a psychometrically sound instrument that could help us developing cognitive-behavioral theories and interventions to examine and modify athletes’ self-talk

Pricing and Simulating Catastrophe Risk Bonds in a Markov-dependent Environment

At present, insurance companies are seeking more adequate liquidity funds to cover the insured property losses related to natural and manmade disasters. Past experience shows that the losses caused by catastrophic events, such as earthquakes, tsunamis, floods, or hurricanes, are extremely high. An alternative method for covering these extreme losses is to transfer part of the risk to the financial markets by issuing catastrophe-linked bonds. In this paper, we propose a contingent claim model for pricing catastrophe risk bonds (CAT bonds). First, using a two-dimensional semi-Markov process, we derive analytical bond pricing formulae in a stochastic interest rate environment with aggregate claims that follow compound forms, where the claim inter-arrival times are dependent on the claim sizes. Furthermore, we obtain explicit CAT bond prices formulae in terms of four different payoff functions. Next, we estimate and calibrate the parameters of the pricing models using catastrophe loss data provided by Property Claim Services from 1985 to 2013. Finally, we use Monte Carlo simulations to analyse the numerical results obtained with the CAT bond pricing formulae

SEP spectra derived from neutron monitor data and from EPHIN space detector data during recent GLEs and sub-GLEs

The Electron Proton Helium Instrument (EPHIN) aboard the Solar Heliospheric Observatory (SOHO) observed several SEP events with protons accelerated to energies E>500 MeV, whereas no neutron monitor (NM) of the worldwide network showed a significant increase in their counting rate. For instance, the SEP event on 8 November 2000 with maximum proton intensity at 500 MeV of >0.1 (cm2 s sr MeV)-1 is outstanding, as this maximum pro-ton flux is comparable with the GLEs on 14 July 2000 and on 15 April 2001 (max. count rate increase in 5-min data of 225% at South Pole NM). In a first step we applied a forward modelling approach of the SEP event on 8 November 2000, i.e. we computed the expected NM count rate increases for selected NM stations, utilizing as input para-meters the SEP spectra determined from EPHIN data as well as anticipated pitch angle distribution and apparent source direction. The simulated count rate increases for selected NM stations showed that this SEP event should have be seen as a clear GLE. To further understand this situation, we investigated in a next step recent GLEs and sub-GLEs. Consequently, a total of four SEP events were selected, two clearly identified GLEs and two sub-GLEs. We performed a “GLE analysis” based on the data of the worldwide network of NMs for each of the four SEP events and then compared the derived SEP spectra with the proton spectra as determined from EPHIN measurements

Solar Energetic Particles in the Inner Heliosphere: Status and Open Questions

Solar energetic particle (SEP) events are related to both solar flares and coronal mass ejections (CMEs) and they present energy spectra that span from a few keV up to several GeV. A wealth of observations from widely distributed spacecraft have revealed that SEPs fill very broad regions of the heliosphere, often all around the Sun. High energy SEPs can sometimes be energetic enough to penetrate all the way down to the surface of the Earth and thus be recorded on the ground as ground level enhancements (GLEs). The conditions of the radiation environment are currently unpredictable due to an as-yet incomplete understanding of solar eruptions and their corresponding relation to SEP events. This is because the complex nature and the interplay of the injection, acceleration and transport processes undergone by the SEPs in the solar corona and the interplanetary space prevent us from establishing an accurate understanding (based on observations and modelling). In this work, we review the current status of knowledge on SEPs, focusing on GLEs and multi-spacecraft events. We extensively discuss the forecasting and nowcasting efforts of SEPs, dividing these into three categories. Finally, we report on the current open questions and the possible direction of future research efforts. This article is part of the theme issue Solar eruptions and their space weather impact