CME on March 16, 2001, electron pulsation event and solar-terrestrial phenomena related with CMEs

The electron pulsation event is defined in the paper. Firstly, a slow Halo CME on March 16, 2001 that led to low-energetic solar proton event, electron pulsation event and major geomagnetic storm was analyzed. And then, dozens of events are collected. The interrelations among the solar flare, CME, solar proton event, electron pulsation event and geomagnetic storm are studied. The results show that: (i) Solar proton events can be regarded as the indication that CMEs get to the earth and the electron pulsation events can be regarded as the indication of solar proton flux. (ii) Not only can fast CMEs strongly influence the earth, but also slow CMEs can influence the earth, and its influences are more frequent and cannot be neglected. (iii) Most of high-energetic solar proton events withE≥10 MeV can lead to geomagnetic storms, but most of the medium and weak geomagnetic storms result from low-energetic solar proton events that are caused by CMEs. (iv) Both the electron pulsation events and geomagnetic storms are the link effects of high- and low-energetic solar proton events, but the occurrence of electron pulsation event are generally prior to the geomagnetic storm. So in the circumstance where the near real-time observing data of the low-energetic solar proton event cannot be obtained, we can regard electron pulsation event as the indication of the low-energetic solar proton flux reaching the earth, which can be used as one of the important references of short-term prediction and alert of the geomagnetic storm.     

Radio and EUV signatures of a solar flare-CME event on November 28, 1998

Using the observational data of the solar radio spectrometer with a broad bandwidth of the Chinese National Astronomical Observatories (CNAO), the Nobeyama Radio Heliograph (NoRH) and Polarimeters (NoRP), YOHKOH and SOHO satellites, it is found that there are two characteristics in an X3.3 flare event associated with coronal mass ejection (CME). (ⅰ) X-ray and EUV loop interaction and evolution appeared evidently in corona, followed by the formation of a twisted loop structure, which is consistent with the theoretical calculations of Amari et al. (1999a,b) for the origin of flare-CME events. (ⅱ) The slow frequency drift was shown in the radio observations, corresponding to the relevant movement of the radio source observed by NoRH, at a speed of several tens kilometers per second, which may be associated with the speed of the shock waves resulting from the CME.     

Investigating students' levels of engagement with mathematics: critical events,motivations, and influences on behaviour

Universities invest significant resources in the provision of mathematics tuition to first year students, through both traditional and non-traditional means. Research has shown that a significant minority of students do not engage with these resources appropriately. This paper presents findings from a study of two groups of students at Maynooth University. Both groups had similar mathematical backgrounds on entry to university. The first group consisted of seven students who had failed first year mathematics and had very low levels of engagement with available supports. The second group consisted of nine students who had passed first year mathematics and had engaged with the supports to a significant extent. It emerged that while both groups initially displayed similar tactics and encountered similar difficulties, their levels of reaction to a number of critical events in their mathematical education were key to their engagement levels and their subsequent progression. Further analysis revealed aspects of the students' behaviour which caused them to approach or avoid difficulties. The reasons behind the different student behaviours were investigated, and the main categories of influence on student behaviour which emerged from the interview data were fear, social factors, and motivation.