Observational features of equatorial coronal hole jets

Collimated ejections of plasma called "coronal hole jets" are commonly observed in polar coronal holes. However, such coronal jets are not only a specific features of polar coronal holes but they can also be found in coronal holes appearing at lower heliographic latitudes. In this paper we present some observations of "equatorial coronal hole jets" made up with data provided by the STEREO/SECCHI instruments during a period comprising March 2007 and December 2007. The jet events are selected by requiring at least some visibility in both COR1 and EUVI instruments. We report 15 jet events, and we discuss their main features. For one event, the uplift velocity has been determined as about 200 km/s, while the deceleration rate appears to be about 0.11 km/s2, less than solar gravity. The average jet visibility time is about 30 minutes, consistent with jet observed in polar regions. On the basis of the present dataset, we provisionally conclude that there are not substantial physical differences between polar and equatorial coronal hole jets.Comment: 9 pages, 8 figures, 1 table, accepted for publication in Annales Geophysicae, Special Issue:'Three eyes on the Sun-multi-spacecraft studies of the corona and impacts on the heliosphere

On the influence of the plasma generated by comet Shoemaker-Levy 9 on Jupiter's magnetic field

The impact of comet Shoemaker-Levy 9 with Jupiter has created a variety of magnetospheric plasmas which were detected by their electromagnetic emissions. By means of the Dessler-Parker-Sckopke relation we estimate the perturbation of Jupiter’s magnetic field. It appears that the produced plasma may explain the observed decrease of UV lines in Io’s torus

Plasma transport in the interplanetary space: Percolation and anomalous diffusion of magnetic-field lines

The magnetic fluctuations due to, e.g., magnetohydrodynamic turbulence cause a magnetic-field line random walk that influences many cosmic plasma phenomena. The results of a three-dimensional numerical simulation of a turbulent magnetic field in plane geometry are presented here. Magnetic percolation, L´evy flights, and non-Gaussian random walk of the magnetic-field lines are found for moderate perturbation levels. In such a case plasma transport can be anomalous, i.e., either superdiffusive or subdiffusive. Increasing the perturbation level a Gaussian diffusion regime is attained. The implications on the structure of the electron foreshock and of planetary magnetopauses are discussed

Defying Unjust Authority: An Exploratory Study

This research explores the psychological factors potentially involved in fostering disobedience to an unjust authority. Our paradigm was modeled after that of the Utrecht Studies on Obedience (Meeus and Raaijmakers European Journal of Social Psychology 16:311-324, 1986) in which participants are ordered to give each of 15 increasingly hostile comments to a participant/victim whenever he fails a trial. Although 30% of our sample followed commands to insult the other participant (confederate), the majority did refuse to do so at some point in the escalating hostility sequence. Our procedure utilized conditions known from prior research to increase the ratio of disobedience to obedience: proximity of teacher to learner plus remote authority. In order to better understand some of the cognitive and affective processes that may predict such defiant behaviour, we utilized a variety of measures, among them, behavioural observations, individual difference assessments, and in depth post-experimental interviews

Methods for characterising microphysical processes in plasmas

Advanced spectral and statistical data analysis techniques have greatly contributed to shaping our understanding of microphysical processes in plasmas. We review some of the main techniques that allow for characterising fluctuation phenomena in geospace and in laboratory plasma observations. Special emphasis is given to the commonalities between different disciplines, which have witnessed the development of similar tools, often with differing terminologies. The review is phrased in terms of few important concepts: self-similarity, deviation from self-similarity (i.e. intermittency and coherent structures), wave-turbulence, and anomalous transport.Comment: Space Science Reviews (2013), in pres

The role of oxygen ions in the formation of a bifurcated current sheet in the magnetotail

Cluster observations in the near-Earth magnetotail have shown that sometimes the current sheet is bifurcated, i.e. it is divided in two layers. The influence of magnetic turbulence on ion motion in this region is investigated by numerical simulation, taking into account the presence of both protons and oxygen ions. The magnetotail current sheet is modeled as a magnetic field reversal with a normal magnetic field component $B_n$, plus a three-dimensional spectrum of magnetic fluctuations $\delta {\bf B}$, which represents the observed magnetic turbulence. The dawn-dusk electric field E$_y$ is also included. A test particle simulation is performed using different values of $\delta {\bf B}$, E$_y$ and injecting two different species of particles, O$^+$ ions and protons. O$^+$ ions can support the formation of a double current layer both in the absence and for large values of magnetic fluctuations ($\delta B/B_0 = 0.0$ and $\delta B/B_0 \geq 0.4$, where B$_0$ is the constant magnetic field in the magnetospheric lobes).Comment: 8 pages, 8 figures. J. Geophys. Res., in pres

A Monte Carlo simulation of magnetic field line tracing in the solar wind

International audienceIt is well known that the structure of magnetic field lines in solar wind can be influenced by the presence of the magnetohydrodynamic turbulence. We have developed a Monte Carlo simulation which traces the magnetic field lines in the heliosphere, including the effects of magnetic turbulence. These effects are modelled by random operators which are proportional to the square root of the magnetic field line diffusion coefficient. The modelling of the random terms is explained, in detail, in the case of numerical integration by discrete steps. Furthermore, a proper evaluation of the diffusion coefficient is obtained by a numerical simulation of transport in anisotropic magnetic turbulence. The scaling of the fluctuation level and of the correlation lengths with the distance from the Sun are also taken into account. As a consequence, plasma transport across the average magnetic field direction is obtained. An application to the propagation of energetic particles from corotating interacting regions to high heliographic latitudes is considered

Out of Mind, Out of Sight: Unexpected Scene Elements Frequently Go Unnoticed Until Primed

Abstract The human visual system employs a sophisticated set of strategies for scanning the environment and directing attention to stimuli that can be expected given the context and a person's past experience. Although these strategies enable us to navigate a very complex physical and social environment, they can also cause highly salient, but unexpected stimuli to go completely unnoticed. To examine the generality of this phenomenon, we conducted eight studies that included 15 different experimental conditions and 1,577 participants in all. These studies revealed that a large majority of participants do not report having seen a woman in the center of an urban scene who was photographed in midair as she was committing suicide. Despite seeing the scene repeatedly, 46 % of all participants failed to report seeing a central figure and only 4.8 % reported seeing a falling person. Frequency of noticing the suicidal woman was highest for participants who read a narrative priming story that increased the extent to which she was schematically congruent with the scene. In contrast to this robust effect of inattentional blindness, a majority of participants reported seeing other peripheral objects in the visual scene that were equally difficult to detect, yet more consistent with the scene. Follow-up qualitative analyses revealed that participants reported seeing many elements that were not actually present, but which could have been expected given the overall context of the scene. Together, these findings demonstrate the robustness of inattentional blindness and highlight the specificity with which different visual primes may increase noticing behavior

Dispositional self-consciousness and hypnotizability

The abeyance of self-consciousness (SC) during hypnosis has beendiscussed as a central aspect of hypnosis, yet dispositional SC hasbeen very rarely evaluated as a correlate of hypnotizability. In thisstudy (N = 328), the authors administered the Harvard Group Scaleof Hypnotic Susceptibility (HGSHS), the Inventory Scale of HypnoticDepth (ISHD), and the Self-Consciousness Scale-Revised (SCS-R).Women tended to score higher than men on the HGSHS, besidesexperiencing greater ISHD automaticity. The Discontinuity (with everydayexperiences) subscale of the ISHD correlated with the Public Self-Consciousness scale of the SCS-R and with the Private Self-Consciousness subscale (using simple, quadratic, and cubic regressions).Being concerned about the perception of others related toexperiencing hypnosis as discontinuous with everyday life, whichalso related to being more introspective and interested in subjectivityat the middle range of scores. The article concludes with suggestionson how to pursue the implications of these results, including testingfor nonlinear relations