A statistical study of the global structure of the ring current

[1] In this paper we derive the average configuration of the ring current as a function of the state of the magnetosphere as indicated by the Dst index. We sort magnetic field data from the Combined Release and Radiation Effects Satellite (CRRES) by spatial location and by the Dst index in order to produce magnetic field maps. From these maps we calculate local current systems by taking the curl of the magnetic field. We find both the westward (outer) and the eastward (inner) components of the ring current. We find that the ring current intensity varies linearly with Dst as expected and that the ring current is asymmetric for all Dst values. The azimuthal peak of the ring current is located in the afternoon sector for quiet conditions and near midnight for disturbed conditions. The ring current also moves closer to the Earth during disturbed conditions. We attempt to recreate the Dst index by integrating the magnetic perturbations caused by the ring current. We find that we need to multiply our computed disturbance by a factor of 1.88 ± 0.27 and add an offset of 3.84 ± 4.33 nT in order to get optimal agreement with Dst. When taking into account a tail current contribution of roughly 25%, this agrees well with our expectation of a factor of 1.3 to 1.5 based on a partially conducting Earth. The offset that we have to add does not agree well with an expected offset of approximately 20 nT based on solar wind pressure

Loi de position ou durée vocalique?

Cet article défend la « loi de position », selon laquelle les voyelles françaises en syllabe fermée tendent à s’ouvrir, et les voyelles en syllabe ouverte, à se fermer, contre les arguments de Y.-C. Morin, pour qui la qualité des voyelles françaises se rapporte surtout à leur longueur en français moyen. Il est admis que si elle rend mieux compte du vocalisme de certains parlers français que la thèse de Morin, la soi-disante « loi » admet beaucoup d’exceptions en français académique. On peut pourtant dire la même chose de l’hypothèse Morin, et la « loi » se situe d’ailleurs sur un plan différent, puisqu’elle se rapporte au devenir de la langue, plutôt qu’à son état contemporain.The "loi de position", according to which French vowels tend to open in closed syllables, and close in open ones, is defended against Y.-C. Morin's view that the quality of French vowels is above all related to their length in Middle French. It is admitted that although the "law" accounts more satisfactorily for the vowel-system of some French parlers, there are still many exceptions to it in contemporary standard French. However, the same is true of Morin's hypothesis, and in any case, the "law" operates on a different plane, since it relates to a continuing movement within the language, rather than to its present state

Quantifying the AGN-driven ionised outflows in local Ultra-luminous Infrared Galaxies

Active-Galactic-Nuclei(AGN)-driven outflows are now routinely incorporated into models of major gas-rich mergers, as a mechanism for regulating galaxy growth. This is required to reproduce the correct observables (e.g. M-sigma relation) in such simulations. Despite this, the true importance of the AGN-driven outflows remains controversial from an observational perspective. In particular, the properties of these outflows - such as the radii, densities, mass outflow rates and coupling efficiencies - have proven challenging to quantify, and previous estimates vary over many orders of magnitude. Here, high-resolution imaging and wide-spectral-coverage spectroscopy has been used to accurately quantify the warm outflows in a sample of 9 local (z 5 kpc) low-surface-brightness emission-line regions seen in 60% of a more extended sample of local ULIRGs have been shown to contribute little to the total outflow powers. Overall, this thesis contributes some of the most accurately derived properties for the warm outflows in local AGN, and provides observational results which can be used for testing the merger models

Modeling radiation belt radial diffusion in ULF wave fields: 1. Quantifying ULF wave power at geosynchronous orbit in observations and in global MHD model

[1] To provide critical ULF wave field information for radial diffusion studies in the radiation belts, we quantify ULF wave power (f = 0.5–8.3 mHz) in GOES observations and magnetic field predictions from a global magnetospheric model. A statistical study of 9 years of GOES data reveals the wave local time distribution and power at geosynchronous orbit in field-aligned coordinates as functions of wave frequency, solar wind conditions (Vx, ΔPd and IMF Bz) and geomagnetic activity levels (Kp, Dst and AE). ULF wave power grows monotonically with increasing solar wind Vx, dynamic pressure variations ΔPd and geomagnetic indices in a highly correlated way. During intervals of northward and southward IMF Bz, wave activity concentrates on the dayside and nightside sectors, respectively, due to different wave generation mechanisms in primarily open and closed magnetospheric configurations. Since global magnetospheric models have recently been used to trace particles in radiation belt studies, it is important to quantify the wave predictions of these models at frequencies relevant to electron dynamics (mHz range). Using 27 days of real interplanetary conditions as model inputs, we examine the ULF wave predictions modeled by the Lyon-Fedder-Mobarry magnetohydrodynamic code. The LFM code does well at reproducing, in a statistical sense, the ULF waves observed by GOES. This suggests that the LFM code is capable of modeling variability in the magnetosphere on ULF time scales during typical conditions. The code provides a long-missing wave field model needed to quantify the interaction of radiation belt electrons with realistic, global ULF waves throughout the inner magnetosphere

Making it in academic psychology: Demographic and personality correlates of eminence

Citations to published work, personality, and demographic characteristics were examined in a sample of male and female academic psychologists. A large sex difference was found in citations with men receiving significantly more recognition. Reputational rankings of graduate school and current institution were significantly related to citations, as were components of achievement motivation. Mastery and work needs were positively related to citations while competitiveness was negatively associated with the criterion. A model of attainment in psychology is proposed and possible explanations for the differential recognition of women are explored

Ion observations from geosynchronous orbit as a proxy for ion cyclotron wave growth during storm times

[1] There is still much to be understood about the processes contributing to relativistic electron enhancements and losses in the radiation belts. Wave particle interactions with both whistler and electromagnetic ion cyclotron (EMIC) waves may precipitate or accelerate these electrons. This study examines the relation between EMIC waves and resulting relativistic electron flux levels after geomagnetic storms. A proxy for enhanced EMIC waves is developed using Los Alamos National Laboratory Magnetospheric Plasma Analyzer plasma data from geosynchronous orbit in conjunction with linear theory. In a statistical study using superposed epoch analysis, it is found that for storms resulting in net relativistic electron losses, there is a greater occurrence of enhanced EMIC waves. This is consistent with the hypothesis that EMIC waves are a primary mechanism for the scattering of relativistic electrons and thus cause losses of such particles from the magnetosphere