Asunto(s)
Craneotomía , Procesamiento de Imagen Asistido por Computador/instrumentación , Neoplasias Meníngeas/diagnóstico por imagen , Meningioma/diagnóstico por imagen , Tomografía Computarizada por Rayos X/instrumentación , Simulación por Computador , Femenino , Humanos , Neoplasias Meníngeas/cirugía , Meningioma/cirugía , Persona de Mediana Edad , Hueso Petroso/diagnóstico por imagen , Hueso Petroso/cirugía , Neoplasias Craneales/diagnóstico por imagen , Neoplasias Craneales/cirugía , Programas Informáticos , Hueso Esfenoides/diagnóstico por imagen , Hueso Esfenoides/cirugíaRESUMEN
Large-scale, electric currents flowing along magnetic field lines into the polar regions of Earth are thought to be the main contributors of the energy that powers the ionospheric aurora. However, we have found evidence for global contributions from electromagnetic waves (Alfvén waves). Data that were collected from the Polar spacecraft over the course of 1 year show that the flow of wave electromagnetic energy at altitudes of 25,000 to 38,000 kilometers delineates the statistical auroral oval. The Poynting flux of individual events distributed along the auroral oval was larger than 5 ergs per square centimeter per second, which is sufficient to power auroral acceleration processes. This evidence suggests that in addition to magnetic field-aligned currents, the dayside and nightside aurora is globally powered by the energy flow of these high-altitude Alfvén waves.