Lithium masquerading as the solar wind.AT0047 In reanalyzing measurements of lithium ions released in 1984 from an Earth-orbiting satellite, scientists have found that the ions apparently distorted or perturbed per·turb tr.v. per·turbed, per·turb·ing, per·turbs 1. To disturb greatly; make uneasy or anxious. 2. To throw into great confusion. 3. the structure of the planet's magnetic field in a way that was earlier attributed to density changes in the solar wind. Researchers originally had hoped to use the ions as "tracers" of Earth's magnetic field Earth's magnetic field (and the surface magnetic field) is approximately a magnetic dipole, with one pole near the north pole (see Magnetic North Pole) and the other near the geographic south pole (see Magnetic South Pole). lines after the charged particles were ejected from a satellite called the Active Magnetosphere Particle Tracer Experiment. They failed, however, to detect the ions. Earth's magnetic field lines often change with fluctuations in the pressure of the solar wind, and they changed during the lithium release. However, the solar wind's density was very stable" at the time of the ion release, according to a report in the December 1990 GEOPHYSICAL RESEARCH LETTERS Geophysical Research Letters is a publication of the American Geophysical Union. GRL is the organization's only letters journal. Since its introduction in 1974, GRL has published only short research letters, typically 3-5 pages long, which focus on a specific discipline or by Thomas A. Potemra of the Johns Hopkins University Johns Hopkins University, mainly at Baltimore, Md. Johns Hopkins in 1867 had a group of his associates incorporated as the trustees of a university and a hospital, endowing each with $3.5 million. Daniel C. Applied Physics Laboratory The Johns Hopkins University Applied Physics Laboratory (APL), located in Laurel, Maryland, is a not-for-profit, university-affiliated research center employing 4,000 people. in Laurel, Md., Hermann Luhr of the Institute for Geophysics and Meteorology in Braunschweig, Germany, and Wolfgang Baumjohann of the Max Planck Institute in Munich, Germany The researchers thus conclude that the increased density of the lithium ion "cloud" distorted the field lines. Potemra says the distorted field was "the first positive indication" inside Earth's magnetosphere of the experimental ion release, which occurred outside the magnetosphere. |
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