CLUSTER and IMAGE: New Ways to Study the Earth’s Plasmasphere

摘要: Ground-based instruments and a number of space missions have contributed to our knowledge the plasmasphere since its discovery half century ago, but it is fair say that many questions remained unanswered. Recently, NASA’s Image ESA’s Cluster probes introduced new observational concepts, thereby providing non-local view plasmasphere. carried an extreme ultraviolet imager producing global pictures Its instrumentation also included radio sounder for remotely sensing spacecraft environment. The mission provides observations at four nearby points as four-spacecraft configuration crosses outer on every perigee pass, giving idea field plasma gradients electric current density. This paper starts with historical overview classical single-spacecraft data interpretation, discusses nature measurements, emphasizes importance interpretation tools been developed extract information from these observations. reviews innovative techniques highlights some them give flavor methods. In doing so, shown how perspective opens avenues plasmaspheric research.