Global magnetospheric imaging

Abstract

Understanding the formation and behavior of the Earth's vast high‐altitude environment, its magnetosphere, requires both local in situ measurements and global observations. The in situ observations performed over the past decades have provided both a completely new perspective of this environment and an understanding of many localized processes operating in it. The observations have been further synthesized to provide a valuable first impression of the global nature of the magnetosphere. This initial global construction has been very beneficial in summarizing past results and guiding future work in the field, yet many fundamental questions remain unresolved. This is because, until recently, the global magnetosphere has not been observed, even in part; it has remained invisible, and its actual shape and large‐scale dynamics remain mysteries. Now new developments and results have demonstrated the feasibility of obtaining such global images. These techniques include the detection of photons at X ray, extreme ultraviolet, ultraviolet, and visible wavelengths, radio emissions, and energetic neutral atoms. Taken together, such emissions can be used to form images of most of the magnetosphere proper: the aurora, plasmasphere, boundary regions, ring current, and plasma sheet. This paper describes the demonstrated and developing techniques for global magnetospheric imaging and discusses the scientific expectations of having global observations in conjunction with local measurements.