Next Generation Auroral Imaging From Space

Geospace multi-scale dynamics are projected (albeit imperfectly) onto the upper atmosphere via the aurora, and consequently auroral observations provide us with our best way of observing geospace at the system-level. Over the last 40 years, there have been great successes in auroral imaging from space. Still, we must acknowledge that there are shortcomings. For example, true daylight suppression has eluded us, and the dynamic range of past auroral imagers has not been sufficient to allow for reliable determination of the open-closed boundary (OCB) from auroral images. As well, the spatial resolution of satellite-borne imagers to date has not been sufficient to enable tracking of dynamic auroral features such as arcs. Finally, all auroral imaging missions to date have been single satellite, so that we have never imaged complete sequences spanning long-duration processes such as storms and SMC events. Much more importantly, the inability to specify the OCB means we have never reliably measured the time series of open flux, and so the fundamental driver of all geospace dynamics has never been quantified. In terms of the underlying dynamics of geospace, we have yet to specify the space/time distribution of auroral structures across all relevant scales, so transients and the non-equilibrium cascade cannot be studied within the context of the overall system dynamics. In this talk, we present the results of a decade of planning for the "next generation" of auroral imaging. We discuss how new imaging technologies, flown on three-axis stabilized satellites will allow for accurate specification of the OCB at all local times, for near-perfect suppression of daylight and thus excellent dayside auroral imaging, and spatial resolution allowing for identification and tracking of arcs, patches, and other features that have never been imaged globally. We present the significant advantages of a two-satellite imaging mission as envisaged for the concepts of Canada's Ravens and PCW missions, and China's Kuafu B satellite pair. Finally, we argue that 24/7 "next generation" auroral imaging, complimented by equally innovative ENA and X-ray imaging, will form the cornerstone of what we call the Great Geospace Observatory.