Assimilation of GIRO data into a real‐time IRI

Abstract

Increasingly accurate and detailed global 3‐D specification of the Earth's space plasma environment is required to further understand its intricate organization and behavior. For a long time space physics and aeronomy research has been data starved due to the great variety of natural time scales involved in the plasma phenomenology. We have started developing a new approach to the global ionospheric specification called Real‐Time Assimilative Mapping (RTAM). The IRI‐RTAM will use data from the Global Ionospheric Radio Observatory (GIRO) to smoothly transform IRI's background empirical maps of the ionospheric characteristics to match the observations. Such empirical assimilative modeling will provide a high‐resolution, global picture of the ionospheric response to various short‐term events observed during periods of storm activity or the impact of gravity waves coupling the ionosphere to the lower atmosphere, including timelines of the vertical restructuring of the plasma distribution. It will also contribute to the challenging task of providing a rapid insight into the temporal and spatial space weather development using the real‐time GIRO data streams. The new assimilation technique “updates” the IRI electron density distribution while preserving the overall integrity of IRI's typical ionospheric feature representations. The technique adjusts the coefficients of the spherical/diurnal expansions used by the CCIR and URSI‐88 model to obtain the global subpeak electron density distribution. The set of global corrected coefficients can be generated as frequently as every 15 min and easily disseminated using a single real‐time RTAM server operated by GIRO.