Specification and forecasting of the Earth’s ionosphere and thermosphere (IT) is of critical importance owing to its impact on, for example, navigation signals (e.g., GPS) and satellite orbital drag. Following the path of troposphere numerical weather prediction, the IT community has recently adopted data assimilation techniques in order to improve specification and forecast capabilities. In addition to operational space weather applications, data assimilation models are a valuable tool for addressing fundamental IT scientific questions. In particular, physics-based data assimilation models enable investigation of the predictability of the IT system, including the physical mechanisms controlling the predictability. By providing the best estimate of the IT state, data assimilation models further enable improved understanding of the processes driving IT variability, making them a valuable resource for the scientific community.
Data assimilation in the IT is a relatively recent endeavor, and the methodologies remain relatively immature with a variety of different approaches taken by different researchers. Furthermore, the capabilities of data assimilation models to investigate the predictability of the IT have yet to be fully exploited. We propose to bring together experts in data assimilation, numerical modeling, and observations in order to: (1) investigate the predictability of the IT, and (2) improve current IT data assimilation techniques. The predictability of the IT system has yet to be fully explored, making it an important, unresolved, scientific question. Aspects of the IT predictability will be investigated through detailed event studies, enhancing scientific understanding of both IT predictability as well as the advantages and disadvantages of different data assimilation techniques. Through comparison of different data assimilation techniques, we will develop an in-depth understanding of the optimal approaches for IT data assimilation. The ISSI will additionally provide a forum for the development and exchange of IT specific data assimilation algorithms. It is critical for such a forum to take place now given the recent availability of abundant new IT observations from the COSMIC-2, GOLD, and ICON missions.
July 4-8, 2022 – First team meeting at ISSI-Bern
Summer 2023 – Second team meeting at ISSI-Beijing