# Advances in Ionospheric Space Weather by Using FORMOSAT-7/COSMIC-2 GNSS Radio Occultations
## 6 Discussion and Summary
At NOAA/SWPC, the GloTEC that are generated by assimilating both F7/C2 RO measurements and GNSS TEC have become a useful tool to support the alerts and warnings issued by space weather forecasters. In addition to such dedicated centers offering daily ionosphere maps, there are also ongoing efforts to assimilate the F7/C2 RO measurements to improve the performance of physics-based models [121; 122]. Another major source of daily 3D electron density profiles is the GIS electron density constructed by assimilating F7/C2 RO and ground-based GNSS slant TECs [61; 62; 64]. GIS provides global electron density profiles at every hour with 20 km altitude resolution and \(2.5^{\circ}\times 5^{\circ}\) in latitude and longitude spacing. The GIS electron density has been used to examine ionosphere variations during magnetic storms [69] and electron density modulations during SSW [68], and to examine day-to-day ionosphere variability [67]. In summary, the GNSS RO soundings have revolutionized ionospheric research ever since the launch of F3/C satellites. The current F7/C2 mission, with even denser observations at the low-latitude region, offers more detailed electron density variations and near-real-time plasma irregularity monitoring capability to open up numerous opportunities in advancing space weather research. Furthermore, the F7/C2 measurements greatly contribute to constructing daily 3D global electron density maps to provide realistic and near-real-time electron density distribution. The additional advantages of the denser F7/C2 samplings demonstrated here shows that extending similar measurements to cover mid- to high-latitude regions in the future and also allowing for extended altitude coverage would extremely benefit global ionospheric investigations and help to further advance the ongoing modeling and forecast efforts. In conclusion, the GNSS RO observations offer a promising era for ionosphere space weather, especially as we are approaching another solar maximum. The following supporting information can be downloaded at: [[https://www.mdpi.com/article/10.3390/atmos13060858/s1](https://www.mdpi.com/article/10.3390/atmos13060858/s1)]([https://www.mdpi.com/article/10.3390/atmos13060858/s1](https://www.mdpi.com/article/10.3390/atmos13060858/s1)). Movie S1: Movie showing the 3D electron density structures similar to Figure 2, but for each month at each UT hour; Movie S2: Movie showing local-time maps of EIA evolution similar to Figure 3, but for each month. Conceptualization, J.-Y.L. ; J.-Y.L., C.-H.L., P.K.R., C.-Y.L., F.-Y.C., I.-T.L., T.-W.F., D.F.-R., S.-P.C. equally contribute to all other aspects. All authors have read and agreed to the published version of the manuscript. This study was supported by the Taiwan Ministry of Science and Technology grant MOST 108-2119-M-008-001. This work was financially supported by the Center for Astronautical Physics and Engineering (CAPE) from the Featured Area Research Center program within the framework of Higher Education Sprout Project by the Ministry of Education (MOE) in Taiwan. The FORMOSAT-3/COSMIC (F3/C) and FORMOSAST-7/COSMIC-2 (F7/C2) data used in this study were retrieved from Taiwan Analysis Center for COSMIC (TACC, [[https://tacc.cwb.gov.tw/v2/download.html](https://tacc.cwb.gov.tw/v2/download.html)]([https://tacc.cwb.gov.tw/v2/download.html](https://tacc.cwb.gov.tw/v2/download.html)), accessed on 1 May 2022). The authors acknowledge the Taiwan Ministry of Science and Technology and the Center for Astronautical Physics and Engineering (CAPE) supported by the Ministry of Education (MOE) of Taiwan for supporting this study. The authors also acknowledge the Taiwan Analysis Center for COSMIC (TACC) for the FORMOSAT-3/COSMIC (F3/C) and FORMOSAST-7/COSMIC-2 (F7/C2) data used in this study. The authors declare no conflict of interest.