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Real-time Information

We operate two types of GAIA real-time simulation:

【① Quasi-real-time and forecast simulation】

This simulation provides current status and forecast information for about two days ahead regarding upper atmospheric conditions affected by variations in the lower atmosphere and sunlight.

Disturbances in the lower atmosphere are taken into account by inputting the Japan Meteorological Agency's reanalysis data (JRA), and changes in solar radiations are given using the F10.7 index based on solar radio wave intensity observations at a wavelength of 10.7 cm. This simulation results are updated once a day. Electric field and auroral particle precipitation in the polar regions are kept constant for this simulation. (See [1][2] for details)

【② Real-time polar-variable simulation】

This simulation provides current status and approximately 40-minute forecast information on upper atmospheric conditions caused by variations in the lower atmosphere, sunlight, and solar wind.

In addition to the inputs used in the calculations in ①, this simulation additionally inputs real-time solar wind data observed by DSCOVR satellite and performs simulations by changing the polar electric field and auroral particle precipitation using an empirical model. In addition to updating the Japan Meteorological Agency reanalysis data and the F10.7 index once a day, simulation and results are updated from time-to-time reflecting updates of solar wind observation data. Ionospheric storms occur in this simulation in response to solar wind variations. (See [1][3] for details)

Table 1. Two types of GAIA real-time simulation
Main model inputs Lead-time Updates
Sunlight Lower atmospheric variation Polar input
① Quasi-real-time and forecast simulation Variable Variable Fix 1―2 day Once/day
② Real-time polar-variable simulation Variable Variable Variable ~40 min. Updated from time to time

References

[1] Jin, H. and C. Tao (2021), “2-3 Global atmosphere-ionosphere simulation”, NICT research report, Vol 67, No. 1, p29-37. https://www.nict.go.jp/publication/shuppan/kihou-journal/houkoku67-1_HTML/2021S-02-03.pdf (in Japanese)
[2] Tao, C., H. Jin, Y. Miyoshi, H. Shinagawa, H. Fujiwara, M. Nishioka, and M. Ishii (2020), "Numerical forecast of the upper atmosphere and ionosphere using GAIA", Earth Planets Space, 72:178, https://doi.org/10.1186/s40623-020-01307-x.
[3] Kataoka, R., D. Shiota, H. Fujiwara, H. Jin, C. Tao, H. Shinagawa, and Y. Miyoshi (2022), Unexpected space weather causing the reentry of 38 Starlink satellites in February 2022, Journal of Space Weather and Space Climate, DOI: 10.1051/swsc/2022034. https://www.swsc-journal.org/articles/swsc/full_html/2022/01/swsc220018/swsc220018.html