摘要： As described in a previous paper, a three‐dimensional ionospheric electron density (Ne) model has been constructed from vertical Ne profiles retrieved from the FormoSat3/Constellation Observing System for Meteorology, Ionosphere, and Climate GPS radio occultation measurements and worldwide ionosonde foF2 and foE data and named the TaiWan Ionospheric Model (TWIM). The TWIM exhibits vertically fitted α‐Chapman‐type layers with distinct F2, F1, E, and D layers, and surface spherical harmonic approaches for the fitted layer parameters including peak density, peak density height, and scale height. To improve the TWIM into a real‐time model, we have developed a time series autoregressive model to forecast short‐term TWIM coefficients. The time series of TWIM coefficients are considered as realizations of stationary stochastic processes within a processing window of 30 days. These autocorrelation coefficients are used to derive the autoregressive parameters and then forecast the TWIM coefficients, based on the least squares method and Lagrange multiplier technique. The forecast root‐mean‐square relative TWIM coefficient errors are generally <30% for 1 day predictions. The forecast TWIM values of foE and foF2 values are also compared and evaluated using worldwide ionosonde data. Key Points A time series autoregressive model was developed to forecast the ionosphereThe 3‐D and global TaiWan Ionospheric Model (TWIM) was improved to be real timeThe TWIM exhibits vertical Chapman layers and horizontal spherical harmonics 其他題名： Radio Sci 出版者： Washington: Blackwell Publishing Ltd 出版日期： 2014-10 出處： Radio science, 2014-10, Vol.49 (10), p.977-986 資源來源： Wiley Online Library - AutoHoldings Journals 版權： 2014. American Geophysical Union. All Rights Reserved. 識別號： ISSN: 0048-6604 識別號： ISSN: 1944-799X 識別號： EISSN: 1944-799X 識別號： DOI: 10.1002/2014RS005448
