Triple Ionosophere PhotoMeter onboard Fengyun-3E satellite: Data validation and ionosphere information extraction

Abstract

The Triple Ionosophere PhotoMeter (TRIPM) is designed to make the disk observations of the Earth airglow emissions at OI 135.6 nm and N2 Lyman-Birge-Hopfield (LBH) band that flew aboard the newly launched early morning satellite Fengyun-3E (FY-3E) which was launched on July 5th, 2021. This is the first attempt to obtain the global twilight airglow data in the far ultraviolet band using Ionosophere PhotoMeter. The seasonal behavior of the twilight airglow at the OI 135.6 nm and N2LBH band is exhibited and interpreted in the paper. Validity of the TRIPM data is analyzed by comparison with the simulation results of the Global Airglow (GLOW) and the simulation results reveal good consistency with the observational results. Furthermore, based on the ionospheric contributions calculated by GLOW model, we extract the ionospheric information from the TRIPM 135.6 nm emissions. This means the ionospheric signature in the 135.6 nm radiance at the dawn and dusk times can be provided. Comparison between the ionospheric 135.6 nm radiance due to O+ and electron radiative recombination with GPS TEC data shows a similar morphology of equatorial arcs and seasonal variation of the ionosphere. Plain Language SummarySome interesting twilight airglow distribution features at the OI 135.6 nm and N2LBH band are obtained by TRIPM instrument onboard FY-3E which is an excellent platform for observing the twilight glow. To interpret the measurements, model simulation results from GLOW model are used for comparison and validation with the measured data. The good consistency between the model and observational results serves as a prerequisite for the further application of the data. Furthermore, based on the ionospheric contributions calculated by GLOW model, the ionosphere contributions in the measured 135.6 nm emissions by TRIPM is separated from the data under a sunlit condition. the ionospheric 135.6 nm radiances due to O+ and electron radiative recombination at the dawn and dusk times, a valuable ionospheric product obtained, show a similar morphology of equatorial arcs and seasonal variation of the ionosphere.