The electromagnetic emissions and plasma modulations at middle latitudes related to SURA-CSES experiments in 2018

A total of 17 SURA-China Seismo-Electromagnetic Satellite (CSES) experiments in 2018 have been summarized and analyzed in multiple parameters detected in the topside ionosphere at altitude of 507 km from CSES. Most of them were fulfilled with underdense heating condition, and no any artificial density duct had been detected onboard CSES, but some plasma perturbations were actually observed in lower and topside ionosphere. Among them, different modulated waves were also transmitted by [power on, power off] and amplitude modulation modes on the pumping high-frequency (HF) wave from SURA, and some were illustrated in HF electric field from CSES in local nighttime, one being verified at fmod in single component of very low frequency (VLF) electric field in local daytime. In addition, X mode-emited HF waves excited a filamentary structure on the existing VLF transmitters in local daytime, being different with those in O-mode HF waves to enhance the VLF transmitter signals and widen their frequency band in local nighttime. These phenomena and their coupling process were discussed finally on the interaction of radio waves with plasma parameters in ionosphere.