Sounding of sporadic E layers from China Seismo-Electromagnetic Satellite (CSES) radio occultation and comparing with ionosonde measurements

[摘要] GNSS radio occultation (RO) plays an important role inionospheric electron density inversion and sounding of sporadic E layers. AsChina's first electromagnetic satellite, China Seismo-ElectromagneticSatellite (CSES) has collected the RO data from both GPS and BDS-2satellites since March 2018. In this study, we extracted the signal-to-noiseratio (SNR) data of CSES and calculated the standard deviation of normalizedSNR. A new criterion is developed to determine the E s events, that is, whenthe mean value of the absolute value of the difference between thenormalized SNR is greater than 3 times the standard deviation. Thestatistics show that sporadic E layers have strong seasonal variations withhighest occurrence rates in summer season at middle latitudes. It is alsofound that the occurrence height of E s is mainly located at 90–110 km, andthe period 14:00–20:00 LT is the high incidence period of E s . Inaddition, the geometric altitudes of a sporadic E layer detected in CSESradio occultation profiles and the virtual heights of a sporadic E layerobtained by the Wuhan Zuoling station (ZLT) ionosonde show three differentspace-time matching criteria. Our results reveal that there is a goodagreement between both parameters which is reflected in the significantcorrelation.

[学科分类] 化学工程（综合）