Abstract:
Using IonPrfs of COSMIC (Constellation Observation System for Meteorology Ionosphere and Climate) measurements during 2006-2020 year, the temporal-spatial variation characteristics of ionosphere is analyzed over China region. Firstly, the quality of new generation COSMIC-2 data is introduced over China and global region. Then, the method of extracting the ionospheric characteristic parameters and controlling the quality of IonPrf products data is illustrated. Finally, the temporal-spatial variation characteristic of ionospheric parameters is analyzed over China region for 15 years during a complete solar cycle by different time scale. The result show: the ionospheric variation of China has the characteristic of annual, seasonal, and diurnal variation related to solar activity. In annual variation, NmF2, HmF2 and TEC in southern China being generally higher than those in northern China, has obvious spatial distribution characteristic. In seasonal variation, NmF2 and TEC have maximum in March and October, and minimum in June and July. The winter anomaly only appears in parts of southern China and the average of HmF2 in spring and autumn is higher than one in summer and winter. In diurnal variation, NmF2 and TEC have maximum during 12-16 LT(local time) and the local time corresponding to the peak value moves forward with increasing of latitude. The NmF2 and TEC are still high relatively after sunset during year of solar high activity. HmF2 of southern China having maximum during 12-16 LT and minimum during 5-7 LT. And HmF2 of northern China in daytime is generally lower than one in night.