Longitudinal Structure of the Mid- and Low-Latitude Ionosphere Observed by Space-borne GPS Receivers

摘要: This study presents longitudinal structures of the mid- and low-latitude ionosphere using GPS radio occultation observation on board COSMIC satellite mission. The structure seen in equatorial ionospheric regions results from modification daily dynamo electric field by upward propagating atmospheric tides that are generated latent heat release tropical rainstorms. Changes modify plasma fountain thereby enhance ionization anomaly (EIA). With capability three-dimensional global observation, altitudinal, local time, monthly variations this recent discovered fascinating feature obtained for further understanding underlying physical mechanism. Through comparison between electron densities at various altitudes, is prominently upper part ionosphere. Additionally, observations provide Weddell Sea which featured greater nighttime density than daytime. Not only occurring southern hemisphere near region Antarctica, a similar enhancement also found northern during summer observations. anomalous signatures both hemispheres share very characteristics structure, latitudinal distribution, appearance time. They are, therefore, categorized as mid-latitude (MSNA).