Longitudinal Differences in the Low-latitude Ionosphere and in the Ionospheric Variability

Larisa P Goncharenko, MIT Haystack Observatory, Westford, United States, Shunrong Zhang, MIT Haystack Observatory, Westford, MA, United States, Huixin Liu, Kyushu University, Fukuoka, Japan, Takuya Tsugawa, NICT National Institute of Information and Communications Technology, Tokyo, Japan, Inez Staciarini Batista, INPE, Sao Jose Dos Campos, Brazil and Bodo W Reinisch, Lowell Digisonde International, Lowell, MA, United States