Simultaneous ground-based observations of electric and magnetic field variations near the magnetic equator for space weather study - Yumoto, Kiyohumi; Shinohara, Manabu; Nozaki, Kenro; Orosco, Erwin A.; Badillo, Victor; Bringas, Dennis; CPMN; WestPac Observation Groups (Proceedings of the 18th Samahang Pisika ng Pilipinas Physics Congress, 2000)