Simultaneous ground-based observations of electric and magnetic field variations near the magnetic equator for space weather study

Authors

Kiyohumi Yumoto Department of Earth and Planetary Sciences, Kyushu University, Japan
Manabu Shinohara Solar-Terrestrial Environment Laboratory, Nagoya University, Japan
Kenro Nozaki Communications Research Laboratory, Tokyo, Japan
Erwin A. Orosco Department of Physics, University of San Carlos, Philippines
Victor Badillo, SJ Manila Observatory, Ateneo de Manila University, Philippines
Dennis Bringas Muntinlupa Magnetic Observatory, National Mapping and Resource Information Authority, Philippines
CPMN and WestPac Observation Groups Space Environment Research Center, Kyushu University, Japan

Abstract

It is well known that daytime DP 2 magnetic variations observed on the ground are well correlated with changes of the solar wind Bz component (Nishida 1968a & b). Electric fields caused by the solar wind interaction with the Earth's magnetic field are believed to be imposed on the polar ionosphere and penetrate into the equatorial ionosphere (Nishida 1968b; Kikuchi, et al. 1996). DP 2 magnetic variations in the daytime are clearly seen on the ground in the equatorial region where the ionospheric Cowling conductivity is zonally enhanced, while those in the nighttime are difficult to be observed because ofthe lower ionospheric conductivity. The dip equator is a peculiar region where the ionospheric conductivity is much larger than those at low latitudes, and therefore DP 2 phenomena observed near the dayside dip equator can be a useful tool for monitoring the change of the interplanetary magnetic field (IMF) in the solar wind.
In order to clarify the global nature of penetration mechanism of DP 2 electric fields from the polar to the equatorial ionosphere, and to understand the solar wind-Earth's magnetosphere coupling as a space weather study, we have carried out simultaneous magnetic and electric field observations using the Circum-pan Pacific Magnetometer Network (CPMN; Yumoto, et al. 1996; Tachihara, et al. 1996; see the website of http://denjil02.geo.kyushu-u.ac.jp/denji/obs/obs_e.html) and the Frequency Modulated-Continuous Wave (FM-CW) HF radar (Nozaki, et al. 1999).

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Issue

2000: Proceedings of the 18th Samahang Pisika ng Pilipinas Physics Congress

Article ID

SPP-2000-ID-12

Section

Interdisciplinary Studies

Published

2000-10-27

How to Cite

[1]

K Yumoto, M Shinohara, K Nozaki, EA Orosco, V Badillo, D Bringas, and CPMN and WestPac Observation Groups, Simultaneous ground-based observations of electric and magnetic field variations near the magnetic equator for space weather study, Proceedings of the Samahang Pisika ng Pilipinas 18, SPP-2000-ID-12 (2000). URL: https://proceedings.spp-online.org/article/view/SPP-2000-ID-12.