Variations of ULF and VLF during moderate geomagnetic storm at equatorial region

Abstract

This paper presents variations of Ultra Low Frequency (ULF) and Very Low Frequency (VLF) during moderate geomagnetic storm using ground based observatories, Magnetic Data Acquisition System (MAGDAS)/Circum-Pan Magnetic Network (CPMN) magnetometer and Atmospheric Weather Electromagnetic System for Observation Modeling and Education (AWESOME) VLF receiver. In this analysis, the recorded ULF horizontal (H)-component are extracted from MAGDAS magnetometer at Yap Island (YAP), Federated States of Micronesia, Davao (DAV), Philippines, and Tirunelveli (TIR), India stations. VLF amplitude data were observed from VLF receiver at UKM while the transmitters are located at Katabomman (VTX), India, North West Cape (NWC), Australia and Lualualei, Hawaii (NPM), USA. The observations of the space weather conditions in this study are divided into two categories: quiet day (10 April 2010) and moderate geomagnetic storm (6 April 2010). The results show that the ULF and VLF variations are significantly affected during geomagnetic storm which geomagnetic activities are closely related with the solar parameters.