DETERMINATION OF PC5 MAGNETIC PULSATION INDEX IN INDONESIA

• Main Author: BANGKIT ( NIM : 22412018 ); Pembimbing : Afnimar, Ph.D, HARRY
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/18603
• Institution: Institut Teknologi Bandung

Pc5 magnetic pulsation is a kind of hydromagnetic oscillation in the Earth’s magnetosphere where those oscillations are contained in the geomagnetic field variations. Occurrence of the magnetic pulsations is believed depend on solar wind and magnetosphere dynamics. Previous studies show that Pc5 magnetic pulsations can be used to estimated solar wind parameters. In this study the Butterworth filter has been applied to extract Pc5 pulsation in the range of period 150-600 seconds from ground-based magnetic field variation at Biak station during 1992-2003. Pc5 index was constructed quasi-logarithmically where global magnetospheric index, Kp, has been used our reference and best correlation between Pc5 and Kp index was found for minimum threshold of Pc5 amplitude at 0.0319 nT. In the range of Pc5 index, 0 to 4+, solar wind velocity as well as its dynamic pressure showed linear relations with our Pc5 index. Unfortunately, we cannot perform detail analyses the relation of solar wind velocity/dynamic pressure and Pc5 pulsation in the range of index larger than 4+ since poor of number of events. That was occured because during large magnetic storm or high speed solar wind the magnetometer in Biak sometimes saturated. The Pc5 index that defined from Biak data has been also applied for magnetic data at Manado, Pare-Pare, Kupang, Tanjungsari and Kototabang and we found that also have good relation with magnetic storm activity and solar wind velocity as well as its dynamic pressure. Hence, we concluded that our Pc5 index that derived from ground-based station at Biak can be used for another stations in Indonesia and also reliable for monitoring of magnetic storm activity and to estimate solar wind speed as well as its dynamic pressure.