Equatorial horizontal magnetic variability on hourly to monthly time scales / Siti Noor Aisyah Ahmad

This report discussed the variability of the earth horizontal magnetic field component, H on the hourly, daily and monthly timescales using the MAGnetic Data Acquisition System (MAGDAS) installed in the Langkawi Island, Malaysia. The variation of H shown in this study is selected on the 64 geomagnetically quietest days between January to December 2007. The measured H shows large hourly increase up several nT on the midday and relatively stable on the rest of hours of the day, the measured maximum daily H range between 40430 nT to 40550 nT. The mean H on the daily timescales is 40451 nT with standard deviation of 23.74 nT. The largest standard deviation in the 12 months was 30.752 nT on September with the mean of 40671.36 nT. There was no data observed on October, November and December of 2007. The hourly variability exhibits maximum H amplitude with the occurrence of the earth equatorial electrojet current (EEJ).