Sains Malaysiana 48(11)(2019): 2427–2435

http://dx.doi.org/10.17576/jsm-2019-4811-13

Geomagnetic Phenomena Observed by a Temporal Station at Ulu-Slim, Malaysia during the Storm of March 27, 2017

(Fenomena Geomagnetik yang Dicerap oleh Stesen Temporal di Ulu-Slim, Malaysia semasa Ribut pada 27 Mac 2017)

ARAFA-HAMED, T.¹, KHALIL, A.²*, NAWAWI, M.², HASSAN, H.³ & M.H. ARIFIN⁴

¹National Research Institute of Astronomy and Geophysics (NRIAG), Egypt

²School of Physics, Universiti Sains Malaysia, 11800 USM, Pulau Pinang, Malaysia

³Geology Department, Faculty of Science, Helwan University, Egypt

⁴Program Geologi, Pusat Sains Bumi dan Alam Sekitar, Fakulti Sains dan Teknologi, Universiti Kebangsaan Malaysia, 43600 UKM Bangi, Selangor Darul Ehsan, Malaysia

Diserahkan: 7 April 2019/Diterima: 15 Ogos 2019

ABSTRACT

A 3-axis fluxgate magnetometer was temporally setup for continuous recording during March 2017 at 3о 54’ 6” N, 101о 29’ 41” E, Ulu-Slim, Malaysia. On March 27th, a magnetic storm has been triggered by energetic solar wind emitted from a coronal hole on the sun that impacted the magnetosphere until the end of the measurement campaign on March 29th. The values measured at a sampling rate of 600 Hz are averaged to get a 1 Hz record from March 26 16:00 LT to March 29 12:00 LT. The 1 second data set is studied to deduce all magnetic phenomena captured during the magnetic storm. An overview of the complete record indicates the start of the storm and a complete absence of the typical diurnal variation of the total-field intensity on March 28. The diurnal variations are eliminated by subtracting a moving average of 100 samples from the recorded values. The residual shows a clear amplification of pulsations with the start of the storm. Pulsations enhancement are common around noon and is continuous on March 28th due to magnetotail activities during local night. Magnetospheric breathing as compression and expansion of the magnetosphere at long periods of 20 to 40 min is captured twice during the storm. An obvious occurrence of magnetotail reconnection is deduced by a sudden, steep increase of the total magnetic field with 50 nT at 01:30 LT on March 28. We conclude that the continuous recording of the magnetic field components provides very useful information about what processes are ongoing in space and how it might affect the logistics on the ground. The implementation of similar magnetometers as continuous observation stations would be of crucial benefits for Malaysia in both basic scientific and environmental aspects.

Keywords: Coronal hole; geomagnetic storm; magnetospheric processes

ABSTRAK

Meter Magnet fluxgate 3-paksi telah didirikan untuk rakaman berterusan pada Mac 2017 di 3° 54’ 6” U, 101° 29’ 41” T, Ulu-Slim, Malaysia. Pada 27 Mac, ribut magnet telah dicetuskan oleh angin suria bertenaga yang dipancarkan daripada lubang korona di matahari yang memberi kesan kepada magnetosfera sehingga berakhirnya kempen pengukuran pada 29 Mac. Nilai-nilai yang diukur pada kadar persampelan 600 Hz adalah untuk mendapatkan rekod purata 1 Hz dari 26 Mac 16:00 waktu tempatan hingga 29 Mac 12:00 waktu tempatan. Set data 1 saat dikaji untuk menyimpulkan semua fenomena magnet yang direkod semasa ribut magnet. Gambaran keseluruhan rekod lengkap menandakan permulaan ribut dan ketiadaan lengkap variasi diurnal yang tipikal daripada keamatan keseluruhan medan pada 28 Mac. Variasi diurnal dihapuskan dengan menolak purata bergerak 100 sampel daripada nilai yang direkodkan. Baki menunjukkan penguatan denyutan yang jelas dengan permulaan ribut. Peningkatan pulsasi adalah umum sekitar tengah hari dan berterusan pada 28 Mac disebabkan aktiviti ekor magnet semasa malam tempatan. Pernafasan magnetosfera sebagai mampatan dan pengembangan magnetosfera pada masa yang panjang iaitu 20 hingga 40 min direkodkan dua kali semasa ribut. Satu kejadian yang jelas mengenai penyambungan semula ekor magnet disimpulkan oleh peningkatan mendadak daripada medan magnet keseluruhan dengan 50 nT pada 01:30 waktu tempatan pada 28 Mac. Kami menyimpulkan bahawa rakaman berterusan komponen magnetik menyediakan maklumat yang sangat berguna tentang apa proses yang berterusan dalam ruang dan bagaimana ia boleh mempengaruhi logistik di lapangan. Pengukuran meter magnet yang sama sebagai stesen pemerhati yang berterusan akan menjadi manfaat penting bagi Malaysia dalam kedua-dua aspek asas saintifik dan alam sekitar.

Kata kunci: Lubang korona; proses magnetosfera; ribut geomagnet

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*Pengarang untuk surat-menyurat; email: amin_khalil@usm.my