scholarly journals EFEK CME HALO PENUH PADA IONOSFER LINTANG RENDAH DARI DATA GPS BAKO DI CIBINONG [EFFECT OF FULL HALO CME ON LOW LATITUDE IONOSPHERE FROM BAKO GPS DATA IN CIBINONG]

2018 ◽  
Vol 15 (1) ◽  
pp. 51
Author(s):  
Fakhrizal Muttaqien ◽  
Buldan Muslim

A full halo coronal mass ejections (CMEs) are most energetic solar events that eject huge amount of mass and magnetic fields into heliosphere with 360o angular angle. The full halo CME effect on the ionosphere can be determined from the ionospheric total electron content (TEC) derived from GPS data. GPS data from BAKO station in Cibinong, satellite orbital data (brcd files) and intrumental bias data (DCB files) have been used to obtain TEC using GOPI software. Analysis of  the full halo CME data, Dst index, and TEC during October 2003 and February 2014 showed that the full halo CME could cause ionospheric disturbances called ionospheric storms. Magnitude and time delay of the ionospheric storms  depended on the full halo CME speed. For the high-speed full halo CME, the negative ionospheric storm generally occured during recovery phase of the geomagnetic storm. When the initial phase of geomagnetic disturbance with increasing Dst index more than +30 nT, the ionospheric storm occured during main phase of geomagnetic disturbance although the main phase of geomagnetic disturbance did not reach geomagnetic storm condition. ABSTRAKCoronal mass ejection  (CME) halo penuh merupakan peristiwa matahari  berenergi tinggi, yang menyemburkan massa dan medan magnet ke heliosfer dengan sudut angular sebesar 360º. Efek  CME halo penuh pada ionosfer dapat diketahui dari Total Electron Content (TEC). Data GPS BAKO di Cibinong, data orbit satelit (file brcd) dan data bias instrumental (file DCB) dapat digunakan untuk penentuan TEC menggunakan software GOPI. Analisis data CME halo penuh, indeks Dst, dan TEC selama bulan Oktober 2003 dan Februari 2014 menunjukkan bahwa CME halo penuh dapat menimbulkan gangguan ionosfer yang disebut badai ionosfer. Besar dan selang waktu badai ionosfer setelah terjadinya CME, tergantung pada kelajuan CME halo penuh. Untuk CME halo penuh berkelajuan tinggi, badai ionosfer negatif umumnya terjadi pada fase pemulihan badai geomagnet. Jika fase awal gangguan geomagnet diawali dengan peningkatan indeks Dst melebihi +30 nT, maka badai ionosfer dapat terjadi pada fase utama gangguan geomagnet walau gangguan geomagnet setelah  fase awal tidak mencapai kondisi badai geomagnet. 

2004 ◽  
Vol 6 (5) ◽  
pp. 339-354 ◽  
Author(s):  
E. L. Afraimovich ◽  
E. I. Astafieva ◽  
M. B. Gokhberg ◽  
V. M. Lapshin ◽  
V. E. Permyakova ◽  
...  

2017 ◽  
Vol 35 (6) ◽  
pp. 1309-1326 ◽  
Author(s):  
Patricia Mara de Siqueira Negreti ◽  
Eurico Rodrigues de Paula ◽  
Claudia Maria Nicoli Candido

Abstract. Total electron content (TEC) is extensively used to monitor the ionospheric behavior under geomagnetically quiet and disturbed conditions. This subject is of greatest importance for space weather applications. Under disturbed conditions the two main sources of electric fields, which are responsible for changes in the plasma drifts and for current perturbations, are the short-lived prompt penetration electric fields (PPEFs) and the longer-lasting ionospheric disturbance dynamo (DD) electric fields. Both mechanisms modulate the TEC around the globe and the equatorial ionization anomaly (EIA) at low latitudes. In this work we computed vertical absolute TEC over the low latitude of South America. The analysis was performed considering HILDCAA (high-intensity, long-duration, continuous auroral electrojet (AE) activity) events and geomagnetic storms. The characteristics of storm-time TEC and HILDCAA-associated TEC will be presented and discussed. For both case studies presented in this work (March and August 2013) the HILDCAA event follows a geomagnetic storm, and then a global scenario of geomagnetic disturbances will be discussed. Solar wind parameters, geomagnetic indices, O ∕ N2 ratios retrieved by GUVI instrument onboard the TIMED satellite and TEC observations will be analyzed and discussed. Data from the RBMC/IBGE (Brazil) and IGS GNSS networks were used to calculate TEC over South America. We show that a HILDCAA event may generate larger TEC differences compared to the TEC observed during the main phase of the precedent geomagnetic storm; thus, a HILDCAA event may be more effective for ionospheric response in comparison to moderate geomagnetic storms, considering the seasonal conditions. During the August HILDCAA event, TEC enhancements from  ∼  25 to 80 % (compared to quiet time) were observed. These enhancements are much higher than the quiet-time variability observed in the ionosphere. We show that ionosphere is quite sensitive to solar wind forcing and considering the events studied here, this was the most important source of ionospheric responses. Furthermore, the most important source of TEC changes were the long-lasting PPEFs observed on August 2013, during the HILDCAA event. The importance of this study relies on the peculiarity of the region analyzed characterized by high declination angle and ionospheric gradients which are responsible for creating a complex response during disturbed periods.


2019 ◽  
Vol 94 ◽  
pp. 05005 ◽  
Author(s):  
Mokhamad Nur Cahyadi ◽  
Almas Nandityo Rahadyan ◽  
Buldan Muslim

Ionosphere is part of the atmospheric layer located between 50 to 1000 km above the earth's surface which consists of electrons that can influence the propagation of electromagnetic waves in the form of additional time in signal propagation, this depends on Total Electron Content (TEC) in the ionosphere and frequency GPS signal. In high positioning precision with GPS, the effect of the ionosphere must be estimated so that ionospheric correction can be determined to eliminate the influence of the ionosphere on GPS observation. Determination of ionospheric correction can be done by calculating the TEC value using dual frequency GPS data from reference stations or models. In making the TEC model, a polynomial function is used for certain hours. The processing results show that the maximum TEC value occurs at noon at 2:00 p.m. WIB for February 13, 2018 with a value of 35,510 TECU and the minimum TEC value occurs in the morning at 05.00 WIB for February 7, 2018 with a value of 2,138 TECU. The TEC model spatially shows the red color in the area of Surabaya and its surroundings for the highest TEC values during the day around 13.00 WIB to 16.00 WIB.


2015 ◽  
Vol 640 ◽  
pp. 012072 ◽  
Author(s):  
P K Purohit ◽  
Azad A Mansoori ◽  
Parvaiz A Khan ◽  
Roshni Atulkar ◽  
Purushottam Bhawre ◽  
...  

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