Mapping the East African Ionosphere Using Ground-based GPS TEC Measurements

Mengist, Chalachew Kindie; Kim, Yong Ha; Yeshita, Baylie Damtie; Workayehu, Abiyot

doi:10.5140/jass.2016.33.1.29

Cited by 5 publications

(1 citation statement)

References 8 publications

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“…Geomagnetic storms have an impact on communications, global positioning system (GPS), satellites, geological exploration, electrical power grids, geomagnetically induced currents (GICs), and steel cables. As society continues to rely on these systems, more effort is being exerted to prevent damage from geomagnetic storms (Ahn 2000;Choi et al 2005;Choi et al 2015;Chung et al 2015;Mengist et al 2016). To reduce damage caused by geomagnetic storms resulted from halo CMEs impacting Earth, domestic and international space weather institutes provide CME lists.…”

Section: Introductionmentioning

confidence: 99%

Auto-detection of Halo CME Parameters as the Initial Condition of Solar Wind Propagation

Choi¹,

Park²,

Kim³

2017

Journal of Astronomy and Space Sciences

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Halo coronal mass ejections (CMEs) originating from solar activities give rise to geomagnetic storms when they reach the Earth. Variations in the geomagnetic field during a geomagnetic storm can damage satellites, communication systems, electrical power grids, and power systems, and induce currents. Therefore, automated techniques for detecting and analyzing halo CMEs have been eliciting increasing attention for the monitoring and prediction of the space weather environment. In this study, we developed an algorithm to sense and detect halo CMEs using large angle and spectrometric coronagraph (LASCO) C3 coronagraph images from the solar and heliospheric observatory (SOHO) satellite. In addition, we developed an image processing technique to derive the morphological and dynamical characteristics of halo CMEs, namely, the source location, width, actual CME speed, and arrival time at a 21.5 solar radius. The proposed halo CME automatic analysis model was validated using a model of the past three halo CME events. As a result, a solar event that occurred at 03:38 UT on Mar. 23, 2014 was predicted to arrive at Earth at 23:00 UT on Mar. 25, whereas the actual arrival time was at 04:30 UT on Mar. 26, which is a difference of 5 hr and 30 min. In addition, a solar event that occurred at 12:55 UT on Apr. 18, 2014 was estimated to arrive at Earth at 16:00 UT on Apr. 20, which is 4 hr ahead of the actual arrival time of 20:00 UT on the same day. However, the estimation error was reduced significantly compared to the ENLIL model. As a further study, the model will be applied to many more events for validation and testing, and after such tests are completed, on-line service will be provided at the Korean Space Weather Center to detect halo CMEs and derive the model parameters.

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