Coronal Hole and Geomagnetic Disturbance

Seminar Nasional Sains Antariksa V ISBN: 978-979-1458-43-6
Serpong, 15 November 2010
Geomagnet dan Teknologi Landas Bumi

KAITAN GANGGUAN GEOMAGNET DENGAN
LUBANG KORONA
Mamat Ruhimat dan Clara Y. Yatini
Pusat Pemanfaatan Sains Antariksa LAPAN
e-mail: ruhimat@bdg.lapan.go.id

Abstract
We analyzed two geomagnetic disturbances which are derived from the measurement of
daily variation of geomagnetic field conducted in BMKG Tondano Manado observatory (1.30°North, 124.93° East), particularly in Horizontal (north-south) component. The first occurred subsequently on August 24 and 25, 2010, while the second occurred on September 24, 2010.
The decreases of the intensity of Horizontal component reached minimum in August 25 and September 24, 2010 with intensities -55 nT and -40 nT respectively. By analyzing the solar and interplanetary activity a few days before the appearance of the geomagnetic disturbances, we found that those disturbances are related with the existence of geoeffective coronal holes.

Keywords: Coronal hole and geomagnetic disturbance