Using heliospheric imaging observations to forecast the arrival time of CMEs
Abstract
The estimation of arrival time of coronal mass ejections (CMEs) near 1 AU is a crucial problem in the development of any space weather prediction model. For more than twenty years such studies are being done mainly using coronagraphs (SOHO/LASCO) observations near the sun or using empirical, statistical or numerical arrival time models. In both the approaches, we utilize the in-situ measurements of ICMEs as a reference of the actual arrival time of CMEs. But the identification of ICMEs near the earth is based on many signatures and they usually have unclear boundaries, resulting in uncertainties in the actual arrival time too. In this way, our understanding about CME kinematics and estimation of its arrival time based on two point measurements, are not sufficient. In order to understand the CME kinematics throughout the interplanetary medium, we have analyzed the coronagraph (2.5 -15 Rs) and heliospheric imager (15-330 Rs) (SECCHI/HI) data. We applied different methods on imaging (COR and HI) observations to estimate the true kinematics of CMEs in interplanetary medium. We used these estimates as inputs to the drag based model to predict the arrival time as well as transit velocity of CMEs at 1 AU. We also compare the accuracy of different methods implemented on imaging (COR and HI) data on our studied events. Our analysis reveals the importance of heliospheric imager observations in forecasting the CME arrival time near 1 AU.
- Publication:
-
Astronomical Society of India Conference Series
- Pub Date:
- 2013
- Bibcode:
- 2013ASInC...9...70M