Prediction of shock arrival time at the Earth by the STOA-2 model
Abstract
We have examined a possibility for improvement of the STOA (Shock Time Of Arrival) model for interplanetary shock propagation. In the STOA model, the shock propagating velocity is given by VsR-N with N=0.5, where R is the heliocentric distance. Noting observational and numerical findings that the radial dependence of shock wave velocity depends on initial shock wave velocity, we suggest a simple modified STOA model (STOA-2) which has a linear relationship between initial coronal shock wave velocity (Vis ) and its deceleration exponent(N), N = 0.05 + 4 × 10-4 Vis , where Vis is a numeric value expressed in units of km s-1 . Our results show that the STOA-2 model not only removes a systematic dependence of the transit time difference predicted by the previous STOA model on initial shock velocity, but also reduces the number of events with large transit time differences.
- Publication:
-
34th COSPAR Scientific Assembly
- Pub Date:
- 2002
- Bibcode:
- 2002cosp...34E.472M