Forecasting the IMF Bz Component at 1 AU during the passage of ICMEs: An Assessment and Extension of the Savani Approach
Abstract
The z-component of the interplanetary magnetic field (Bz) fluctuates in complex, and arguably, unpredictable ways. However, the ability to be able to forecast its behavior over the next 24 hours, or further into the future, is a crucial requirement for Space Weather Centers. A previous study by Savani et al. (2015) has suggested that such forecasts may be possible, at least during intervals marking the passage of magnetic clouds past the Earth. However, only a handful of carefully-selected events were chosen, undoubtedly positively biasing the interpretation of the results. In this study, we develop a prototype prediction chain, based on, but extending Savani et al."s approach. We break the inner heliosphere into three distinct regions and apply different models/techniques to each. First, from the Sun to 30Rs, we explore a variety of approaches for determining the initial orientation of the flux rope, which is presumed to lie within the erupting CME. Second, we use a selection of'cone model' fits for the erupting ejecta, to infer their kinematic and geometric properties. Third, we apply various propagation models to convey the properties of the ICME from the high corona to 1 AU. We apply this procedure to a number of well-observed and studied CMEs to determine: (1) Which combination of techniques appears to work the best; (2) Under what conditions useful predictions can be made; and (3) what are the likely uncertainties with these predictions.
- Publication:
-
Solar Heliospheric and INterplanetary Environment (SHINE 2016)
- Pub Date:
- July 2016
- Bibcode:
- 2016shin.confE..56R