Real‐time shock arrival predictions during the “Halloween 2003 epoch”

Abstract

The “Halloween” epoch from 19 October to 20 November 2003 was marked by 19 major solar flares that were accompanied by metric type II radio bursts. Several of these flares were followed by major geomagnetic storms. The radio bursts were used in real time because they imply coronal and interplanetary transport. Most of these events were also associated with halo (or partial halo) coronal mass ejections (CMEs). A continuing, widely distributed, real‐time research project called “fearless forecasts,” using an ensemble of four physics‐based models, has been made of the ensuing shock arrival times since 1997 at the L1 libration point. Model inputs include consideration of the type II shock speed estimates above the flare sites as well as preliminary CME leading edge speeds in the plane of sky. Thus the model ensemble used inputs that were guided by both speed estimates. The rationale for using CME speeds includes the assumption that their high speeds represented the shocks themselves in addition to an assumption concerning their quasi‐sphericity as they left the Sun. We compare the shock arrival predictions to those observed by the solar wind and magnetic field monitors on the Advanced Composition Explorer (ACE) and the solar wind monitor on the Solar and Heliospheric Observatory (SOHO) satellite. Success rates of the models are provided as a metric for this kind of active epoch. These success rates are 79% for one of the considered models using a “hit” window of ±24 hours and 74% when ±15 hours was used. This model demonstrates the importance of simulating both nonhomogeneous background environments and complex shock interactions.

Three‐dimensional MHD Simulation of the 2003 October 28 Coronal Mass Ejection: Comparison with LASCO Coronagraph Observations

“…Liu & Hayashi (2006) modeled the CME eruption in the solar corona with density and pressure perturbations. Dryer et al (2004) and Wu et al (2005) both modeled CME-driven shock propagation and predicted the shock arrival times with reasonable success. This work that models a specific event marks a clear distinction from nonYevent-specific CME simulations (e.g., Usmanov & Dryer 1995;Riley et al 2002;Manchester et al 2004b;Jacobs et al 2007) and nonYeventspecific Sun-to-thermosphere space weather simulations modeled by the Center for Space Environment Modeling (CSEM; Tó th et al 2005) and the Center for Integrated Space Weather Modeling (CISM; Luhmann et al 2004).…”

The role of aerodynamic drag in propagation of interplanetary coronal mass ejections

“…Performances of these forecasting procedures were analyzed in a number of validation studies (e.g. Cho et al 2003;Dryer et al 2004;Oler 2004;McKenna-Lawlor et al 2006;Feng et al 2009;Smith et al 2009;Taktakishvili et al 2009), showing that the current prediction accuracy ranges around ±10 h and that sometimes errors can be even larger than one day.…”

Energetic particles detected by the Electron Reflectometer instrument on the Mars Global Surveyor, 1999–2006

“…[2] Successful modeling of the propagation and evolution of solar energetic particles (SEPs) and interplanetary coronal mass ejections (ICMEs) is on ongoing effort in the heliospheric community for both scientific and practical purposes [Akasofu, 2001;Dryer et al, 2004;Hakamada and Akasofu, 1982;Schwadron et al, 2010]. The impact of these extreme examples of space weather on the terrestrial environment is well known, and include communications and power disruptions, damage or even the total loss of satellites, increased magnetospheric and auroral activity, changes in atmospheric processes including chemistry, and increased exposure to individuals at high altitudes or in low-earth orbit [Baker, 2000;Dyer et al, 2003].…”