Applications Of Ice-cream Cone Model Of Coronal Mass Ejection In Space Weather

In this paper, the kinematic parameters (such as radial speed, angular width, and solar source region) of a number of CMEs (Coronal Mass Ejection) during Solar Cycle23are estimated from fitting the observational images of SOHO/Lasco in the sky-of-plane to an ice-cream cone model of CME.A number of SEP (Solar Energetic Particle) events during the year1998-2002are identified as well as their associated frontside CME events. For these CMES, the kinematic parameters inferred by the ice-cream cone model are analyzed for their correlation with characteristic times of intensity-time profiles of accompanying SEP events observed at1AU. Here the characteristic times is described as the onset time from accompanying CME eruption at the Sun to the SEP arrival at1AU, the rise time from the SEP onset to the time when the SEP intensity is one-half of peak intensity, and the duration time over which the SEP intensity is within a factor of2of the peak intensity. Though not significantly correlated with the SEP onset time, the radial speed and angular width of associated CMEs are significantly positive correlated with the SEP rise time and duration time when the SEP events are magnetically connected to the nearby longitude of the Earth. Our results suggest that a CME event with wider angular span and higher launch speed can more easily drive a strong and wide quasi-parallel shock nearby the Earth-connected interplanetary magnetic field lines, trap and accelerate particles for a longer time, and lead to longer rise time and duration time of ensuing SEP event.Ninety-three interplanetary shocks between January2000and May2005are selected from the observations of Wind and ACE spacecrafts. Their corresponding sources of CME are also identified from the observations of SOHO. The transit time of these CMEs from the Sun to the Earth are predicted using the Hakamada-Akasofu-Fry (HAF) model of solar wind. During the prediction, we use an ion-cream cone model to calculate the geometrical and kinematical parameters of these CMEs from the SOHO/LASCO observation in the sky of plane. Then, these parameters are inputted into the HAF model as proxies of the perturbation produced by these CMEs. The prediction results suggest that, the averaged absolute and relative errors of the Sun-Earth transit time between the predictions and observations are7.4hours and14.3%respectively. Sixty-three events (67.7%=63/93) are successfully predicted within the deviation of±8hours from observations. The averaged absolute error between the predictions and observations is relatively small, whose distribution is nearly to a Gaussian function centered at zero. These results substantiate that the methods used in this paper is relatively reliable for the prediction of Sun-Earth transit time of CME.