Observations and numerical simulations of gradual SEP events with Ulysses and ACE

We study the latitudinal extent of the gradual solar energetic particle (SEP) events of 2000 June 10 and 2001 December 26 using energetic electron observations from the ACE and Ulysses. We investigate the effects of particle source and transport on the profiles. We get the best fit parameters for simulations by comparing simulations with the two spacecraft observations. We show that perpendicular diffusion can significantly affect the propagation of particles. In addition, it is found that the start and peak times of particle injections are between the onset and peak times of flare for the two events. Furthermore, we have models for the peak intensity of the particle source and the time interval from the onset of flares to the peak time of the particle source. We show that the models agree well with the best fit parameters.