  Using numerical simulations of charged-particles propagating in the
heliospheric magnetic field, we study small-scale gradients, or "dropouts", in
the intensity of solar energetic particles seen at 1 AU. We use two turbulence
models, the foot-point random motion model (Jokipii & Parker 1969; Giacalone et
al. 2006) and two-component model (Matthaeus et al. 1990), to generate
fluctuating magnetic fields similar to spacecraft observations at 1 AU. The
turbulence models include a Kolmogorov-like magnetic field power spectrum
containing a broad range of spatial scales from those that lead to large-scale
field-line random walk to small scales leading to resonant pitch-angle
scattering of energetic particles. We release energetic protons (20 keV - 10
MeV) from a spatially compact and instantaneous source. The trajectories of
energetic charged particles in turbulent magnetic fields are numerically
integrated. Spacecraft observations are mimicked by collecting particles in
small windows when they pass the windows at a distance of 1 AU. We show that
small-scale gradients in the intensity of energetic particles and velocity
dispersions observed by spacecraft can be reproduced using the foot-point
random motion model. However, no dropouts is seen in simulations using the
two-component magnetic turbulence model. We also show that particle scattering
in the solar wind magnetic field needs to be infrequent for intensity dropouts
to form.
