Presentation #208.06 in the session Sun-to-Earth Campaign-style Study of Large Space Weather Events.
Solar energetic particles (SEPs) erupt from the sun or are accelerated at the shocks associated with coronal mass ejections. Using the Van Allen Probes identically-instrumented satellites, along with ACE and GOES, we will report on the transient of SEP events as they move from interplanetary space into the near-equatorial inner magnetosphere. We will discuss a few large SEP events, along with examining larger statistical trends of SEP events observed in the inner magnetosphere from 2013-2017. Addressing the variety of factors that affect energetic particle cutoff rigidity in both large SEP events and small SEP events gives a larger framework to understand the connectivity between the inner magnetosphere and interplanetary space. We will demonstrate the factors that control cutoff rigidity are more complex than theory anticipates, leading to more significant space weather risks to inner-magnetospheric satellites.