Relativistic Microburst Scale Size Induced by a Single Point-Source Chorus Element

Relativistic microbursts are impulsive, sub-second precipitation bursts of relativistic electrons. They are one of the main loss mechanisms of outer radiation belt electrons, and are driven by chorus waves. The scale size of relativistic microbursts is still not fully understood. In this work a global modeling of the microburst spatial distribution is conducted to study the scale size of relativistic microburst induced by chorus waves. A primary precipitation burst is induced near the source region by quasi-parallel waves, and a secondary precipitation (SP) is induced on higher L-shells by further-propagating, oblique waves. The SP has a significant scale size even with a point-source assumption because of wave spreading due to propagation effect. The secondary relativistic microburst scale size is similar to 40(20) km on the counter (co)-streaming side, consistent with previous observations. Our modeling results indicate chorus wave propagation effects are one of the primary factors controlling the relativistic microburst scale size.