Inner Magnetospheric Response to the Interplanetary Magnetic Field <i>B</i> _<i>y</i> Component: Van Allen Probes and Arase Observations

We utilize 17 years of combined Van Allen Probes and Arase data to statistically analyze the response inner magnetosphere orientation interplanetary magnetic field (IMF) By component. Past studies have demonstrated that IMF component introduces a similarly oriented into magnetosphere. However, these tended focus on lines in magnetotail only reaching as close Earth geosynchronous orbit. exploiting from magnetospheric spacecraft, we been able investigate at radial distances <7RE. When subtracting background values, provided by T01 IGRF models, find does affect configuration This control is observed throughout magnetosphere, across both hemispheres, all distances, local time sectors. The ratio residual, also known “penetration efficiency,” found be ?0.33. Bz increase, or inhibit, this depending upon its orientation.