Understanding the dynamics of relativistic and ultra-relativistic electrons in the Earth’s outer radiation belt remains one of the most important and fundamental challenges in space physics. Whilst significant advances have been made in understanding the impact of various competing acceleration and loss processes, the loss of ultra-relativistic electrons from low L-shells near the Earth remains largely unexplained. Pitch angle scattering of ultra-relativistic electrons into the atmosphere by electromagnetic ion cyclotron (EMIC) waves is commonly invoked to explain the observed flux dropouts, especially on low L-shells However, EMIC waves are challenging to detect by high altitude low inclination spacecraft such as the Van Allen probes due to the narrow spatio-temporal localization of the EMIC waves. Here we demonstrate how data from the Swarm satellites can be used to provide a high spatio-temporal monitor for EMIC waves which might be responsible for the loss of ultra-relativistic electrons on low L-shells measured by the Van Allen probes during geomagnetic storms.