Persistent pitch angle anisotropies of relativistic electrons in the outer radiation belts

Pitch Angle Distributions in the radiation belts are well characterized with sinnα. By tracking the exponent ‘n’, termed Pitch Angle Index, we are able to observe persistent and cross energy changes in pitch angle distributions of Van Allen radiation belt electrons using Van Allen Probes particle observations. The pitch angle distributions measurements are well fit down to a single satellite spin, and therefore can track spatially and temporally confined changes to determine connection between particles and waves. We use the Van Allen Probes data in conjunction with Geostationary Operational Environmental Satellites (GOES) spacecraft and several ground magnetometer stations from Canadian Array for Realtime Investigations of Magnetic Activity (CARISMA) and Finnish pulsation magnetometer network of Sodankylä Geophysical Observatory (SGO) to connect particles that become very anisotropic to electromagnetic ion cyclotron (EMIC) waves during a quiet period over two days, June 26 and 27, 2013. The waves and peaks in the particle PADs are both long lasting but spatially separated, suggesting that wave particle interactions in the inner magnetosphere can occur for extend periods of time and have significant impact on the global radiation belts, even during otherwise geomagnetically quiet times and when wave activity is highly localized.