In Search of New Impacts of Cold Electrons on Whistler Waves: Oblique Whistlers and High-Frequency Turbulence Driven by Drift Instabilities

Cold electrons (<10 eV) have been suggested as a catalyst for dissipation of field-aligned whistler waves (Roytershteyn and Delzanno, PoP 2021). The mechanism is a drift instability, where the whistler wave electric field induces a drift in the cold electrons relative to the background ions. The resulting instability generates both oblique whistler waves and short wavelength electron-Bernstein mode waves spread in a range of frequencies. We present results of a statistical search through EMFISIS data from the Van Allen Probes mission, comparing the occurrence rate of both high and low wave-normal-angle whistlers with the presence of higher-than-average electrostatic wave power above 5fce, observed in some individual events. For these cases where there is evidence for the cold-electron-driven turbulence, we also characterize the presence of low energy electrons in HOPE data in a subset where photoelectron contamination is limited.