Typical Characteristics of Whistler Mode Waves Categorized by Their Spectral Properties Using Van Allen Probes Observations

Abstract

Properties of banded, no-gap, lower band only, and upper band only whistler mode waves (0.1–0.8fce) outside the plasmasphere are investigated using Van Allen Probes data. Our analysis shows that no-gap whistler waves have higher occurrence rate at morning side and dayside, while banded and lower band only waves have higher occurrence rate between midnight and dawn. We also find that the occurrence rate of no-gap whistler waves peaks at magnetic latitude |MLAT|∼8–10°, while banded waves have higher occurrence rate near the equator for (Formula presented.) °. The wave normal angle distributions of these four groups of waves are similar to previous results. The distinct local time and latitudinal distribution of no-gap and banded whistler mode waves is critical to further understand the formation mechanism of the power minimum at half electron gyrofrequency.