Characteristics of Rising Tone Whistler Mode Waves Inside the Earth's Plasmasphere, Plasmaspheric Plumes, and Plasmatrough

Abstract

Whistler mode waves, particularly rising tone emissions, are important for nonlinear interactions with energetic electrons in the Earth's magnetosphere. In this letter, we evaluate the characteristics of rising tone whistler mode waves in three distinct regions: (1) inside the plasmasphere, (2) plasmapheric plumes, and (3) plasmatrough (outside the plasmapause). Our statistical results indicate that the occurrence rate of rising tone emissions tends to increase with increasing geomagnetic activity and is highest in plasmaspheric plumes among these three regions. Inside the plasmasphere, rising tone emissions typically occur in the outer portion of the plasmasphere, particularly near the dawnside. Moreover, the rising tone emissions inside the plasmasphere and plumes tend to be more field aligned than those in the plasmatrough. Our new findings of global wave properties of rising tone emissions are critical for understanding the generation of rising tone emissions and their effects on radiation belt electron dynamics.