Statistical Characteristics in the Spectrum of Whistler Waves Near the Diffusion Region of Dayside Magnetopause Reconnection

Abstract

Using Magnetospheric Multiscale (MMS) data, we present a statistical analysis revealing characteristics in the frequency spectrum of whistler waves in the vicinity of the diffusion region of magnetopause reconnection. On the magnetosphere side of reconnection, whistler waves are highly centered around the 1/2 electron cyclotron frequency (Ωe). On the magnetosheath side of reconnection, whistler waves are mainly below 1/2 Ωe and peaked around 0.2 Ωe. The electron temperature anisotropy associated with the waves is evaluated. The occurrence rate of the whistler waves is large in the presence of perpendicular electron temperature anisotropy (Te⊥/Te‖ > 1). However, a large part of the whistler waves events occurs in association with parallel electron temperature anisotropy (Te⊥/Te‖ < 1) on the magnetosheath side of reconnection, reflecting a large number of the total observations with this electron condition. These results shed new lights on the whistler-related electron kinetic processes near the reconnection diffusion region.