Survey of Waves in the Ion Diffusion Region of Asymmetric Reconnection in the Dayside Magnetopause

Wave modes in the ion diffusion region of an active dayside reconnection site are characterized using high time-resolution data from NASA's Magnetospheric Multiscale (MMS) mission. We observe high-amplitude, low-frequency ($\leq \omega_{LH}$) electrostatic fluctuations near the magnetospheric-side separatrices, which are most likely a result of the lower hybrid drift instability (LHDI). In the magnetospheric upstream region we find whistler waves with $\omega\approx \Omega_e/2$ and phase velocity near $5\times 10^7\hspace{2pt}m/s$ propagating toward the X-line. In the exhaust region we find a largely different set of electromagnetic waves, including an obliquely-propagating, high-frequency ($\omega>\omega_{LH}$), left-hand-polarized waves with phase velocities around $1\times 10^6\hspace{2pt}m/s$. Possible relationships between these waves and local distribution functions will be investigated through analysis of data from the fast plasma instrument (FPI). We will also discuss the possibility of mode conversion from electrostatic lower hybrid waves to the electromagnetic waves we observe.