Impact of May 2024 ICME Event on Martian UV Dayglow Emissions using MAVEN/IUVS and EMM/EMUS Observations

We present first near-simultaneous observations of large-scale spatial response of the Martian H Lyman-{\alpha} and atomic oxygen dayglow emissions (O(3S) 130.4 nm and O(5S) 135.6 nm) during May 2024 interplanetary coronal mass ejection (ICME).

Using coordinated near-simultaneous observations from MAVEN/Imaging Ultraviolet Spectrograph (IUVS) and the EMM/Emirates Mars Ultraviolet Spectrometer (EMUS), we have identified pronounced enhancements in all three emissions relative to quiet-time conditions.

Interestingly, coordinated IUVS limb and EMUS disk observations reveal that ICME-driven response extends vertically through the thermosphere and horizontally across broad ranges of latitude, longitude, local-time, and solar zenith angle.

Concurrent enhancement of hydrogen and oxygen emissions indicates the simultaneous contribution of proton and electron-driven excitation mechanisms during ICME.

These findings reveal a novel planetary-scale response of the Martian dayglow.

By highlighting the critical role of energetic-particle precipitation in amplifying this global response, our work carries crucial implications for understanding Martian thermospheric response during intense solar transients.