  Condensation and sublimation of ices at the surface of the planet is a key
part of both the Martian H$_2$O and CO$_2$ cycles, either from a seasonal or
diurnal aspect. While most of the ice is located within the polar caps, surface
frost is known to be formed during nighttime down to equatorial latitudes.
Here, we use data from the Emirates Mars Infrared Spectrometer (EMIRS) onboard
the Emirates Mars Mission (EMM) to monitor the diurnal and seasonal evolution
of the ices at the surface of Mars over almost one Martian year. The unique
local time coverage provided by the instrument allows us to observe the
apparition of equatorial CO$_2$ frost in the second half of the Martian night
around the equinoxes, to its sublimation at sunrise.
