It's been well known for a long time Mars has two ice caps. B. It is established that Martian poles expand and contract with the seasons as do Earth's. When snow or ice appears it precipitates. E. Atmospheric cloud formations have also been photographed on Mars, therefore moisture must have sublimated directly from the ice caps or evaporated from surface water into the Martian atmosphere to create them.
Physics being universal, it's pretty safe to say both happen on Mars.
It stands to reason you will find more evidence of them near the edges of the ever changing Martian ice caps. Examine the edges of whatever ice cap is currently shrinking and you are bound to see your reflection. H. A constantly changing darkening of the Martian landscape has been observed for years. As the poles on Mars shrink and grow continuously, there must be a source of atmospheric and therefore surface water to create the snow and ice. If all available water was underground as some have suggested, the cycle would be broken and the poles would gradually disappear or at least stabilize.