https://www.zmescience.com/science/news-...volcanoes/
EXCERPTS: Every year around Mars’ southern solstice, a strange elongated ice cloud forms over the red planet’s surface. The exact nature of this peculiar meteorological phenomenon has been elusive — until recently. [...] The tubular cloud forms and fades daily for about 80 days or so of a Martian year — which lasts about 687 Earth days — stretching from the Arsia Mons volcano to Olympus Mons [1,100-mile-long or 1,800 km], which just happens to be the tallest mountain in the solar system.
You might think that the clouds are the result of volcanic eruptions, given the proximity to volcanoes. However, Mars isn’t volcanically active anymore. That being said, the volcanoes are indeed responsible for forming the elongated Martian cloud, but not in the way you likely imagine. [...] Once all of this data was pooled together, it quickly emerged that the Martian cloud is “orographic” or a “lee” cloud, meaning it forms when the atmosphere is pushed upward by surface features such as mountains — or in this particular case, very tall volcanoes with a leeward slope facing downwind.
As the moist air is forced up the volcano slope before sunrise, it eventually condenses higher up in the atmosphere where it’s much colder. Once the cloud reaches its maximum extent, it’s pushed westwards by high-altitude winds, before evaporating in the late morning when temperatures rise. The cloud only lasts for about two and a half hours, following a self-repeating cycle for 80 days or more every year.... (MORE - details)
RELATED (scivillage): A weird elongated cloud has manifested again on Mars
EXCERPTS: Every year around Mars’ southern solstice, a strange elongated ice cloud forms over the red planet’s surface. The exact nature of this peculiar meteorological phenomenon has been elusive — until recently. [...] The tubular cloud forms and fades daily for about 80 days or so of a Martian year — which lasts about 687 Earth days — stretching from the Arsia Mons volcano to Olympus Mons [1,100-mile-long or 1,800 km], which just happens to be the tallest mountain in the solar system.
You might think that the clouds are the result of volcanic eruptions, given the proximity to volcanoes. However, Mars isn’t volcanically active anymore. That being said, the volcanoes are indeed responsible for forming the elongated Martian cloud, but not in the way you likely imagine. [...] Once all of this data was pooled together, it quickly emerged that the Martian cloud is “orographic” or a “lee” cloud, meaning it forms when the atmosphere is pushed upward by surface features such as mountains — or in this particular case, very tall volcanoes with a leeward slope facing downwind.
As the moist air is forced up the volcano slope before sunrise, it eventually condenses higher up in the atmosphere where it’s much colder. Once the cloud reaches its maximum extent, it’s pushed westwards by high-altitude winds, before evaporating in the late morning when temperatures rise. The cloud only lasts for about two and a half hours, following a self-repeating cycle for 80 days or more every year.... (MORE - details)
RELATED (scivillage): A weird elongated cloud has manifested again on Mars