Photo of and by the Curiosity rover. Credit: NASA.

The Mars Reconnaissance Orbiter (MRO) has provided NASA with information that now makes scientist conclude that there might be more water in the atmosphere of Mars than Earth.

The MRO data on the water-ice clouds on Mars indicates substantial amounts of water. And the lead author of the new report, Armin Kleinboehl at NASA’s Jet Propulsion Laboratory in Pasadena, believes that the water-ice clouds possibly explains the rise and fall of temperature in the Martian atmosphere that occurs twice daily. A pattern that is occurring everywhere on Mars, and all year around.

The findings have been published in the Geophysical Research Letters and the scientists believe that the daily temperature fluctuations are probably driven by variations between day and night, so-called atmospheric tides. On Earth, we have something similar, but then with the Moon as the driver behind the fluctuations.

Kleinboehl writes; “We were surprised to find this strong twice-a-day structure in the temperatures of the non-dusty Mars atmosphere. While the diurnal tide as a dominant temperature response to the day-night cycle of solar heating on Mars has been known for decades, the discovery of a persistent semi-diurnal response even outside of major dust storms was quite unexpected, and caused us to wonder what drove this response.”

The researchers have been able to replicate the effects in computer climate models which including the water-ice clouds. As these clouds absorb infrared light coming from the planet’s surface, that absorption is enough to heat the middle atmosphere each day.

“We think of Mars as a cold and dry world with little water, but there is actually more water vapor in the Martian atmosphere than in the upper layers of Earth’s atmosphere,” Kleinboehl ads.

Mars Water-Ice Clouds Are Key to Odd Thermal Rhythm