Scientists have shown that regional dust storms play an unexpectedly a huge role in the loss of Water Mars, heating the cold Martian atmosphere at large altitudes and preventing the freezing of water vapor. As a result, the water molecule reaches the sparse layers of the gas shell, where they are decomposed on hydrogen and oxygen under the action of ultraviolet radiation. This is reported in the article published in the journal Nature Astronomy.
researchers believed that Mars lost most of its water to a large extent due to dust storms, but they did not realize the role of a significant impact of regional dusty storms, which occur almost every summer in the southern hemisphere of the planet. Global dust storms covering the entire planet and occurring every three or four Martian years were considered the main reason for the hottest summer months in the southern hemisphere, when Mars approaching the Sun to the minimum distance.
scientists analyzed the data obtained by the Mars Reconnaissance Orbiter orbital apparatus, which measured the temperature, the concentration of dust and water ice at a height of about 100 kilometers above the surface of Mars. Another apparatus – TRACE GAS ORBITER ESA (European Space Agency) – measured the concentration of water vapor and ice. Finally, the NASA MARS ATMOSPHERE AND VOLATILE EVOLUTION (MAVEN) space probe measured the amount of hydrogen, which leaves the water molecule at an altitude of 1000 kilometers above the surface.
TRACE GAS ORBITER spectrometers found water vapor in the lower layers of the atmosphere before the dusty storm starts. Typically, the temperature of the Martian atmosphere becomes colder with a height for most of the Martian year, which means that water vapor rising in the atmosphere freezes at relatively small heights. But when the dust storm began, the water vapor has reached large heights. The tools found 10 times more water in the middle atmosphere after the start of the dusty storm, which exactly coincides with the MARS Reconnaissance Orbiter data.
It is expected that at large altitudes of water steam under the influence of ultraviolet radiation of the Sun split into hydrogen and oxygen. Maven observations confirmed this by fixing the glow of the upper layers of the atmosphere caused by hydrogen, the concentration of which during a storm increased by 50 percent.