Scientists map water vapor on Mars

Chuck Bednar for redOrbit.com – Your Universe Online
Using data collected over a 10-year period by instruments on the Mars Express orbiter, Russian scientists have created a map of water vapor distribution in the atmosphere of the Red Planet, the Moscow Institute of Physics and Technology (MIPT) have announced.
The MIPT researchers, along with colleagues at the Space Research Institute of the Russian Academy of Sciences and from institutions in France and the US, recorded seasonal variations in the atmospheric concentrations using the Spectroscopy for Investigation of Characteristics of the Atmosphere of Mars (SPICAM) spectrometer.
According to the researchers, this marks the longest period of observation and provides the largest volume of data about water vapor on Mars. The Space Research Institute and MIPT staff, as well as experts from the French laboratory LATMOS and NASA’s Goddard Space Flight Center analuzed data obtained from SPICAM’s spectrometer over a period of five Martian years (or approximately 10 Earth years, since one Mars year is equal to 1.88 Earth years).
While the original SPICAM was lost in the 1990s, a new and upgraded version was built as part of an agreement between the Russian space agency Roscosmos and their French counterparts, CNES, for the Mars Express orbiter. It was launched in June 2003, and at the end of December of that year, Mars Express entered a near-Mars orbit and started collecting data on the planet.
The low temperatures and low atmospheric pressure on Mars prevents water to exist in liquid form in open reservoirs like it would on Earth, the researchers said. However, the planet does have a layer of permafrost, with large reserves of frozen water concentrated at the polar caps, and there are also low levels of water vapor in the atmosphere, they noted.
Based on their calculations, if the entire volume of water in the atmosphere was spread evenly across the planet’s surface, the thickness of the water layer would not exceed 10-20 microns, or less than one-one thousandth of what a similar layer would look like on Earth.
Using SPICAM, the scientists were able to create a picture of the annual cycle of water vapor concentration variation in the atmosphere. They found that the water vapor content in the atmosphere researches a maximum level of 60-70 microns of released water in the northern regions during the summer season.
In the southern hemisphere, this summer maximum is significantly lower, measuring only about 20  microns, they said. The data also revealed that a significant 5 to 10 micron reduction in water vapor concentration occurs during global sandstorms. They believe that this is linked to the removal of atmospheric water due to adsorption processes and condensation on surfaces.
“This research, based on one of the longest periods of monitoring of the Martian climate, has made an important contribution to the understanding of the Martian hydrological cycle – the most important of the climate mechanisms which could potentially support the existence of biological activity on the planet,” explained co-author Alexander Rodin, deputy head of the Infrared Spectroscopy of Planetary Atmospheres Laboratory at MIPT and senior scientific researcher at the Space Research Institute.
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