Mars' Hidden Engine: Gravity Waves Powering Planetary Winds

Studies Reveal Role of Atmospheric Gravity Waves in Mars' Air Currents
The recent study that made room for scholars from the University of Tokyo identified atmospheric gravity waves as a key source of air currents on Mars, especially high above the planet's surface. The long-term atmospheric data research gives new insight into Mars' middle atmosphere dynamics and how it contrasts with that of the Earth.

The research used the techniques of Earth's atmospheric science to monitor Mars' planetary circulation. The research indicates that gravity waves control the impact of Martian middle atmosphere mid and high latitudes. Enormous atmospheric waves in Earth, also referred to as Rossby waves, are the stratospheric air movements' motor. Mars does not operate similarly, though, since gravity waves play a large role in managing atmospheric movement.

Understanding Gravity Waves on Mars
Gravity waves result when an air packet oscillates as a result of buoyancy variations. Unlike directly observable Rossby waves, gravity waves are small scale and hence have to be inferred indirectly. The research problem is sparse observation data such that their impact on Mars' atmosphere cannot easily be quantified.

Steer clear of this through scientists' utilization of the Ensemble Mars Atmosphere Reanalysis System (EMARS) data set that was built up from several decades' worth of measurements through space. Through this, there was an allowance to study Martian atmospheric seasonality. What was learned by researchers is that gravity waves enable rapid vertical transmission of angular momentum, which is among the reasons why there is north-south atmospheric circulation. This reminds one of Earth-like motion in the mesosphere and not in the stratosphere.

Implications for Martian Weather Models
The finding indicates that current Mars atmospheric circulation models will need to be re-written so they will include more realistic portrayals of gravity waves. Fresh models of that type would lead to improved predictions of Martian climate and weather and aid in future exploration and research missions.

Mars' axial inclination and rotation period are similar, if not identical, to those of Earth and can therefore be used as a terrestrial planetary weather system model. Its low, carbon dioxide-dense atmosphere and high seasonal contrasts, however, present special challenges due to their impact on the atmospheric models. In order to get an awareness of such differences, researchers can refine their models of the atmosphere so that they are more precise and, ultimately, may lead to improved simulation of the Martian, as well as the Earth's, climate.

Future Research on Martian Dust Storms
Scientists plan to continue to broaden their studies to investigate the influence of Martian dust storms on atmospheric circulation. To this point, their studies have focused on years with minor storms, but large storms have a profoundly different impact on atmospheric conditions. The new research will seek to find out if gravity waves are even more important in these types of storms.

By discovering what Martian atmospheric conditions would be like, scientists are already well on their way to being able to accurately predict atmospheric conditions on the planet. This data will prove extremely useful for planners of missions and the protection of astronauts' and robots' health.

Source:

University of Tokyo